Highly active electrocatalysis of hydrogen evolution reaction in alkaline medium by Ni–P alloy: A capacitance-activity relationship

Abstract

Different weights of amorphous Ni–P alloy with same P contents were electrodeposited on nickel plate with same area used as cathode for hydrogen evolution reaction (HER). The amorphous Ni–P alloy coatings were characterized for their surface morphology and composition through Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDS) techniques, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis. The electrocatalytic activity for HER in alkaline medium is determined by linear scan voltammetry (LSV) and a relationship between HER activity and capacitance is established. The capacitance varies with the loading of the Ni–P on Ni plate but the activity for HER is directly proportional to the capacitance in alkaline and vice versa. 3#Ni–P/Ni containing 3.85 mg Ni–P alloy with highest capacitance performs the best catalytic activity. This work provides direct evidence to explore the capacitance influence on the electrocatalystic activity for the HER.