Amorphous NixCoyP-supported TiO2 nanotube arrays as an efficient hydrogen evolution reaction electrocatalyst in acidic solution

摘要

Bimetallic phosphides have been attracting increasing attention due to their synergistic effect for improving the hydrogen evolution reaction as compared to monometallic phosphides. In this work, NiCoP modified hybrid electrodes were fabricated by a one-step electrodeposition process with TiOsub2/sub nanotube arrays (TNAs) as a carrier. X-ray diffraction, transmission electron microscopy, UV–vis diffuse reflection spectroscopy, X-ray photoelectron spectroscopy and scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy were used to characterize the physiochemical properties of the samples. The electrochemical performance was investigated by cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy. We show that after incorporating Co into Ni–P, the resulting Nisubx/subCosuby/subP/TNAs present enhanced electrocatalytic activity due to the improved electron transfer and increased electrochemically active surface area (ECSA). In 0.5 mol Lsup?1/sup Hsub2/subSOsub4/sub electrolyte, the Nisubx/subCosuby/subP/TNAs (x = 3.84, y = 0.78) demonstrated an ECSA value of 52.1 mF cmsup?2/sup, which is 3.8 times that of Ni–P/TNAs (13.7 mF cmsup?2/sup). In a two-electrode system with a Pt sheet as the anode, the Nisubx/subCosuby/subP/TNAs presented a bath voltage of 1.92 V at 100 mA cmsup?2/sup, which is an improvment of 79% over that of 1.07 V at 10 mA cmsup?2/sup.