Abstract
Nanocomposites with diameters of 1 to 100 nm have modified properties such as uniform size distribution, small size, high surface-to-volume ratio, high absorbability, porosity, and various potential roles, including in catalytic and biological activities. The purpose of this research study was to systematically review all research studies on the photocatalytic decomposition of pollutants by NiFe2O4-based nanocomposites and evaluate the optimal laboratory conditions and the results of these studies. The present systematic review was conducted by searching Scopus, PubMed and Web of Science databases until March 2022. The parameters of nano catalyst type and size, synthesis methods, pollutant type, optimal pH, optimal initial pollutant concentration, optimal catalyst concentration, optimal time, radiation and removal efficiency were investigated. 454 studies were screened and using the inclusion and exclusion criteria, in total, 31 studies met our inclusion criteria and provided the information necessary to photocatalytic degradation of pollutants by NiFe2O4-based nanocomposites. In the investigated studies, the percentage of photocatalytic degradation of pollutants by NiFe2O4-based nanocomposites was reported to be above 70%, and in some studies, the removal efficiency had reached 100%. From the results of this systematic review, it was concluded that the photocatalytic process using NiFe2O4-based nanocomposites has a high effect on the degradation of aqueous solution pollutants.
HIGHLIGHTS
454 studies were screened and using the inclusion and exclusion criteria, in total, 31 studies met our inclusion criteria.
The percentage of photocatalytic degradation of pollutants by NiFe2O4-based nanoparticles was reported to be above 70%, and in some studies, the removal efficiency had reached 100%.
ABBREVIATIONS
- PRISMA
Preferred Reporting Items for Systematic Reviews and Meta-Analyses
- NiFe2O4-based nanoparticle
nanocomposites that have Nickel Ferrite in their structures
- Photocatalyst
is a combination of two words: photo related to photon and catalyst, which is a substance altering the reaction rate in its presence.
- MB
methylene blue dye
- IBP
influence of persulfate on ibuprofen
- RhB
rhodamine B
- UDMH
unsymmetrical dimethylhydrazine
- CP
chlorpyrifos
- AMP
ampicillin
- EBT
Eriochrome Black T
- SMX
sulfamethoxazole
- TC
tetracycline hydrochloride
- MG
malachite green
- IC
indigo carmine
- NZF
Ni0.5Zn0.5Fe2O4 nanocomposites
INTRODUCTION
The rapid increase of populations causes the increase of non-degradable and toxic organic pollutants in water environments such as pharmaceuticals, dyes, aromatic compounds, acids etc (Naghizadeh et al. 2015; Azam et al. 2021; Xiao et al. 2021; Esmati et al. 2023). The rapid increase in industries has also increased water pollution and energy problems. Energy problems and water pollution are among the problems of the present age that threaten humans (Guo et al. 2021; Nawaz et al. 2022). Therefore, humans need a sustainable, efficient, and accessible technology to overcome the problem of water pollution. Considering the green and sustainable nature of sunlight, using solar energy with nanocomposites in water purification is a cost-effective and environmentally friendly method (Tang et al. 2019; Xie et al. 2020; Javadmoosavi et al. 2023). Nanoscience and nanotechnology can be used in various sciences such as water purification, textile, pharmaceutical, medicine, and printing, as well as today in the environment in order to remove many pollutants (Naghizadeh et al. 2013; Ren et al. 2019; Shams et al. 2019; Derakhshani et al. 2023). So far, a lot of research has been done on the synthesis of different nanomaterials and their application in different fields (Mousavi & Habibi-Yangjeh 2016; Mousavi-Kamazani et al. 2016; Ghoreishi et al. 2018; Shirzadi-Ahodashti et al. 2020b; Gholami et al. 2023). Nanocomposites with diameters between 1 and 100 nm have improved properties such as uniform size distribution, small size, high surface-to-volume ratio, high adsorption capacity, porosity, and various potential roles in catalytic and biological activities. For these reasons, nanocomposites have recently been synthesized and widely used in the removal of various pollutants from aqueous solutions (Khan et al. 2016; Akbari et al. 2019; Shams et al. 2019). Today, extensive efforts have been made to investigate the efficiency of spinel ferrites (MFe2O4) due to their unique physical and chemical properties (Polshettiwar et al. 2011; Jiang et al. 2020). In the past decades, various advanced methods have been used to synthesize different spinel ferrites, including the co-precipitation method, hydrothermal method, sol–gel method, mechanical alloying, solution thermal method, electrochemical synthesis, and chemical solution deposition method (Yan et al. 2013; Naghizadeh et al. 2017). Nowadays, Nickel ferrite (NiFe2O4) is known as an important spinel ferrite and has been studied in various fields due to its chemical stability and mechanical hardness. Today, composites derived from NiFe2O4 are used as photocatalysts for the decomposition of various pollutants in aqueous solutions (Hossein Panahi et al. 2020; Wang et al. 2022). Magnetic semiconductor photocatalysts are used in various environmental fields, including water and wastewater treatment, due to their high optical activity, non-toxicity, low cost, easy application in various environmental conditions, complete mineralization of pollutants, and chemical and thermal stability (Eslami et al. 2016; Ge et al. 2021; Sanadi et al. 2021; Derakhshani et al. 2022). Photocatalysts are materials that create a pair of electron holes on their surface as a result of sunlight or artificial light (such as UV light) so that the free radicals produced from this process have high oxidizing properties to destroy pollutants (Kamani et al. 2018; Asadzadeh Patehkhor et al. 2021). Photocatalysts actually provide the necessary conditions to carry out these reactions, but do not directly interfere with oxidation–reduction reactions. The obvious feature of a semiconductor photocatalyst is having capacitive and conductive bands. The space between these two bands is called the band gap (Bora & Dutta 2014; Shirzadi-Ahodashti et al. 2020a). The operation of a semiconductor photocatalyst is initiated by the irradiation of natural or artificial light on its surface. During light irradiation, due to the absorption of photons with energy equal to or greater than the energy of the photocatalytic band gap, the electrons of the capacitive band are excited and transferred from this band to the conduction band, and as a result of this transfer, the holes are simultaneously formed in capacitive bands. The lifetime of the electron–hole pair is only a few nanoseconds. But this short time is enough to carry out oxidation/reduction reactions in a solution containing a semiconductor. The created holes have a very high oxidation potential so that they are sufficient to produce hydroxyl radicals from water molecules and hydroxide ions adsorbed on the photocatalyst surface. The generated electrons react with the absorbed oxygen molecule and reduce it to superoxide radical. The superoxide radical produced reacts with a proton to form peroxide radicals. Hydrogen peroxide can also act as an electron acceptor and generate additional hydroxyl radicals (Safari et al. 2014; Shirzadi-Ahodashti et al. 2020b). So far, a complete systematic analysis has not yet been published to investigate the photocatalytic decomposition of pollutants by NiFe2O4-based nanocomposites in aqueous solutions. Therefore, in this study, our aim was to systematically review all research studies on the photocatalytic decomposition of pollutants by NiFe2O4-based nanocomposites and to evaluate the laboratory conditions and results of these studies.
METHODS
The present review research study was followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines (http://www.prisma-statement.org/).
Inclusion criteria
We included all the original studies in English that investigated the photocatalytic degradation of pollutants in aqueous solutions using NiFe2O4-based nanocomposites. In all the studies reviewed in this research, all the pollutants in water that were degraded by photocatalytic method by NiFe2O4-based nanocomposites were investigated.
