A 20-core copper(i) nanocluster as electron–hole recombination inhibitor on TiO2 nanosheets for enhancing photocatalytic H2 evolution

Abstract

For the design of atom-precise copper nanoclusters, besides the exploration of their aesthetic cage-like architectures, their structural modulation and potential applications are being extensively explored. Herein, an atom-precise 20-core copper(I)-alkynyl nanocluster (UJN-Cu₂₀) protected by ethinyloestradiol ligands issynthesized. By virtue of outer-shell hydroxyl groups, UJN-Cu₂₀ could be uniformly modified on the surface of TiO₂ nanosheets via hydrogen bonding interactions, thus forming an efficient nanocomposite photocatalyst for hydrogen evolution. By constructing a Z-scheme heterojunction, the photocatalytic hydrogen evolution activity of the nanocomposite (13 mmol g⁻¹ h⁻¹) significantly improved as compared to that of TiO₂ nanosheets (0.4 mmol g⁻¹ h⁻¹). As a narrow bandgap cocatalyst, UJN-Cu₂₀ is confirmed to effectively inhibit the electron–hole recombination on the surface of the TiO₂ nanosheet, which provides a new concept for the design of copper cluster-assisted effective photocatalysts.