Distinct Promotion of PEC Water Oxidation of Ta<sub>2</sub>O<sub>5</sub>/α-Fe<sub>2</sub>O<sub>3</sub>/Co–Ni PBA via Coupling Ni 3d with O 2p
Yuan Guan, Qiankun Deng, Dayu Wu, Shaomang Wang, Zhongyu Li, Shicheng Yan, Zhigang Zou
Abstract
The development of robust and effective photoanodes is crucial for photoelectrochemical hydrogen production via total water splitting. Herein, the Ta 2 O 5 /α-Fe 2 O 3 /Co–Ni PBA (TFPB-1) photoanode was constructed by the compositing n-type Ta 2 O 5 and n-type α-Fe 2 O 3 followed by the deposition of p-type Co–Ni PBA. The IPCE of TFPB-1 was increased to 35.4% compared to 13.9% for Ta 2 O 5 owing to the significantly improved light absorption efficiency, carrier separation efficiency and injection efficiency. The TFPB-1 achieved a current density of 2.78 mA cm –2 at 1.23 V (vs RHE), which was around 18.5 times that of Ta 2 O 5 . The OER overpotential over TFPB-1 was reduced to 0.59 V compared to 1.13 V for Ta 2 O 5, resulting in a substantial reduction in the free energy of PEC water oxidation over TFPB-1. As a result, TFPB-1 exhibited remarkably enhanced photoelectrocatalytic activity for oxygen evolution through water oxidation.