Search strategy
The present study was a systematic review that was conducted by searching PubMed, Web of Science and Scopus databases until March 2022. The language of the searched articles was English. The search strategy in this systematic review is shown in Table 1. The following keywords were considered during the search:
Photodegradation, Photolysis, Photocatalysis, Photocatalytic, Photocatalyst, ‘Photochemical processes’, Nanoparticles, Nanocomposite, Nanoparticle, ‘Nanocrystalline Materials’, ‘Nanocrystalline Material’, Nanocrystals, Nanocrystal, NiFe2O4, ‘Nickel ferrite’, Water, ‘aqueous solution’.
Data extraction
Data and information extracted from studies that were eligible for inclusion in this systematic review included the following:
(I) authors, (II) year of publication, (III) catalyst type and size, (IV) methods of synthesis, (V) type of pollutant, (VI) optimum pH, (VII) optimum initial concentration of pollutant, (VIII) optimum catalyst concentration, (IX) optimum time, (X) irradiation, (XI) removal efficiency.
Other important parameters included antibacterial performance of the photocatalyst, effect of interference and reusability of the photocatalyst, regeneration and reusability of the photocatalyst, effect of NiFe2O4 content in nanocomposite, effect of different catalysts on the degradation of methylene blue (MB), effect of H2O2 in the photocatalysis process, the effect of UV light intensity, effects of the initial oxalic C(H2C2O4) concentration, sonophotocatalysis with variable ultrasonic power intensities, influence of ultrasonic power and frequency, influence of persulfate on ibuprofen (IBP) mineralization, the effect of US frequency.
Synthesis method
We conducted a systematic review and since the data were heterogeneous, we did not perform any specific analysis and the data were reported as a narrative.
RESULTS AND DISCUSSION
Among the reviewed articles, the most recent article selected for systematic review was published in 2022 and the oldest was published in 2012. All investigated articles were in English. The studies were conducted in South Korea, India, Iran, Turkey, Philippines, Taiwan, United States of America, China, Indonesia, Saudi Arabia, Yemen, Sudan, and South Africa.
In most studies, optimum initial concentration of pollutants, optimum catalyst concentration, optimum pH and optimum time were investigated. In all these studies, nanocomposites based on NiFe2O4 were used, including: Ag/AgBr/NiFe2O4 (Ge et al. 2017), Ag–doped Ni0.5Zn0.5Fe2O4 (Mustafa & Oladipo 2021), CdS–NiFe2O4/rGO (Bagherzadeh et al. 2018), ZIF-8/NiFe2O4 (Faraji et al. 2021), GO/NiFe2O4/TiO2 (Lu et al. 2021), NiFe2O4 (Liu et al. 2012; Kazemi et al. 2018; Guo & Wang 2019; Nadumane et al. 2019; Vijay et al. 2019; Nawaz et al. 2020; Hariani et al. 2021), NiFe2O4 :Mg2+ (Nadumane et al. 2019), cysteine modified graphene oxide@nickelferrite@titanium dioxide (Anirudhan et al. 2021), Pectin- NiFe2O4 (Gupta et al. 2020), NiFe2O4/ZnO (Moradi et al. 2018; Yeganeh et al. 2020), PANI/Ag3PO4/NiFe2O4 (Chen et al. 2019a), NiAlxFe2−xO4 (x = 0–0.7) (Naik et al. 2018), MWCNTs-CuNiFe2O4 (Al-Musawi et al. 2021), CdS nanorods/NiFe2O4/NaX zeolite (Sadeghi et al. 2020), Z-scheme APO/MOF/NFO (Zhou et al. 2018), NiFe2O4/T/GOx (Atacan et al. 2019), NiFe2O4@GO (Bayantong et al. 2021), NiFe2O4-rice husk char (RHC) (Han et al. 2018), NiFe-CNT (Nawaz et al. 2020), NiFe2O4/C yolk-shell (Chen et al. 2019b), Chitosan-Ascorbic Acid@NiFe2O4 (CTAS@NIFE) (Hasan et al. 2020), TiO2−x/NiFe2O4 (Wu 2020), NiFe2O4–SQD (NF–SQDs) (Babu et al. 2021), MWCNT–CuNiFe2O4 (Al-Musawi et al. 2022), NiFe2O4/MWCNTs/ZnO (Hezam et al. 2020), ((NiFe2O4-SiO2), (NiFe2O4-TiO2), (NiFe2O4-SiO2-TiO2) and TiO2) (Ojemaye et al. 2017).
Different pollutants in aqueous solutions were degraded by using these nanocomposites. In nine studies the pollutant investigated was methylene blue (Bagherzadeh et al. 2018; Han et al. 2018; Kazemi et al. 2018; Guo & Wang 2019; Gupta et al. 2020; Hezam et al. 2020; Sadeghi et al. 2020; Bayantong et al. 2021; Faraji et al. 2021). Other pollutants included Rhodamine B (RhB) (Liu et al. 2012; Ge et al. 2017; Zhou et al. 2018; Chen et al. 2019a; Sadeghi et al. 2020), Metronidazole antibiotic (Mustafa & Oladipo 2021), Unsymmetrical dimethylhydrazine (UDMH) (Lu et al. 2021), (IC dye and Phenol) (Nadumane et al. 2019), Chlorpyrifos (CP) (Anirudhan et al. 2021), Remazol Black 5 (Gupta et al. 2020), Coomassie blue G-250 dye (Yeganeh et al. 2020), Methyl orange (MO) dyes (Chen et al. 2019a; Sadeghi et al. 2020), (blue 129 dye and reactive blue 21 dye) (Moradi et al. 2018), Rose bengal (RB) dye (Naik et al. 2018), Ampicillin (AMP) (Al-Musawi et al. 2021), Eriochrome Black T (EBT) (Sadeghi et al. 2020), Indigo Carmine (IC) (Atacan et al. 2019), Sulfamethoxazole (SMX) (Nawaz et al. 2020), Irgalite violet dye (Vijay et al. 2019), Tetracycline hydrochloride (TC) (Chen et al. 2019b), Malachite green (MG) (Hasan et al. 2020), ibuprofen (IBP) (Wu 2020), Congo red (Hariani et al. 2021), Tetracycline (TC) (Babu et al. 2021), Acid blue 113 dye (Al-Musawi et al. 2022), and Cr(VI) (Ojemaye et al. 2017).
The removal efficiency in most studies shows that NiFe2O4-based nanocomposites can remove pollutants from aqueous solutions by photocatalytic degradation process with a high percentage.
Influence of pH on photocatalytic activity of NiFe2O4-based nanocomposites
Table 2 also shows the experimental conditions and the investigated variables used in the included studies for the degradation of environmental pollutants from aqueous solutions by photocatalytic process using NiFe2O4-based nanocomposites. pH is one of the most important factors in the photocatalytic degradation process (Li et al. 2016). The optimum pH for the photocatalytic degradation of pollutants by NiFe2O4 was found to be equal to 2 based on two studies (Ojemaye et al. 2017; Han et al. 2018), equal to 2.5 in one study (Gupta et al. 2020), equal to 3 in five studies (Liu et al. 2012; Nadumane et al. 2019; Vijay et al. 2019; Nawaz et al. 2020; Yeganeh et al. 2020; Mustafa & Oladipo 2021), equal to 5 in four studies (Nawaz et al. 2020; Al-Musawi et al. 2021; Hariani et al. 2021; Al-Musawi et al. 2022), equal to 6 in one study (Wu 2020), equal to 6.5 in one study (Atacan et al. 2019), from 7 to 8 in seven studies (Bagherzadeh et al. 2018; Kazemi et al. 2018; Naik et al. 2018; Chen et al. 2019b; Guo & Wang 2019; Hasan et al. 2020; Anirudhan et al. 2021), equal to 6.8 in one study (Chen et al. 2019a), equal to 9 in two studies (Faraji et al. 2021; Lu et al. 2021), equal to 10 in two studies (Ge et al. 2017; Bayantong et al. 2021), in one study 11.5 (Hezam et al. 2020), and not reported in four studies (Moradi et al. 2018; Zhou et al. 2018; Sadeghi et al. 2020; Babu et al. 2021).
