Regulating the Electronic Structure and Water Adsorption Capability by Constructing Carbon-Doped CuO Hollow Spheres for Efficient Photocatalytic Hydrogen Evolution

Graphical Self-templated strategy : This work reports a self-templated strategy for the preparation of carbon-doped CuO hollow spheres (C−CuO HSs) featuring both modulated electronic structure and high water-adsorption capability through thermal transformation of a hierarchical MOF. The as-synthesized C−CuO HSs exhibits remarkable photocatalytic performance with a H 2 evolution rate of 67.3 mmol/g/h and an apparent quantum efficiency of 25.3 %. Copper(II) oxide featuring a narrow bandgap and low toxicity has been frequently applied in the visible-light-driven photocatalytic hydrogen evolution, but it suffers from large intrinsic overpotential and low water adsorption capacity. Herein, we report a self-templated strategy for the preparation of carbon-doped CuO hollow spheres (C−CuO HSs) through thermal transformation of a hierarchical MOF. The hierarchical Cu−MOFs not only act as a template to form interior voids during the thermal transformation, but also serve as precursors to dope C atoms into the CuO lattice. The as-synthesized C−CuO HSs exhibits remarkable photocatalytic performance with a H 2 evolution rate of 67.3 mmol/g/h and the apparent quantum efficiency of 25.3 % at 520 nm in the present of eosin-Y photosensitizer. The high performance of C−CuO HSs is attributed to the hierarchical porous structure and modulated electronic structure of CuO by C-doping with well exposed reactive sites, high water adsorption capability, and low water reduction reaction barrier. The results presented in this work might shed light on the design of high-performance photocatalysts for various energy-related applications.