Heterostructuring Uniform 2D CdS on Ru/Ti₃C₂‐TiO₂ via In situ Oxidized Ru‐Loaded MXene for Boosting Photocatalytic H₂ Production

Abstract Building heterojunctions and exposing more catalytic active sites are effective strategies to enhance the photocatalytic hydrogen evolution activity. Herein, TiO₂ nanosheets are oxidized in situ on Ru‐loaded MXene as carriers and subsequently loaded with uniform 2D CdS via hydrothermal method to obtain 2D Ru/Ti₃C₂‐TiO₂/CdS composite photocatalysts that integrate heterojunctions and cocatalysts. The formation of heterojunction between CdS and TiO₂ is conducive to promoting the separation and transfer of photogenerated charges, simultaneously, Ru/Ti₃C₂ with the fully exposed Ru and Ti₃C₂ can act as effective active sites of photocatalytic hydrogen production reaction. The composite photocatalyst exhibits an improved hydrogen production rate with 5479 µmol g⁻¹ h⁻¹, which is 5, 3, and four times more than that of pristine CdS, CdS loaded Ti₃C₂‐TiO₂ and CdS loaded Ru‐TiO₂ respectively. The results reveal that the notable enhancement in performance can primarily be ascribed to the introduction of the TiO₂/CdS heterojunction and the efficient cocatalysts of Ru/Ti₃C₂. Moreover, the 2D Ti₃C₂ with high conductivity as carriers can increase charge transfer, and its 2D structure can serve as a template for growing 2D photocatalysts with higher activity. The interface engineering with multiple interfaces can offer novel insights for the advancement of efficient hydrogen evolution reaction catalysts.