A Twin S-Scheme Artificial Photosynthetic System with Self-Assembled Heterojunctions Yields Superior Photocatalytic Hydrogen Evolution Rate

作者：Ruan, Xiaowen; Huang, Chengxiang; Cheng, Hui; Zhang, Zhiquan; Cui, Yi; Li, Zhiyun; Xie, Tengfeng; Ba, Kaikai; Zhang, Haiyan; Zhang, Lei; Zhao, Xiao; Leng, Jing; Jin, Shengye; Zhang, Wei; Zheng, Weitao; Ravi, Sai Kishore^*; Jiang, Zhifeng^*; Cui, Xiaoqiang^*; Yu, Jiaguo

来源：Advanced Materials, 2023, 35(6).

DOI：10.1002/adma.202209141

• artificial photosynthetic system
• band alignment
• charge transfer
• hydrogen evolution
• photocatalyst
• twin S-scheme

Designing heterojunction photocatalysts imitating natural photosynthetic systems has been a promising approach for photocatalytic hydrogen generation. However, in the traditional Z-Scheme artificial photosynthetic systems, the poor charge separation, and rapid recombination of photogenerated carriers remain a huge bottleneck. To rationally design S-Scheme (i.e., Step scheme) heterojunctions by avoiding the futile charge transport routes is therefore seen as an attractive approach to achieving high hydrogen evolution rates. Herein, a twin S-scheme heterojunction is proposed involving graphitic C3N4 nanosheets self-assembled with hydrogen-doped rutile TiO2 nanorods and anatase TiO2 nanoparticles. This catalyst shows an excellent photocatalytic hydrogen evolution rate of 62.37 mmol g(-1) h(-1) and high apparent quantum efficiency of 45.9% at 365 nm. The significant enhancement of photocatalytic performance is attributed to the efficient charge separation and transfer induced by the unique twin S-scheme structure. The charge transfer route in the twin S-scheme is confirmed by in situ X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) spin-trapping tests. Femtosecond transient absorption (fs-TA) spectroscopy, transient-state surface photovoltage (TPV), and other ex situ characterizations further corroborate the efficient charge transport across the catalyst interface. This work offers a new perspective on constructing artificial photosynthetic systems with S-scheme heterojunctions to enhance photocatalytic performance.

• 单位
  江苏大学; 吉林大学; 中国科学院