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

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.