| Autor: |
Du, Xiya, Song, Song, Wang, Yating, Jin, Wenfeng, Ding, Tong, Tian, Ye, Li, Xingang |
| Zdroj: |
Catalysis Science & Technology; 2021, Vol. 11 Issue: 8 p2734-2744, 11p |
| Abstrakt: |
Constructing step-scheme (S-scheme) heterojunctions is one of the efficient strategies to enhance photocatalytic processes, but unfortunately their synthesis requires complex procedures. Here, we develop a facile methodology for one-pot synthesis of defect-engineered S-scheme WO3/g-C3N4heterojunctions. The as-synthesized sample (15.0WCN) exhibits a remarkable photocatalytic hydrogen generation rate (1034 μmol h−1g−1), which is 1.7 and 4.5 times higher than that of normal S-scheme WO3/g-C3N4heterojunctions (15.0W + CN) and pure g-C3N4, respectively. We discover that surface oxygen vacancies can improve the separation efficiency of photogenerated carriers by acting as a mediator between the valence band of g-C3N4and the conduction band of WO3, while bulk oxygen vacancies mainly enhance visible light absorption through narrowing the band gap in the S-scheme system. In addition, our studies show that surface oxygen vacancies are more effective than bulk ones in S-scheme heterojunctions for photocatalytic hydrogen production. This work affords a new insight into coupling strategies of defect-engineering and S-scheme heterojunctions, which is helpful for designing other efficient photocatalytic systems. |
| Databáze: |
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