Bridging Copper-Oxygen-Titanium Bonds for Methanol Photoreforming to Hydrogen on Zero-Dimensional/Two-Dimensional...

Solar-driven hydrogen (H₂) evolution from liquid organic hydrogen carriers (LOHCs) by using rationally designed heterojunctions represents a transformative approach toward carbon neutrality. However, practical implementation is hindered by inefficient charge separation and transport, predominantly due to suboptimal interfacial engineering in conventional heterostructures. Here, dense Cu-O-Ti bonds are created between zero-dimensional (0D) Cu_xO nanocrystals (2-3 nm) and two-dimensional (2D) TiO₂ architectures via a mechanism mediated by unsaturated oxygen atoms, which serve as electron mobility highways to ease excited-state relaxation and recombination. The optimized heterostructure achieves a record-high H₂ evolution activity (64 mmol·g^-1·h^-1) from methanol photoreforming, outperforming pristine TiO₂ and commercial TiO₂ by 9-fold and 428-fold, respectively. Dynamic Cu²⁺/Cu⁺ redox cycling not only contributes to durability in extracting protons from methanol to H₂ but also activates water molecules, promoting methanol oxidation into formic acid. This work points to a feasible path to overcome the quantum mechanical barriers for methanol photoreforming, powering an efficiency leap for solar-to-H₂ conversion.