1 | (((((((Nanoparticles[Title/Abstract]) OR (Nanocomposite[Title/Abstract])) OR (Nanoparticle[Title/Abstract])) OR (‘Nanocrystalline Materials’[Title/Abstract])) OR (‘Nanocrystalline Material’[Title/Abstract])) OR (Nanocrystals[Title/Abstract])) OR (Nanocrystal[Title/Abstract])) OR (Nanoparticles[MeSH Terms]) |
2 | ((NiFe2O4[Title/Abstract]) OR (‘Nickel ferrite’ [Title/Abstract])) |
3 | ((((((Photolysis[MeSH Terms]) OR (‘photochemical processes’ [Title/Abstract])) OR (photocatalyst[Title/Abstract])) OR (photocatalytic[Title/Abstract])) OR (photocatalysis[Title/Abstract])) OR (Photolysis[Title/Abstract])) OR (Photodegradation[Title/Abstract]) |
4 | ((Water[Title/Abstract]) OR (‘aqueous solution’ [Title/Abstract])) OR (water[MeSH Terms]) |
5 | #1 AND #2 |
6 | #5 AND #3 |
7 | #6 AND #4 |
1 | (((((((Nanoparticles[Title/Abstract]) OR (Nanocomposite[Title/Abstract])) OR (Nanoparticle[Title/Abstract])) OR (‘Nanocrystalline Materials’[Title/Abstract])) OR (‘Nanocrystalline Material’[Title/Abstract])) OR (Nanocrystals[Title/Abstract])) OR (Nanocrystal[Title/Abstract])) OR (Nanoparticles[MeSH Terms]) |
2 | ((NiFe2O4[Title/Abstract]) OR (‘Nickel ferrite’ [Title/Abstract])) |
3 | ((((((Photolysis[MeSH Terms]) OR (‘photochemical processes’ [Title/Abstract])) OR (photocatalyst[Title/Abstract])) OR (photocatalytic[Title/Abstract])) OR (photocatalysis[Title/Abstract])) OR (Photolysis[Title/Abstract])) OR (Photodegradation[Title/Abstract]) |
4 | ((Water[Title/Abstract]) OR (‘aqueous solution’ [Title/Abstract])) OR (water[MeSH Terms]) |
5 | #1 AND #2 |
6 | #5 AND #3 |
7 | #6 AND #4 |
No. . | Nanocatalyst . | Size . | Synthesis methods . | Pollutant . | Optimum monitored parameters . | Irradiation method . | Removal efficiency . | References . | |||
---|---|---|---|---|---|---|---|---|---|---|---|
pH . | Pollutant concentration . | Catalyst concentration . | Time . | ||||||||
1 | Ag/AgBr/NiFe2O4 | 50–150 nm | Hydrothermal | Rhodamine B (RhB) | 10 | 10 mg/L | – | 60 min | visible light irradiation | – | Ge et al. (2017) |
2 | Ag–doped Ni0.5Zn0.5Fe2O4 | < 5 μm | co-precipitation | metronidazole antibiotic | 3 | 50 mg/L | 10 mg per 25 mL | 360 min | UV | – | Mustafa & Oladipo (2021) |
3 | CdS–NiFe2O4/rGO | 20–40 nm | hydrothermal | methylene blue (MB) | 7 | 10 mg/L | 0.4 g/L | 120 min | visible light | – | Bagherzadeh et al. (2018) |
4 | ZIF-8/NiFe2O4 | – | Hydrothermal and green method | methylene blue (MB) | 9 | 5 mg/L | 0.05 g | 120 min | visible-light | 94% | Faraji et al. (2021) |
5 | GO/NiFe2O4/TiO2 | Length: 1.65 μm diameter: 60–120 nm | TiO2 NRAs: hydrothermal | unsymmetrical dimethylhydrazine (UDMH) | 9 | 20 mg/L | – | 90 min | visible light | 73.1% | Lu et al. (2021) |
NiFe2O4/TiO2 NRAs: dipping and annealing | |||||||||||
GO : modified Hummers' method | |||||||||||
6 | NiFe2O4 | 62.2–9.28 μm | modified green sol–gel route | IC dye and Phenol | 3 | 20 ppm | 40 mg | 120 min | Sunlight irradiation | – | Nadumane et al. (2019) |
NiFe2O4: Mg2 + | 0.46–8.33 μm | ||||||||||
7 | Cysteine modified Graphene oxide@nickelferrite@titanium dioxide | – | – | chlorpyrifos (CP) | 7 | 10 mg/L | 2 g/L | 1 h | visible light irradiation | 99.5% | Anirudhan et al. (2021) |
8 | Pectin- NiFe2O4 | 15–20 nm | hydrothermal | Methylene blue & Remazol Black 5 | 2.5 | 0.05 mM | 0.5 g/L | Methylene blue: 35 min | visible light | Methylene blue: 99.57% | Gupta et al. (2020) |
Remazol Black 5: 30 min | Remazol Black 5: 99.68% | ||||||||||
9 | NiFe2O4/ZnO:ZnO | : 48–52 nm | solidification and calcination methods | Coomassie blue G-250 dye | 3 | – | 0.1 g | 60 min | Visible and UV light | – | Yeganeh et al. (2020) |
NiFe2O4 | 25–31 nm | ||||||||||
10 | PANI/Ag3PO4/NiFe2O4 | Precipitation hydrothermal method | Rhodamine B (RhB) and methyl orange (MO) dyes | 6.8 | Optimum initial concentration of RhB dye: 10 mg/L | 1 g/L | 30 min | visible-light | RhB: 100% | Chen et al. (2019a) | |
MO: 94.97% | |||||||||||
11 | NiFe2O4 | 155–185 nm | solvothermal process | Methylene Blue (MB) | 7 | 0.03 g/L | 0.2 g/L | 50 min | UV | 98.5% | Guo & Wang (2019) |
12 | NiFe2O4@ ZnO | 35–45 nm | green sol–gel method | blue 129 dye and reactive blue 21 dye | – | 2 mg/L | 0.05 g for DB129 and 0.07 g for RB21 | 60 min | visible light | blue 129 dye: 98% | Moradi et al. (2018) |
reactive blue 21 dye: 96% | |||||||||||
13 | NiAlxFe2 − xO4 (x = 0–0.7) | 19–38 nm | sol–gel auto-combustion method | rose bengal (RB) dye | 8 | 5 ppm/100 mL | 40 mg/100 ml | 150 min | visible light | 99.8% | Naik et al. (2018) |
14 | MWCNTs-CuNiFe2O4 | 2–14 nm | Co-precipitation | Ampicillin (AMP) | 5 | 25 mg/L | 0.5 g/L | 60 min | UV | 100% | Al-Musawi et al. (2021) |
15 | CdS nanorods/NiFe2O4/NaX zeolite: (NiFe2O4) | 15 nm | simple ultrasound-assisted solvothermal method | Methylene Blue (MB), Eriochrome Black T (EBT), Rhodamine B (RhB) and Methyl Orange (MO) | _ | 25 mg/L | 50 mg | 60 min | Ultrasonic | MB: 100% | Sadeghi et al. (2020) |
RhB: 97.4% | |||||||||||
EBT: 90% | |||||||||||
MO: 85.3% | |||||||||||
16 | Z-scheme APO/MOF/NFO | – | precipitation method | Rhodamine B (RhB) | _ | 5 mg/L | 0.4 g/L | _ | visible-light irradiation | _ | Zhou et al. (2018) |
17 | NiFe2O4/T/GOx | – | solvothermal method | Indigo Carmine (IC) | 6.5 | 10 mg/L | _ | 90 min | Bio-Fenton process & UV lamp | Bio-Fenton process: 37.6% | Atacan et al. (2019) |
UV lamp: 98.6% | |||||||||||
