TiO2 nanowire-composited nickel-based electrocatalyst towards enhanced hydrogen evolution reaction in alkaline solution

Abstract

The highly efficient Ni-TiO₂ nanowire (NTw) composite electrode was synthesized by a simple, fast and low cost composite electrodeposition technique for hydrogen evolution reaction (HER). The unique flocculent structure of Tw increased the specific surface area of the composite electrode and accelerated the rate of material exchange and charge transfer during the HER. When Tw concentration was 7 g L⁻¹, the minimum hydrogen evolution overpotential of the NTw-7 composite electrode was only 167 mV at the current density of 10 mA cm⁻¹, demonstrating the best hydrogen evolution performance. Apart from its good catalytic activity, NTw-7 also exhibited better hydrogen evolution stability. HER durability tests carried out for 50 h did not change significantly (only 4 mV). Furthermore, the OH_ads species on the surface of TiO₂ were helpful for the formation of absorbed H_ads species, which is the rate-determining step for HER. This study presents a new strategy for modified Ni-based metallic oxide composite material.