Engineering a Self‐Grown TiO₂/Ti‐MOF Heterojunction with Selectively Anchored High‐Density Pt Single‐Atomic Cocatalysts for Efficient Visible‐Light‐Driven Hydrogen Evolution

Abstract A photocatalyst TiO 2 /Ti‐BPDC‐Pt is developed with a self‐grown TiO 2 /Ti‐metal–organic framework (MOF) heterojunction, i.e., TiO 2 /Ti‐BPDC, and selectively anchored high‐density Pt single‐atomic cocatalysts on Ti‐BPDC for photocatalytic hydrogen evolution. This intimate heterojunction, growing from the surface pyrolytic reconstruction of Ti‐BPDC, works in a direct Z‐scheme, efficiently separating electrons and holes. Pt is selectively anchored on Ti‐BPDC by ligands and is found in the form of single atoms with loading up to 1.8 wt %. The selective location of Pt is the electron‐enriched domain of the heterojunction, which further enhances the utilization of the separated electrons. This tailored TiO 2 /Ti‐BPDC‐Pt shows a significantly enhanced activity of 12.4 mmol g −1 h −1 compared to other TiO 2 ‐ or MOF‐based catalysts. The structure‐activity relationship further proves the balance of two simultaneously exposed domains of heterojunctions is critical to fulfilling this kind of catalyst.