18 | NiFe2O4 | 20–25 nm | _ | Methylene Blue (MB) | 7.81 | 20 mg/L | 22.35 mg | 67 min | UV light irradiation | 95.8% | Kazemi et al. (2018) |
19 | NiFe2O4@GO | 7.76 nm | solution combustion synthesis route | Methylene Blue (MB) | 10 | 0.04 mM | 0.5 g/L | 120 min | UV light irradiation | _ | Bayantong et al. (2021) |
20 | NiFe2O4-rice husk char (RHC) | – | simple soft chemical way | Methylene Blue (MB) | 2 | 10 mg/L | _ | _ | Visible-Light Irradiation | _ | Han et al. (2018) |
21 | NiFe2O4- | 10 nm | Hydrothermal method | Rhodamine B (RhB) | 3 | 10 mg/L | 0.2 g/L | 30 min | UV | _ | Liu et al. (2012) |
22 | NiFe2O4 & NiFe-CNT | one-step hydrothermal treatment | sulfamethoxazole (SMX) | 5 | 5 ppm | 0.025 g/L | 2 h | ultraviolet (UV)-A & visible light | 100% | Nawaz et al. (2020) | |
23 | NiFe2O4 | Co-precipitation method | Irgalite violet dye | 3 | 400 ppm | 0.2 g | 60 min | sunlight | 99% | Vijay et al. (2019) | |
24 | NiFe2O4/C yolk-shell- | 200–400 nm | hydrothermal deposition method | tetracycline hydrochloride (TC) | 7.5 | _ | 0.3 g/L | 60 min | visible light irradiation | 97.25% | Chen et al. (2019b) |
25 | Chitosan-Ascorbic Acid@NiFe2O4 (CTAS@NIFE)- | 5.15 nm | chemical co-precipitation method | malachite green (MG) | 8 | 70 mg/L | _ | 90 min | visible light irradiation coupled with ultrasonic waves | 99% | Hasan et al. (2020) |
26 | TiO2−x/NiFe2O4 | – | Consecutive sol–gel processes | ibuprofen (IBP) | 6 | 10 mg/L | 0.7 g/L | 100 min | ultrasonic irradiation | 96.70% | Wu (2020) |
27 | NiFe2O4: | 10–40 nm | solution combustion method | Congo red | 5 | 100 mg/L | _ | 60 min | Visible light | 96.80% | Hariani et al. (2021) |
28 | NiFe2O4–SQD (NF–SQDs) | 54.37 nm | hydrothermal synthesis | tetracycline (TC) | _ | 40 mg/L | 15 mg | 70 min | sunlight irradiation | 98% | Babu et al. (2021) |
29 | MWCNT–CuNiFe2O4 | – | Co-precipitation | acid blue 113 dye | 5 | 50 mg/L | 0.6 g/L | 30 min | UV | 100% | Al-Musawi et al. (2022) |
30 | NiFe2O4/MWCNTs/ZnO | – | hydrothermal and the co-precipitation methods | Methylene Blue (MB) dye | 11.5 | 20 mg/L | 1 g/L | 300 min | visible light | 73.02% | Hezam et al. (2020) |
31 | (NiFe2O4-SiO2), (NiFe2O4-TiO2), (NiFe2O4-SiO2-TiO2) and TiO2 | – | Co-precipitation and sol–gel methods | Cr(VI) | 2 | _ | 200 mg | TiO2: 240 min | UV irradiation | TiO2: 96.7% | Ojemaye et al. (2017) |
(NiFe2O4-SiO2-TiO2): 300 min | (NiFe2O4-SiO2-TiO2): 96.50% | ||||||||||
(NiFe2O4-TiO2): 300 min | (NiFe2O4-TiO2): 60% |
No. . | Nanocatalyst . | Size . | Synthesis methods . | Pollutant . | Optimum monitored parameters . | Irradiation method . | Removal efficiency . | References . | |||
---|---|---|---|---|---|---|---|---|---|---|---|
pH . | Pollutant concentration . | Catalyst concentration . | Time . | ||||||||
1 | Ag/AgBr/NiFe2O4 | 50–150 nm | Hydrothermal | Rhodamine B (RhB) | 10 | 10 mg/L | – | 60 min | visible light irradiation | – | Ge et al. (2017) |
2 | Ag–doped Ni0.5Zn0.5Fe2O4 | < 5 μm | co-precipitation | metronidazole antibiotic | 3 | 50 mg/L | 10 mg per 25 mL | 360 min | UV | – | Mustafa & Oladipo (2021) |
3 | CdS–NiFe2O4/rGO | 20–40 nm | hydrothermal | methylene blue (MB) | 7 | 10 mg/L | 0.4 g/L | 120 min | visible light | – | Bagherzadeh et al. (2018) |
4 | ZIF-8/NiFe2O4 | – | Hydrothermal and green method | methylene blue (MB) | 9 | 5 mg/L | 0.05 g | 120 min | visible-light | 94% | Faraji et al. (2021) |
5 | GO/NiFe2O4/TiO2 | Length: 1.65 μm diameter: 60–120 nm | TiO2 NRAs: hydrothermal | unsymmetrical dimethylhydrazine (UDMH) | 9 | 20 mg/L | – | 90 min | visible light | 73.1% | Lu et al. (2021) |
NiFe2O4/TiO2 NRAs: dipping and annealing | |||||||||||
GO : modified Hummers' method | |||||||||||
6 | NiFe2O4 | 62.2–9.28 μm | modified green sol–gel route | IC dye and Phenol | 3 | 20 ppm | 40 mg | 120 min | Sunlight irradiation | – | Nadumane et al. (2019) |
NiFe2O4: Mg2 + | 0.46–8.33 μm | ||||||||||
7 | Cysteine modified Graphene oxide@nickelferrite@titanium dioxide | – | – | chlorpyrifos (CP) | 7 | 10 mg/L | 2 g/L | 1 h | visible light irradiation | 99.5% | Anirudhan et al. (2021) |
8 | Pectin- NiFe2O4 | 15–20 nm | hydrothermal | Methylene blue & Remazol Black 5 | 2.5 | 0.05 mM | 0.5 g/L | Methylene blue: 35 min | visible light | Methylene blue: 99.57% | Gupta et al. (2020) |
Remazol Black 5: 30 min | Remazol Black 5: 99.68% | ||||||||||
9 | NiFe2O4/ZnO:ZnO | : 48–52 nm | solidification and calcination methods | Coomassie blue G-250 dye | 3 | – | 0.1 g | 60 min | Visible and UV light | – | Yeganeh et al. (2020) |
NiFe2O4 | 25–31 nm | ||||||||||
10 | PANI/Ag3PO4/NiFe2O4 | Precipitation hydrothermal method | Rhodamine B (RhB) and methyl orange (MO) dyes | 6.8 | Optimum initial concentration of RhB dye: 10 mg/L | 1 g/L | 30 min | visible-light | RhB: 100% | Chen et al. (2019a) | |
MO: 94.97% | |||||||||||
11 | NiFe2O4 | 155–185 nm | solvothermal process | Methylene Blue (MB) | 7 | 0.03 g/L | 0.2 g/L | 50 min | UV | 98.5% | Guo & Wang (2019) |
12 | NiFe2O4@ ZnO | 35–45 nm | green sol–gel method | blue 129 dye and reactive blue 21 dye | – | 2 mg/L | 0.05 g for DB129 and 0.07 g for RB21 | 60 min | visible light | blue 129 dye: 98% | Moradi et al. (2018) |
reactive blue 21 dye: 96% | |||||||||||
13 | NiAlxFe2 − xO4 (x = 0–0.7) | 19–38 nm | sol–gel auto-combustion method | rose bengal (RB) dye | 8 | 5 ppm/100 mL | 40 mg/100 ml | 150 min | visible light | 99.8% | Naik et al. (2018) |
