Boosting Photocatalytic Activity Through Dual Functionalization: Oxygen Vacancy‐Rich 2D Mesoporous TiO ₂ Nanosheets Integrated with Bimetallic Nanoclusters

Abstract Photocatalytic hydrogen production has emerged as a promising strategy for sustainable energy generation. However, the overall efficiency remains hindered by the challenges of charge recombination and low carrier utilization efficiency. In this study, 2D mesoporous TiO ₂ nanosheets (mTSs) with precisely modulated structural parameters are successfully engineered through a monomicelle‐directed interfacial assembly approach to address the challenges. By implementing a sequential reduction protocol, ultrasmall PdPt bimetallic nanoclusters (≈3 nm) with exceptional dispersion uniformity are further integrated onto the mTSs matrix. The resultant mTSs‐Pd _0.5 Pt ₁ photocatalyst demonstrates an ordered 2D hexagonal mesostructure (p6mm) featuring 3D interconnectivity, with optimized architectural parameters including a mesopore diameter of 23 nm, enhanced specific surface area (157 m ² g ⁻¹ ), and substantial pore volume (0.27 cm ³ g ⁻¹ ). Systematic characterization reveals that the synergistic combination of 2D mesoporous structural advantages with surface modifications (oxygen vacancy engineering and bimetallic cocatalyst) significantly promotes charge separation while suppressing carrier recombination. These coordinated enhancements translate to a record hydrogen evolution rate of 17.4 mmol h ⁻¹ g ⁻¹ under visible light irradiation, outperforming most reported TiO ₂ ‐based systems. The findings establish a dual engineering paradigm through structural topology control and interfacial electronic modulation for developing high‐performance photocatalytic systems.