Electron beam assistant controllable synthesis of 2D, 3D and 0D CuxO loaded on graphene for high-performance bifunctional photocatalytic and Fenton-like catalysts

Abstract

Narrow wavelength response range and low utilization of light greatly limit the practical application of photocatalysts. Aiming at the insufficiency, a visible light photocatalytic and Fenton-like bifunctional catalyst based on CuxO loaded on graphene nanosheets (CuxO/GNSs) has been designed and prepared. In the synthesis process, the hydration electrons (eaq−, −2.8 V) generated by the radiolysis of water by high-energy electron beam (EB), are used as the reducing agent to reduce CuO/GNSs to CuxO/GNSs. Through adjusting the irradiation dose of EB, the concentration of eaq− in the reaction system can be easily controlled, and a series of CuxO/GNSs with different reduction degrees and morphology are prepared. When the EB irradiation dose increases from 70 to 350 kGy, the morphology of CuxO loaded on GNSs change from 2D nanosheets to 3D nanocubes, then to 0D nanodots. Through the water treatment experiments, the CuxO/GNSs prepared at 350 kGy irradiation dose (CuxO/GNS350) exhibits the best photocatalytic and Fenton-like catalytic performance among all the samples. It can be attributed to the ultrafine nanodots structure (10–15 nm) of Cu2O in CuxO/GNS350, which can shorten the distance of photogenerated charges migration to the material surface, as well as provide a wealth of active reaction sites for reactants. This work provides an efficient and eco-friendly EB assistant method to prepare CuxO/GNS with controllable size and dimensions for high performance bifunctional photocatalytic and Fenton-like catalysts.