Visible-light assisted methylene blue (MB) removal by novel TiO₂/adsorbent nanocomposites

In present work, visible light sensitive TiO₂/adsorbent nanocomposites (TNC) were prepared via a facile wet chemical method. Three types of adsorbents including zeolites (F-9, HSZ-690 and HSZ-930), mesoporous silica (MPS-2.7 and 4) and activated carbon, were used as the porous substrates for nanocomposites. Visible light sensitivity was incorporated to TNCs by nitrogen doping of TiO₂, which is obtained through the addition of a nitrogen precursor, triethylamine, within the same wet chemical procedure. The photocatalytic and adsorption ability of as-prepared TNC resultants were studied using solutions of methylene blue (MB) as a model pollutant. Synergistic interactions between adsorption and visible-light photocatalysis were observed, as under the assistance of visible-light irradiation all TNCs achieved higher MB removal rates than those by adsorption process alone. The better performance of the as-prepared N-doped TNC reveals its potential to be used for cost effective solar photocatalytic degradation of dissolved organic compounds.