Influence of anatase and rutile phase in TiO₂ upon the photocatalytic degradation of methylene blue under solar irradiation in presence of activated carbon

The influence of activated carbon (AC) on the photocatalytic activity of different crystalline TiO₂ phases was verified in the photocatalytic degradation of methylene blue under UV and solar irradiation. The results showed a volcano trend with a maximum photoactivity for the crystalline phase ratio of anatase:rutile equal to 80:20 both under UV or solar irradiation. By contrast, in presence of AC the photocatalytic activity of the binary materials of TiO₂/AC followed an exponential trend, increasing as a function of the increase in anatase proportion in the TiO₂ framework. The increase in the photoactivity of the binary material TiO₂/AC relative to neat TiO₂ was up to 22 and about 17 times higher under UV and visible irradiation, respectively. The present results suggest that AC interacts more efficiently with anatase phase than with rutile phase.