Advances on modification of photocatalyst for degradation/removal of organic pollutants from water

Abstract

Modification strategies such as surface doping, surface defect engineering, surface sensitization and heterojunction have proved to be highly effective in improving the performance of a photocatalyst towards the degradation removal of organic pollutants from water. Photocatalysts such as N-doped TiO₂ nanotubes and S-doped TiO₂ nanoparticles prepared via surface doping have been described to displayed higher photocatalytic degradation of methyl orange and malachite green compared to unmodified TiO₂ nanoparticles. Moreover, AgI/CdS binary composite fabricated via type-II conventional heterojunction strategy has been recounted in obtaining 91 and 94.5 % removal of tetracycline hydrochloride and methyl orange removal from water. Whereas, GQD/ZnO nanowires photocatalyst developed using a direct z-scheme heterostructure strategy has been investigated to yield three times comparably higher degradation of methylene blue than using pure ZnO nanowires. Similar outcomes have been reported with photocatalysts prepared using surface defect engineering and surface sensitization strategies. In comparison to previous studies, this review accentuates the recent advances on the various modification strategies for enhancing photocatalytic performance in removing organic pollutants from wastewater. While recounting the challenges and direction of future studies in palliating these challenges.