14 | MWCNTs-CuNiFe2O4 | 2–14 nm | Co-precipitation | Ampicillin (AMP) | 5 | 25 mg/L | 0.5 g/L | 60 min | UV | 100% | Al-Musawi et al. (2021) |
15 | CdS nanorods/NiFe2O4/NaX zeolite: (NiFe2O4) | 15 nm | simple ultrasound-assisted solvothermal method | Methylene Blue (MB), Eriochrome Black T (EBT), Rhodamine B (RhB) and Methyl Orange (MO) | _ | 25 mg/L | 50 mg | 60 min | Ultrasonic | MB: 100% | Sadeghi et al. (2020) |
RhB: 97.4% | |||||||||||
EBT: 90% | |||||||||||
MO: 85.3% | |||||||||||
16 | Z-scheme APO/MOF/NFO | – | precipitation method | Rhodamine B (RhB) | _ | 5 mg/L | 0.4 g/L | _ | visible-light irradiation | _ | Zhou et al. (2018) |
17 | NiFe2O4/T/GOx | – | solvothermal method | Indigo Carmine (IC) | 6.5 | 10 mg/L | _ | 90 min | Bio-Fenton process & UV lamp | Bio-Fenton process: 37.6% | Atacan et al. (2019) |
UV lamp: 98.6% | |||||||||||
18 | NiFe2O4 | 20–25 nm | _ | Methylene Blue (MB) | 7.81 | 20 mg/L | 22.35 mg | 67 min | UV light irradiation | 95.8% | Kazemi et al. (2018) |
19 | NiFe2O4@GO | 7.76 nm | solution combustion synthesis route | Methylene Blue (MB) | 10 | 0.04 mM | 0.5 g/L | 120 min | UV light irradiation | _ | Bayantong et al. (2021) |
20 | NiFe2O4-rice husk char (RHC) | – | simple soft chemical way | Methylene Blue (MB) | 2 | 10 mg/L | _ | _ | Visible-Light Irradiation | _ | Han et al. (2018) |
21 | NiFe2O4- | 10 nm | Hydrothermal method | Rhodamine B (RhB) | 3 | 10 mg/L | 0.2 g/L | 30 min | UV | _ | Liu et al. (2012) |
22 | NiFe2O4 & NiFe-CNT | one-step hydrothermal treatment | sulfamethoxazole (SMX) | 5 | 5 ppm | 0.025 g/L | 2 h | ultraviolet (UV)-A & visible light | 100% | Nawaz et al. (2020) | |
23 | NiFe2O4 | Co-precipitation method | Irgalite violet dye | 3 | 400 ppm | 0.2 g | 60 min | sunlight | 99% | Vijay et al. (2019) | |
24 | NiFe2O4/C yolk-shell- | 200–400 nm | hydrothermal deposition method | tetracycline hydrochloride (TC) | 7.5 | _ | 0.3 g/L | 60 min | visible light irradiation | 97.25% | Chen et al. (2019b) |
25 | Chitosan-Ascorbic Acid@NiFe2O4 (CTAS@NIFE)- | 5.15 nm | chemical co-precipitation method | malachite green (MG) | 8 | 70 mg/L | _ | 90 min | visible light irradiation coupled with ultrasonic waves | 99% | Hasan et al. (2020) |
26 | TiO2−x/NiFe2O4 | – | Consecutive sol–gel processes | ibuprofen (IBP) | 6 | 10 mg/L | 0.7 g/L | 100 min | ultrasonic irradiation | 96.70% | Wu (2020) |
27 | NiFe2O4: | 10–40 nm | solution combustion method | Congo red | 5 | 100 mg/L | _ | 60 min | Visible light | 96.80% | Hariani et al. (2021) |
28 | NiFe2O4–SQD (NF–SQDs) | 54.37 nm | hydrothermal synthesis | tetracycline (TC) | _ | 40 mg/L | 15 mg | 70 min | sunlight irradiation | 98% | Babu et al. (2021) |
29 | MWCNT–CuNiFe2O4 | – | Co-precipitation | acid blue 113 dye | 5 | 50 mg/L | 0.6 g/L | 30 min | UV | 100% | Al-Musawi et al. (2022) |
30 | NiFe2O4/MWCNTs/ZnO | – | hydrothermal and the co-precipitation methods | Methylene Blue (MB) dye | 11.5 | 20 mg/L | 1 g/L | 300 min | visible light | 73.02% | Hezam et al. (2020) |
31 | (NiFe2O4-SiO2), (NiFe2O4-TiO2), (NiFe2O4-SiO2-TiO2) and TiO2 | – | Co-precipitation and sol–gel methods | Cr(VI) | 2 | _ | 200 mg | TiO2: 240 min | UV irradiation | TiO2: 96.7% | Ojemaye et al. (2017) |
(NiFe2O4-SiO2-TiO2): 300 min | (NiFe2O4-SiO2-TiO2): 96.50% | ||||||||||
(NiFe2O4-TiO2): 300 min | (NiFe2O4-TiO2): 60% |
According to the results extracted in the previous studies and investigated in this study, the optimal pH was mentioned in different ranges, because the types of pollutant and their surface charges were different. Considering that photocatalytic processes are usually carried out on the surface of catalysts, the surface electric charge of different catalysts may be positive or negative depending on the catalyst components and surface functional groups. In photocatalytic processes, pHzpc plays a significant role, because in pHzpc, the positive and negative electric charges on the catalyst surface are balanced. At pH > pHzpc, the dominant electrical charge on the catalyst surface is negative due to excess OH ions, and at pH < pHzpc, the dominant electrical charge on the catalyst surface becomes positive due to H+ ions (Moein et al. 2020; Mohammadi et al. 2022).
For example, the results of Bayantong et al.'s study showed that the decolorization of methylene blue by NiFe2O4@GO photocatalytic nanocomposite is enhanced under alkaline conditions because methylene blue is a cationic organic dye (Bayantong et al. 2021). On the other hand, NiFe2O4@GO nanocomposite has a negative charge when pH > pHzpc (Perreault et al. 2015). As a result, the surface charge of the nanocomposite and the dye are opposite in alkaline conditions, which causes the dye to adsorb on the surface of the nanocomposite and increase its degradation (Bayantong et al. 2021).
The results of another study conducted by Nadumane et al. showed that the highest efficiency for phenol occurred at pH = 3. Their reasoning was that in addition to OH° radicals produced by photofenton activities, at lower pH, hydrogen ions react to produce OH° radicals to degrade phenol. But in alkaline conditions, the hydroxyl ions in the solution are highly concentrated, which makes the sunlight not reach the surface of the photocatalyst, and as a result, the rate of decomposition decreases (Nadumane et al. 2019).
