Efficient Visible-Light-Driven Hydrogen Production over Cu-Modified Polyoxotungstate Hybrids

Hydrogen energy is a renewable and clean source, which makes a great difference in future sustainable energy systems. Visible-light-driven photocatalysis reaction involves harnessing the abundance of sunlight for hydrogen production among many catalytic technologies. However, the fabrication of photocatalysts that have distinctive performance in visible light is still the primary challenge. Herein, two new Cu-modified polyoxotungstate hybrids, {[Cu₂(bim)₄(H₂O)₂](HBW₁₂O₄₀)₂·(H₂bim)₂·8H₂O} (1) (bim = [1,1'-methylenebis(1H-imidazole)]) and {[Cu₂(bim)₄(H₂O)₂](H₃PW₁₀Ti₂O₄₀)₂·(H₂bim)₂·8H₂O} (2), have been successfully isolated by bridging two saturated Keggin polyoxotungstates and copper-azole complexes. Not surprisingly, 2 holds higher reduction activity due to the more negative charge and stronger basicity on the terminal oxygen of Ti═O and bridge oxygen of Ti-O-W. The H₂ yield was 17075 μmol g^-1 h^-1 for 2 in the tunable light-driven H₂ production system, which is promising in the field of photocatalysis.