Biomimetic electron transport via multiredox shuttles from photosystem II to a photoelectrochemical cell for solar water splitting

• Published in: Energy & environmental science Vol. 10; no. 3; pp. 765 - 771
• Main Authors: Li, Zhen, Wang, Wangyin, Ding, Chunmei, Wang, Zhiliang, Liao, Shichao, Li, Can
• Format: Journal Article
• Language: English
• Published: 01.03.2017
• Subjects: Biomimetics; Direct power generation; Efficiency; Electrolytic cells; Electron transfer; Electron transport; Photosynthesis; Water splitting
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/c6ee03401b

A bio-hybrid system integrating photosystem II (PSII) with artificial photocatalysts is considered as a platform to understand the solar-to-chemical energy conversion process. However, the electron transfer from PSII to artificial components remains inefficient, which hinders the favorable conversion performance. Herein, a CdS-PSII hybrid photoelectrochemical (PEC) cell is proposed for overall water splitting, where PSII and the CdS-based PEC cell are connected by an ordered multi-step electron transfer pathway comprising two redox shuttles quinone/hydroquinone and ferricyanide/ferrocyanide coupled by a graphite-based galvanic cell. The hybrid system allows overall water splitting with 8.5 mu mol O2 h-1 and 17.7 mu mol H2 h-1 under simulated solar light, corresponding to a solar-to-hydrogen efficiency of 0.34%. Moreover, the tandem light absorption from CdS to PSII both improves the light utilization efficiency and prolongs the lifetime of PSII. This work may inspire new approaches to achieve Z-scheme water splitting in the field of artificial photosynthesis.