Photocatalytic Applications in Wastewater Treatment

The problem of wastewater treatment is one of the issues where photocatalysis plays a major role. Some model molecules are used to mimic the most common water pollutants, and among these, dyes and phenols are the most commonly used. 

Supercritical (sc) C02 can be used as solvent to prepare N-doped and N,Zr-doped Ti02 materials [81] and the doping with N influences the crystallinity of the final 

N-doped titania demonstrated promising activity under visible light for the degradation of Rhodamine B in aqueous solutions [85], In thin-films of N-doped Ti02, the formation of nitride phases enhanced the catalytic properties of the film [86]. 

Mixed Ti-W oxides, after deposition of Pt, are active in the mineralization of toluene with sunlight excitation due to the low bandgap (2.7 eV) caused by the presence of both W and Pt in the anatase structure [87]. Vanadium was also used to prepare visible light active photocatalysts in dye degradation [88]. 

Cr- and N-doped titania showed improved activity under visible light in the degradation of methylene blue and isopropyl alcohol [89]. I-doped Ti02 showed better activity than Degussa P25 for methylene blue degradation. The sample composed of anatase and rutile showed better activity than that with only anatase [90] for phenol degradation [91]. 

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