Influence of initial pollutants concentration on photocatalytic activity of NiFe2O4-based nanocomposites
The initial concentration of the desired pollutant in the water environment is one of the important parameters that affects the removal efficiency in the photocatalytic purification process (Darvishi Cheshmeh Soltani et al. 2016). In most of the studies that investigated the effect of the initial concentration of the environmental pollutants, they concluded that the efficiency of the photocatalytic degradation process decreases with the increase of the initial concentration of the pollutant.
The reason for the decrease in efficiency with the increase in the initial concentration of the target pollutant is that at lower concentrations there is more surface on the catalyst to adsorb the pollutant. But with the increase of pollutant concentration, more molecules are adsorbed on the active surface groups of catalyst nanocomposites and therefore reduce the available reaction sites (Wang et al. 2012; Khodadadi et al. 2020).
On the other hand, the concentration of free radicals produced in all solutions is equal to the different concentration of the pollutant; therefore, a solution with a low pollutant concentration with the same amount of hydroxyl radical will have a higher decomposition rate than a solution with a higher concentration (Wang et al. 2012).
Influence of catalyst dose on photocatalytic activity of NiFe2O4-based nanocomposites
The optimal photocatalytic nanocomposites dose in aqueous solution is one of the most important parameters on the efficiency of photocatalytic processes (Kamani et al. 2021). The results of the investigated studies showed that at low doses of photocatalyst, the degradation efficiency increases with the increase of the catalyst dose. The reason is the increase in the number of active sites on the surface of the nanocatalyst. However, very high doses of photocatalyst increase the turbidity in the solution. This turbidity prevents the penetration of light into the solution and increases the scattering of light in the solution, which ultimately leads to a weak light reaction and a decrease in the efficiency of the degradation of impurities (Pei & Leung 2013).
However, in general, the increase or decrease of the performance of the photocatalyst process depends on the dosage range of the nanocatalyst. If the selected range of catalyst dosage is low enough not to cause additional turbidity, the performance of photocatalytic degradation will increase with increasing nanocatalyst dosage. But if the dosage range of the selected catalyst is wide and includes high dosages that cause turbidity, usually by increasing the catalyst dosage beyond a certain limit, the degradation performance decreases due to the prevention of proper radiation and lack of light penetration (Kamranifar et al. 2019; Derakhshani et al. 2022).
Influence of contact time on photocatalytic activity of NiFe2O4-based nanocomposites
Another parameter that affects the photocatalytic decomposition of pollutants is the appropriate contact time of the pollutant with the nanocatalyst, which has been investigated in some studies. The results of these studies showed that in the early stages of degradation, the amount of contact between the nanocatalyst and the pollutant is higher and the number of holes on the surface of the nanocatalyst is higher. With the gradual occupation of these holes and places by the pollutant, the amount of destruction decreases compared to the initial stages, and after a certain period of time, the amount of destruction reaches a constant value and may decrease after that (Oskoei et al. 2016). In a study conducted by Kazemi et al., the effect of time on the decomposition of methylene blue was investigated for 30–150 min. The results of their study showed that the rate of photocatalytic degradation of methylene dye increased with increasing contact time, but after 60 min, the degradation was almost constant (Kazemi et al. 2018).
As is clear from Table 3, in some of the reviewed studies, other parameters have been investigated in addition to the parameters in Table 2, some of which we will explain below:
Other monitored parameters . | Reference . |
---|---|
Antibacterial performance of Ag–d-NZF: Ag–doped Ni0.5Zn0.5Fe2O4 had higher antibacterial activity on E. coli than S. aureus strains. | Mustafa & Oladipo (2021) |
Effect of interference and reusability of Ag–d-NZF: The lowest degradation was recorded in the presence of NO3 due to its quenching effect. The degradation efficiency of Ag-d-NZF decreased to ∼71% in the second reuse step and decreased to ∼57% in the fifth reuse step. | |
Stability of the photocatalyst: There was no significant decrease in photocatalyst activity for six cycles, and the photocatalyst could be reused for more than six photocatalytic cycles. | Bagherzadeh et al. (2018) |
Effect of NiFe2O4 content in nanocomposite: The highest photocatalytic activity for methylene blue (MB) degradation was for Z/NFO-30 sample compared to Z/NFO-10, Z/NFO-50 and Z/NFO-70. | Faraji et al. (2021) |
Effect of different catalysts on the degradation of methylene blue (MB): Among ZIF-8, NiFe2O4 and Z/NFO-30 composites, Z/NFO-30 nanocomposite demonstrated the highest methylene blue (MB) removal efficiency (94% after 120 min). | |
Regeneration and reusability of the photocatalyst: The results showed that the photocatalysts are stable and usable for several times. | |
Effect of H2O2 in photocatalysis process: The degradation rate gradually increased up to 6 mM for IC dye and then decreased with increasing dose. For phenol, the rate of degradation increased up to 5 mM and then decreased with increasing dose | Nadumane et al. (2019) |
Investigating the stability and reuse of nanocomposites: The irradiation-separation-washing process can be repeated several times, while maintaining the high photocatalytic activity of nanocomposites for IC dye and phenol degradation. | |
The influence of H2C2O4 concentration: The results showed that the rate of methylene blue decolorization increases with increasing the dose of H2C2O4 from 0 to 0.06 g/L. | Guo & Wang (2019) |
The effect of H2O2 dosage on the MB degradation: The results showed that the degradation of methylene blue increased with increasing the dose of H2O2 from 0 to 5 mM and the degradation rate was over 98.5%. | |
Effect of visible light irradiation on removal of dyes: The results showed that no degradation was observed in the presence of visible light and without the addition of a catalyst. Also, dye degradation in the presence of magnetic nanocomposite in dark conditions was 39% for DB129 and 25% for RB21. But the dye degradation in the presence of visible light and magnetic nanocomposite for DB129 and RB21 was above 96% in 60 min. | Moradi et al. (2018) |
Reuse of the photocatalyst: The results of this study showed that the photocatalytic activity of magnetic nanocomposite in color degradation does not decrease after five reuses. As a result, this catalyst is economical and stable in removing pollutants. | |
The effect of UV light intensity: From the results of this study, it can be seen that the degradation rate of ampicillin increases with the increase of light intensity from 8 to 36 W. | Al-Musawi et al. (2021) |
Stability study: To evaluate the recyclability of the photocatalyst, ampicillin photodegradation experiments were performed in eight consecutive reaction cycles under the same conditions. The results showed that the degradation rate of ampicillin decreased slowly from 100% in the third round to 93.72% in the eighth round. | |
H2O2 volume: The rate constant initially increased with increasing volume of H2O2 up to 4 mL and then decreased. | Han et al. (2018) |
Cycle performance: The degradation efficiency was unchanged after five recycling cycles of nanocomposites. | |
Effects of the initial oxalic C(H2C2O4) concentration: By increasing the concentration of oxalic acid from 0.1 to 1.0 mM, the decomposition rate of Rhodamine B increased, and then at concentrations higher than 1.0 mM, the decomposition rate remained constant. | Liu et al. (2012) |
Stability and reuse of catalyst: The results showed that the used catalyst is stable and recoverable because the decolorization ratio in all seven steps was more than 90.0%. | |
H2O2 concentration: The optimal concentration of H2O2 for the degradation of sulfamethoxazole was found to be 1 μL/mL. At concentrations higher than 1 μL/mL, incomplete removal of SMX from the reaction solution occurred. | Nawaz et al. (2020) |
Reusability and stability of the NiFe-CNT composite: The results showed that the degradation efficiency by the NiFe-CNT composite decreased by approximately 20% after five cycles. | |
