C-H activation-derived polymer@TiO p-n heterojunction for photocatalytic hydrogen evolution

• Published in: Sustainable energy & fuels Vol. 5; no. 2; pp. 5166 - 5174
• Main Authors: Xing, Yu-Qin, Tan, Zhi-Rong, Cheng, Jing-Zhao, Shen, Zhao-Qi, Zhang, Yu-Jie, Chen, Long, Liu, Shi-Yong
• Format: Journal Article
• Published: 12.10.2021
• ISSN: 2398-4902
• DOI: 10.1039/d1se00970b

Semiconductor heterojunctions benefiting from efficient charge transfer and separation have been widely used in photocatalysis. Herein, heterojunctions based on polymeric and inorganic semiconductors, namely PyOT@TiO 2 , have been successfully constructed via in situ C-H activation polycondensation of the pyrene unit (Py-) and 3-(2-(2-ethoxyethoxy)ethoxy)thiophene unit (-OT) in the presence of titanium dioxide (TiO 2 ). The combination of the polymeric semiconductor PyOT with TiO 2 not only broadens the light response of TiO 2 , but also dramatically promotes the photo-generation exciton separation of PyOT. As a result, the optimized 50% PyOT@TiO 2 composite exhibited extensive visible light absorption (400-520 nm) and the highest photocatalytic hydrogen evolution rate using ascorbic acid (AA) as the sacrificial agent, which is approximately 135 and 21 times higher than those of single-components TiO 2 and PyOT, respectively. Mechanistic study by XPS, M-S plots and hydroxyl radical detection tests revealed the p-n heterojunction characteristics of PyOT@TiO 2 that contributed to the enhanced photocatalytic performance. Our work develops a promising strategy for the in situ construction of polymeric-inorganic soft-hard heterostructures via atom-economic C-H activation polymerization. Polymer@TiO 2 p-n heterojunction photocatalysts are successfully constructed via atom-economic in situ C-H activation polymerization.