Enhanced photocatalytic hydrogen evolution and CO2 to CH4 selectivity of Co3O4/Ti3+-TiO2 hollow S-scheme heterojunction via ZIF-67 self-template and Ti3+/Ov. (12th May 2023)

• Record Type: Journal Article
• Authors: Xiao, Guangsheng; Niu, Jingjing; Fu, Yueyue; Cao, Jun; Wang, Jingjing; Zheng, Yingying; Li, Chaorong; Pan, Jiaqi
• Is Part Of: International journal of hydrogen energy. Volume 48:Number 41(2023)
• Page Start: 15574
• Page End: 15585
• Publication Date: 2023-05-12
• Subjects: Photocatalytic hydrogen evolution -- CO2 photoreduction -- CH4 selectivity -- Ti3+/Ov -- S-scheme heterojunction; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2023.01.101
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The potential would be an important issue for enhancing photocatalytic HER and CO2 photoreduction selectivity. Herein, the Co3 O4 /Ti 3+ -TiO2 hollow S-scheme heterojunction is fabricated via continuous light modification-chemical-annealing-reduction method. Evaluated by photocatalytic performance, the as-prepared Co3 O4 /Ti 3+ -TiO2 hollow S-scheme heterojunction exhibits remarkable photocatalytic performance enhancement than single TiO2, including hydrogen evolution (∼396.16 μmol/g·h, ∼15 folds) and CO2 photoreduction (H2 /CH4 /CO: ∼20.32/80.57/9.85 μmol/g·h, ∼20 folds), and achieves CO2 photoreduction to CH4 selectivity enhancement, which can be mainly ascribed to the synergism of Ti 3+ /Ov and S-scheme heterojunction. There, Ti 3+ /Ov can not only increase the solar efficiency, but also decrease the energy barrier of H + and ∗CO photoreduction to enhance HER and CO2 to CH4 selectivity, including promote the H + diffusion and CO2 absorption. Additionally, the formed Co3 O4 /Ti 3+ -TiO2 S-scheme heterojunction can promote the photo-generated carrier separation/transportation. Also, the hollow 3D structure obtained by ZIF-67 self-template can increase solar efficiency and stability. Graphical abstract: Image 1 Highlights: Ti 3+ /Ov can decrease ∗CO photoreduction energy barrier to enhance CH4 selectivity. Ti 3+ /Ov with shallow donor level can increase carrier concentration. Heterojunction can promote carriers separation/transport via appropriate potential. Hollow 3D structure can increase interface heterojunction and stability. ZIF-67 self-template can decrease photocatalyst corrosion.