The effect of H2O2 concentration on the tetracycline hydrochloride (TC) degradation: The degradation efficiency of TC increased greatly as the initial volume of H2O2 increased from 0 to 0.1 mL, then decreased with further addition to 1 mL. | Chen et al. (2019b) |
Sonophotocatalysis with Variable Ultrasonic Power Intensities: The results showed that the percentage of malachite green (MG) degradation increased with increasing density of ultrasonic power. | Hasan et al. (2020) |
Influence of ultrasonic power and frequency: In this study, the degradation percentage of ibuprofen (IBP) increased with increasing ultrasonic power. | Wu (2020) |
Influence of persulfate on ibuprofen (IBP) mineralization: The addition of PS to the sonocatalytic system increased the removal efficiency of ibuprofen (IBP) and the detoxification efficiency. | |
Reusability and stability evaluation: In this study, the high recyclability of the sonocatalyst was reported, because the removal percentage of ibuprofen was 96.7% in the first use, and it slightly decreased in the sixth use and reached 95.8%. | |
The effect of the intensity of UV light: The results showed that by increasing UV intensity from 8 to 36 W, acid blue 113 dye degradation efficiency at a reaction time of 25 min increased from 80.59 to 100%. | Al-Musawi et al. (2022) |
The effect of US frequency: In this study by increasing the frequency from 20 to 35 kHz, the acid blue 113 dye degradation efficiency at a reaction time of 30 min increased from 86.49 to 99.06%. | |
Regenerability and reusability study: The results showed that the photocatalyst materials can be regenerated for reuse and NiFe2O4-SiO2-TiO2 showed better reusability than NiFe2O4-TiO2. | Ojemaye et al. (2017) |
Other monitored parameters . | Reference . |
---|---|
Antibacterial performance of Ag–d-NZF: Ag–doped Ni0.5Zn0.5Fe2O4 had higher antibacterial activity on E. coli than S. aureus strains. | Mustafa & Oladipo (2021) |
Effect of interference and reusability of Ag–d-NZF: The lowest degradation was recorded in the presence of NO3 due to its quenching effect. The degradation efficiency of Ag-d-NZF decreased to ∼71% in the second reuse step and decreased to ∼57% in the fifth reuse step. | |
Stability of the photocatalyst: There was no significant decrease in photocatalyst activity for six cycles, and the photocatalyst could be reused for more than six photocatalytic cycles. | Bagherzadeh et al. (2018) |
Effect of NiFe2O4 content in nanocomposite: The highest photocatalytic activity for methylene blue (MB) degradation was for Z/NFO-30 sample compared to Z/NFO-10, Z/NFO-50 and Z/NFO-70. | Faraji et al. (2021) |
Effect of different catalysts on the degradation of methylene blue (MB): Among ZIF-8, NiFe2O4 and Z/NFO-30 composites, Z/NFO-30 nanocomposite demonstrated the highest methylene blue (MB) removal efficiency (94% after 120 min). | |
Regeneration and reusability of the photocatalyst: The results showed that the photocatalysts are stable and usable for several times. | |
Effect of H2O2 in photocatalysis process: The degradation rate gradually increased up to 6 mM for IC dye and then decreased with increasing dose. For phenol, the rate of degradation increased up to 5 mM and then decreased with increasing dose | Nadumane et al. (2019) |
Investigating the stability and reuse of nanocomposites: The irradiation-separation-washing process can be repeated several times, while maintaining the high photocatalytic activity of nanocomposites for IC dye and phenol degradation. | |
The influence of H2C2O4 concentration: The results showed that the rate of methylene blue decolorization increases with increasing the dose of H2C2O4 from 0 to 0.06 g/L. | Guo & Wang (2019) |
The effect of H2O2 dosage on the MB degradation: The results showed that the degradation of methylene blue increased with increasing the dose of H2O2 from 0 to 5 mM and the degradation rate was over 98.5%. | |
Effect of visible light irradiation on removal of dyes: The results showed that no degradation was observed in the presence of visible light and without the addition of a catalyst. Also, dye degradation in the presence of magnetic nanocomposite in dark conditions was 39% for DB129 and 25% for RB21. But the dye degradation in the presence of visible light and magnetic nanocomposite for DB129 and RB21 was above 96% in 60 min. | Moradi et al. (2018) |
Reuse of the photocatalyst: The results of this study showed that the photocatalytic activity of magnetic nanocomposite in color degradation does not decrease after five reuses. As a result, this catalyst is economical and stable in removing pollutants. | |
The effect of UV light intensity: From the results of this study, it can be seen that the degradation rate of ampicillin increases with the increase of light intensity from 8 to 36 W. | Al-Musawi et al. (2021) |
Stability study: To evaluate the recyclability of the photocatalyst, ampicillin photodegradation experiments were performed in eight consecutive reaction cycles under the same conditions. The results showed that the degradation rate of ampicillin decreased slowly from 100% in the third round to 93.72% in the eighth round. | |
H2O2 volume: The rate constant initially increased with increasing volume of H2O2 up to 4 mL and then decreased. | Han et al. (2018) |
Cycle performance: The degradation efficiency was unchanged after five recycling cycles of nanocomposites. | |
Effects of the initial oxalic C(H2C2O4) concentration: By increasing the concentration of oxalic acid from 0.1 to 1.0 mM, the decomposition rate of Rhodamine B increased, and then at concentrations higher than 1.0 mM, the decomposition rate remained constant. | Liu et al. (2012) |
Stability and reuse of catalyst: The results showed that the used catalyst is stable and recoverable because the decolorization ratio in all seven steps was more than 90.0%. | |
H2O2 concentration: The optimal concentration of H2O2 for the degradation of sulfamethoxazole was found to be 1 μL/mL. At concentrations higher than 1 μL/mL, incomplete removal of SMX from the reaction solution occurred. | Nawaz et al. (2020) |
Reusability and stability of the NiFe-CNT composite: The results showed that the degradation efficiency by the NiFe-CNT composite decreased by approximately 20% after five cycles. | |
The effect of H2O2 concentration on the tetracycline hydrochloride (TC) degradation: The degradation efficiency of TC increased greatly as the initial volume of H2O2 increased from 0 to 0.1 mL, then decreased with further addition to 1 mL. | Chen et al. (2019b) |
Sonophotocatalysis with Variable Ultrasonic Power Intensities: The results showed that the percentage of malachite green (MG) degradation increased with increasing density of ultrasonic power. | Hasan et al. (2020) |
Influence of ultrasonic power and frequency: In this study, the degradation percentage of ibuprofen (IBP) increased with increasing ultrasonic power. | Wu (2020) |
Influence of persulfate on ibuprofen (IBP) mineralization: The addition of PS to the sonocatalytic system increased the removal efficiency of ibuprofen (IBP) and the detoxification efficiency. | |
Reusability and stability evaluation: In this study, the high recyclability of the sonocatalyst was reported, because the removal percentage of ibuprofen was 96.7% in the first use, and it slightly decreased in the sixth use and reached 95.8%. | |
The effect of the intensity of UV light: The results showed that by increasing UV intensity from 8 to 36 W, acid blue 113 dye degradation efficiency at a reaction time of 25 min increased from 80.59 to 100%. | Al-Musawi et al. (2022) |
The effect of US frequency: In this study by increasing the frequency from 20 to 35 kHz, the acid blue 113 dye degradation efficiency at a reaction time of 30 min increased from 86.49 to 99.06%. | |
Regenerability and reusability study: The results showed that the photocatalyst materials can be regenerated for reuse and NiFe2O4-SiO2-TiO2 showed better reusability than NiFe2O4-TiO2. | Ojemaye et al. (2017) |
Antibacterial performance of NiFe2O4-based nanocomposites
Antibacterial agents cause rapid recovery of bacterial infections and also reduce the possibility of bacterial resistance to drugs, which is why antibacterial agents are widely used in the medical field (Hanif et al. 2019). Mustafa et al. investigated the photocatalytic degradation of metronidazole by Ag-doped Ni0.5Zn0.5Fe2O4 nanocomposites and also the antibacterial activity of Ag-d-NZF against Escherichia coli and Staphylococcus aureus. The results showed that Ag-d-NZF has more antibacterial activity on E. coli than Staphylococcus aureus strains, which is probably due to changes in the structure and composition of the cell membrane (Mustafa & Oladipo 2021).
