Single-Atom Co-Ultrafine RuOx Clusters Codecorated TiO2 Nanosheets Promote Photocatalytic Hydrogen Evolution: Modulating Charge Migration, H+ Adsorption, and H2 Desorption of Active Sites

Abstract

Ru as a cocatalyst has attracted wide attention as a substitute for Pt precious metal. However, the strong interaction between Ru and H atoms reduces the efficiency of hydrogen (H2) desorption and slows the overall hydrogen evolution reaction (HER) efficiency. How to further improve the efficiency of Ru-based cocatalyst is challenging. Herein, single-atom Co-ultrafine RuOx clusters codecorated TiO2 nanosheets for photocatalytic HER are synthesized using a simple hydrothermal–calcination method. Experiments and theoretical calculations demonstrate that Co atoms can serve as a specific electronic medium, promoting electron enrichment at RuOx, thereby enhancing the adsorption of H+. Moreover, the electronic state of the interaction between adjacent Co atoms and RuOx is conducive to the desorption of H2. As a result, the proposed photocatalyst system gives a classy photocatalytic HER performance. The hydrogen production rate at stationary point reaches up to 20.20 mmol g−1 h−1, and the apparent quantum yield at 365 nm is 86.5%. It is worth noting that the hydrogen production rate in seawater is as high as 9.83 mmol g−1 h−1. This work offers precise guidance to design catalysts for efficient photocatalytic H2 production from the in-depth understanding of the electronic coupling effect of coupling active sites.