Abstract
Solar-driven photoelectrochemical CO(2) reduction represents a promising approach for the production of renewable liquid fuel but is limited by low photocurrent, the need for an external bias, and low carbon efficiency. This work employs a TiO(2)-CdS/Se-ZnSe/S photoanode to drive the sulfur oxidation reaction, achieving a photocurrent density of 12.7 mAcm(-2) under AM 1.5G illumination and with an 87% retention after 100 h of continuous operation. Furthermore, through tailoring the adsorption capability for the (*)OCHO intermediate, the Cu(6)Sn(5) catalyst exhibits a Faradaic efficiency of 92.8% for formic acid at -1.15 V in acidic media and maintains stability above 90% during a 120-h test. Finally, the constructed system achieves bias-free photoelectrochemical CO(2) reduction to HCOOH and delivers a yield of up to 172.9 µmolh(-1)cm(-2) over an 85-h long-term test, outperforming conventional solar-driven systems. These findings highlight a cost-effective strategy for solar-driven liquid fuel production and provide valuable design concepts and insights into the development of photoelectrochemical systems.