Stability and reuse of NiFe2O4-based nanocomposites
For the use of synthesized nanocatalysts in industry, it is important to determine the reusability of consumed nanocatalysts in order to reduce costs and availability of nanocatalysts for photocatalytic processes and environmental safety (Ojemaye et al. 2017).
Moradi et al. investigated the reuse of NiFe2O4@ZnO nanocatalysts. They concluded that the photocatalytic activity of NiFe2O4@ZnO nanocomposite does not decrease in color degradation after five reuses. As a result, this catalyst is very stable and cost-effective in removal pollutants (Moradi et al. 2018). Nawaz et al. recycled the NiFe-CNT nanocomposite five times in order to investigate its stability and recyclability. The results showed that almost all the functional groups were present in the recycled photocatalytic materials and all the composite components were intact and stable (Nawaz et al. 2020).
Influence of H2O2 addition on pollutants degradation by NiFe2O4-based nanocomposites
H2O2 is used as an inorganic oxidant to increase the rate of photocatalytic reactions. Because hydrogen peroxide requires less energy than molecular oxygen to produce hydroxyl radicals, hydrogen peroxide is a better electron acceptor (Kim et al. 2013; Derakhshani et al. 2022).
The effect of H2O2 concentration on the degradation of sulfamethoxazole (SMX) was investigated by Nawaz et al. Based on the results obtained from their study, the optimal concentration of H2O2 for the degradation of SMX was found to be 1 μL/mL. At concentrations higher than 1 μL/mL, incomplete removal of SMX from the reaction solution occurred (Nawaz et al. 2020).
Chen et al. investigated the effect of H2O2 concentration on the degradation of TC. They concluded that the degradation efficiency of TC increased sharply as the initial volume of H2O2 increased from 0 to 0.1 mL, then decreased upon further addition to 1 mL.
The effect of UV light intensity on photocatalytic activity of NiFe2O4-based nanocomposites
In a study, Al-Musawi et al. investigated the effect of UV light intensity on the degradation efficiency of ampicillin (AMP) by MWCNTs-CuNiFe2O4 nanocomposites. From the results of this study, it can be seen that the degradation rate of ampicillin increases with the increase of light intensity from 8 to 36 W. Increasing the degradation rate of ampicillin may be related to the production of more protons, which are required to transfer electrons from the valence band to the conduction band to production more reactive species (Al-Musawi et al. 2021).
Other parameters investigated in studies for the photocatalytic degradation of pollutants by NiFe2O4-based are described in Table 3. In addition, advantages and disadvantages of NiFe2O4-based nanocomposites synthesis methods are shown in Table 4.
Synthesis methods . | Advantages . | Disadvantages . |
---|---|---|
Hydrothermal method (Basavegowda & Baek 2021) |
|
|
Co-precipitation method (Entwistle et al. 2022) |
|
|
Green method (Pal et al. 2022, Gholami et al. 2023) |
|
|
Sol–gel method (Bokov et al. 2021) |
|
|
Synthesis methods . | Advantages . | Disadvantages . |
---|---|---|
Hydrothermal method (Basavegowda & Baek 2021) |
|
|
Co-precipitation method (Entwistle et al. 2022) |
|
|
Green method (Pal et al. 2022, Gholami et al. 2023) |
|
|
Sol–gel method (Bokov et al. 2021) |
|
|
Challenges and future prospective
Advancement in the technology sector is increasing day by day due to the advancement of nanotechnology. It is expected that the use of nanostructures and nanomaterials will increase rapidly in the coming years, especially in water and wastewater treatment and removal of pollutants from the environment. Inadequate water resources and deterioration of their quality cause water scarcity, which adversely affects living organisms and the environment. The development of technological advancements, especially in the field of nanotechnology, may help to overcome these effects. Some nanomaterials are very toxic to humans and the environment. If these nanomaterials are used in water purification and their residues remain in the water, it leads to various poisonings. Therefore, researchers should focus on new techniques to standardize the measurement of hazardous effects of nanomaterials on human health.
The synthesis of nickel-based nanocomposites has often been associated with various challenges. These may mostly involve the problem of reduction of Ni(II) to Ni(0) at room temperature (Hossain et al. 2018). Only a few investigations are reported using nickel-based nanocomposites as adsorbents or photo catalysts in wastewater treatment. Plant extracts containing compounds that serve as reducing and capping agents in stabilizing the nanoparticles of Ni and NiO are to be identified in the available flora. Therefore green synthesis of nickel-based nanocomposites is a promising area for future research. Microbial mediated synthesis of nano-Ni and NiO are less investigated, and this is another vital aspect for research (Verma et al. 2021).
Photocatalytic decomposition of pollutants using nickel-based nanocomposites mainly depends on the type of pollutants, solution pH and concentration, catalysts and their composition, catalyst loading, solvent types, temperature and light intensity. While the advantages of using nickel nanocomposites as catalysts are emphasized, the disadvantages are not listed. It is hoped that in the future more emphasis will be placed on the use of nickel nanocomposites on a laboratory scale in the removal of pollutants. Also, the problems related to the residue of these nanocomposites in water, including their toxic properties on humans, should be investigated.
CONCLUSION
The comprehensive systematic review highlighted the photocatalytic degradation of pollutants using NiFe2O4-based nanocomposites in aqueous solution. In all the articles, the topic of photodegradation of pollutants using NiFe2O4-based nanocomposites was studied. The photocatalytic activity of the synthesized nanocomposite photocatalysts for degradation of various pollutants was also studied. The available literature reviewed here has shown an increasing interest in photocatalytic processes for the removal of pollutants by NiFe2O4-based nanocomposites from aqueous media in recent years. The most degraded pollutants in the studied research works were methylene blue dye and Rhodamine B with degradation efficiencies of 100%. Considering this variety, it can be mentioned that the photocatalytic process using NiFe2O4-based nanocomposites has been successful in breaking down aqueous solution pollutants.
ACKNOWLEDGEMENT
This article is part of the PhD thesis accepted in Birjand University of Medical Sciences, Iran coded 456905 and the side project accepted and financially supported by Research deputy of BUMS coded 2039. The authors are also grateful to the staff of the Medical Toxicology and Drug Abuse Research Center (MTDRC) for assisting in the analyses.
ETHICAL APPROVAL
This article does not contain any studies with human participants or animals performed by any of the authors.
CONSENT TO PUBLISH
All the authors mentioned in the manuscript have agreed to authorship, read, and approved the manuscript, and given consent for submission and subsequent publication of the manuscript.
AUTHORS CONTRIBUTIONS
All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by E.D. and A.N. The first draft of the manuscript was written by E.D. and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
FUNDING
This article is part of the PhD thesis accepted in Birjand University of Medical Sciences, Iran coded 456905 and the side project accepted and financially support in Research deputy of BUMS coded 6022.
DATA AVAILABILITY STATEMENT
All relevant data are included in the paper or its Supplementary Information.
CONFLICT OF INTEREST
The authors declare there is no conflict.