Crystalline/amorphous CoP/MnOx heterostructure derived from phase separation for electrochemical catalysis of alkaline hydrogen evolution reaction. (22nd January 2023)

• Record Type: Journal Article
• Authors: Yu, Rui; Du, Ying-Xia; Zhao, Heng-Fan; Cao, Fei-Fei; Lu, Wang-Ting; Zhang, Geng
• Is Part Of: International journal of hydrogen energy. Volume 48:Number 7(2023)
• Page Start: 2593
• Page End: 2604
• Publication Date: 2023-01-22
• Subjects: Water splitting -- Alkaline HER -- Phase separation -- Interface effect -- Crystal refinement; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2022.10.049
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The electrochemical water splitting in alkaline media is troubled by the lack of efficient electrocatalysts for hydrogen evolution reaction (HER). Herein, a crystalline/amorphous CoP/MnOx heterostructure is converted from a single-phase bimetallic Co–Mn oxide by phase separation strategy. The CoP/MnOx heterostructure only requires an overpotential of 135 mV to reach 10 mA cm −2 in 1 M KOH, which is lower than that of CoP (184 mV). The interface effect between CoP and MnOx is beneficial to the improvement of HER activity, which is confirmed by means of selective etching of MnOx and infrared spectroscopy. Moreover, the crystal size of CoP phase in the heterostructure is lower than that of the mono-component CoP. Furthermore, the decrease of precursor crystal size will give rise to a decrease in the CoP crystal size of heterostructure. The decline of crystal size results in higher active surface area and greater number of interfaces. Graphical abstract: Image 1 Highlights: CoP/MnOx heterostructure is built by phase separation from a single-phase precursor. The interface effect between CoP and MnOx on HER activity is verified. The crystal refinement effect is observed in phase separation strategy. The smaller precursor crystal results in smaller CoP in the heterostructure.