Boosting Photocatalytic Water Oxidation Over Bifunctional Rh<sup>0</sup>‐Rh<sup>3+</sup> Sites
Yuanwei Liu, Li Jie Wang, Hao Zhang, Hai Yang Yuan, Qinghua Zhang, Lin Gu, Hai Feng Wang, P. Hu, Peng Fei Liu, Zheng Jiang, Hua Gui Yang
Abstract
Abstract Photocatalytic water splitting provides an economically feasible way for converting solar energy into hydrogen. Great efforts have been devoted to developing efficient photocatalysts; however, the surface catalytic reactions, especially for the sluggish oxygen evolution reaction (OER), still remain a challenge, which limits the overall photocatalytic energy efficiency. Herein, we design a Rh n cluster cocatalyst, with Rh 0 ‐Rh 3+ sites anchoring the Mo‐doped BiVO 4 model photocatalytic system. The resultant photocatalyst enables a high visible‐light photocatalytic oxygen production activity of 7.11 mmol g −1 h −1 and an apparent quantum efficiency of 29.37 % at 420 nm. The turnover frequency (TOF) achieves 416.73 h −1 , which is 378 times higher than that of the photocatalyst only with Rh 3+ species. Operando X‐ray absorption characterization shows the OER process on the Rh 0 ‐Rh 3+ sites. The DFT calculations further illustrate a bifunctional OER mechanism over the Rh 0 ‐Rh 3+ sites, in which the oxygen intermediate attacks the Rh 3+ sites with assistance of a hydrogen atom transfer to the Rh 0 sites, thus breaking the scaling relationship of various oxygen intermediates.