Synergistic Pt/Cu Dual Cocatalysts on Monolithic TiO2–N Mesoporous Architectures for Efficient Solar-Driven Hydrogen Evolution

Monolithic photocatalysts present a transformative paradigm to reconcile the activity-stability-recovery trade-off inherent in conventional powder systems for photocatalytic hydrogen evolution. This study demonstrates a low-temperature synthesis of mesoporous Pt/Cu/TiO2–N catalysts in situ grown on frosted glass (Pt/Cu/TiO2–N/FP), where nitrogen doping amplifies Ti–O–Ti vibrational coupling and the hierarchical mesostructure creates sufficient active sites. The engineered Pt–Cu dual-cocatalyst system achieves exceptional synergy: Pt nanoparticles drive proton reduction while Cu2+ species prolong charge carrier lifetime through the Cu2+/Cu+ redox cycle, collectively enabling light absorption to the visible range. With optimized dual cocatalyst decoration (1.1 wt % Pt, 0.3 wt % Cu2+), the monolithic mesoporous architecture delivers a stable hydrogen evolution rate of 187.1 μmol h–1. Importantly, our mild fabrication strategy (NH3 treatment at 100 °C, Cu2+ grafting at 60 °C) establishes a generalizable protocol for temperature-sensitive substrate functionalization. This work pioneers a dual-engineering approach combining substrate-compatible synthesis with electronic structure modulation, offering a pathway toward industrially viable solar hydrogen reactors.