Boosting Photocatalytic Hydrogen Evolution Activity by Accelerating Water Dissociation over Rh/Zn(OH)₂ Catalyst in Alkaline Solution

Abstract

In the present work, we report that a Rh/Zn(OH) 2 catalyst, prepared by an in situ photodeposition strategy, can enhance water dissociation kinetics to boost the photocatalytic hydrogen evolution reaction (HER) in the mild alkaline environment. In comparison to a Rh NP catalyst, the Rh/Zn(OH) 2 catalyst exhibited a 3-fold increase in the rate of H 2 evolution. In-depth characterization manifests that the impressive photocatalytic performance was ascribed to multiple factors. First, the strong interaction between Rh nanoparticles (NPs) and Zn(OH) 2 , coupled with the 3D network structure of amorphous Zn(OH) 2 for Eosin Y (EY) molecule adsorption, ensured the rapid transfer of photogenerated carrier pairs. Second, the kinetics of water dissociation over the Rh/Zn(OH) 2 catalyst was accelerated in the mild alkaline solution. As a result, the Rh/Zn(OH) 2 catalyst achieved a high HER rate of 60.9 mmol•g −1 •h −1 , and the apparent quantum efficiency (AQE) reached 79.5% at 430 nm. Overall, our work will expand the candidate materials to design high-performance catalysts for photocatalytic H 2 evolution in alkaline solutions.