A Cu+1/Cu0-TiO2 mesoporous nanocomposite exhibits improved H2 production from H2O under direct solar irradiation

•Mesoporous TiO2 exhibiting better surface area 188 m2 g−1 and structural properties.•Formation of photostable Cu+/Cu-TiO2 ternary hybrid nanocomposite catalyst.•Water decomposition under direct sunlight irradiation using methanol as h+ scavenger.•Improved apparent quantum yield (AQE = 11.39%) of Cu-mpTiO2 for H2 evolution.•Efficient photostability and recyclability of Cu-mpTiO2 for several cycles.

A photostable sunlight-responsive mesoporous Cu+1/Cu0-TiO2 (Cu-mpTiO2) photocatalyst has been fabricated for the H2 production from water. Structural analysis revealed the anatase polymorph of TiO2 with mesoporous characteristics and an average particle size of ∼32 nm. Mesoporous TiO2 was observed to possess high surface area (188 m2 g−1) and pore size (0.32 nm). HRTEM studies suggested the deposition of Cu in Cu0 and Cu+1 oxidation states with three distinct lattice fringes of 0.21, 0.25, and 0.35 nm for Cu, Cu2O, and TiO2 respectively. Cu-mpTiO2 produced 1000 μmol of H2 (AQE = 11.39%) under sunlight irradiation, which is severalfold more than obtained with Cu impregnated on commercial Cu-TiO2 (P25). The photostability of the Cu-mpTiO2 increased after recycling because the excess Cu+1 (binding energy = 533.5 eV) is reduced to Cu0 (533.3 eV) and the excess holes in the valance band of Cu2O oxidize Cu0 to Cu+1.

Graphical abstractDownload high-res image (114KB)Download full-size image