Severe photocorrosion and fast photoexcited charges recombination hinder the application of Cu2O in photoelectrochemical (PEC) water splitting. In this work, Ni-doped metal-organic frameworks is firstly applied to improve the performance of electrodeposited Cu2O. A decorative layer of Ni-doped Cu-3(BTC)(2) (Ni-CuBTC) was in-suit constructed on Cu2O through solvothermal followed by ion-exchange. Cu2O/Ni-CuBTC photocathodes increase absorption edge to similar to 800 nm, positive shift flat band position to 0.4 V, and decrease Tafel value to 74 mV/dec. These results confirm the decorative layer can extend light absorption, facilitate photoexcited charge separation and transfer, and enhance HER activity. A photocurrent density of-1.51 mA/cm(2) at 0 VRHE is obtained with the decoration of Ni-CuBTC, which is 3.4 times of pristine Cu2O photocathode. Here, the PEC water splitting performance of electrodeposited Cu2O has been significantly improved with noble-metal-free decorations, which provides a new idea for solving the defects of Cu2O based photocathode. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
展开▼
