Decorating Cu2O with Ni-doped metal organic frameworks as efficient photocathodes for solar water splitting. (26th May 2023)

• Record Type: Journal Article
• Authors: Yu, Run; Chen, Qianqiao; Li, Wenhua; Yu, Xinyuan; Zhong, Qin
• Is Part Of: International journal of hydrogen energy. Volume 48:Number 45(2023)
• Page Start: 17065
• Page End: 17073
• Publication Date: 2023-05-26
• Subjects: Cu2O -- MOFs -- Ni-doped -- Photocathode -- PEC water Splitting; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2023.01.145
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Severe photocorrosion and fast photoexcited charges recombination hinder the application of Cu2 O in photoelectrochemical (PEC) water splitting. In this work, Ni-doped metal-organic frameworks is firstly applied to improve the performance of electrodeposited Cu2 O. A decorative layer of Ni-doped Cu3 (BTC)2 (Ni-CuBTC) was in-suit constructed on Cu2 O through solvothermal followed by ion-exchange. Cu2 O/Ni-CuBTC photocathodes increase absorption edge 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 Cu2 O photocathode. Here, the PEC water splitting performance of electrodeposited Cu2 O has been significantly improved with noble-metal-free decorations, which provides a new idea for solving the defects of Cu2 O based photocathode. Graphical abstract: Image 1 Highlights: Ni-CuBTC decorated Cu2 O as HER photocathode by solvothermal and ion-exchange. CuBTC can adjust the energy band structure and promote charges transfer. HER kinetics can be improved with Ni doping. Noble-metal-free Ni-CuBTC acts as co-catalyst, photosensitizer, and protector. It exhibits 3.4 times current density of bare Cu2 O with −1.51 mA/cm 2 at 0 VRHE .