Photocatalytic CO2 reduction using metal and nonmetal doped TiO2 and its mechanism

Photocatalysis based on semiconductors has recently sparked significant scientific interest due to its numerous applications in environmental beneficiaries and renewable energy generation. TiO2 reported in the literature is UV-active due to its larger band gap. Platinum (Pt) metal combined with titanium dioxide (TiO2) photocatalyst, is widely used as an effective photocatalyst for carbon dioxide hydrogenation. Therefore, this Review study aims to enhance the activity of photocatalysts, employing distinct modification strategies to decrease band gap and make the photocatalyst efficient in absorbing visible light range. This review summarises the photocatalytic mechanism, as well as numerous modification techniques, for changing UV light-active photocatalysts to visible light active as well as increasing visible light absorption. These modification techniques include variability via using various semiconducting materials as well as metal and nonmetal doping, sensitizer doping, a heterojunction formation as well as semiconductors coupling, co-catalyst loading, and defect formation.