Ultrafast Synthesis of NiCo Alloy Catalyst by Joule Heating for Electrocatalytic Hydrogen Evolution Reaction

Abstract

Identifying effective synthesis strategies that can obtain high-performance electrocatalysts is pivotal for realizing a hydrogen economy. Nickel-cobalt (NiCo) alloy electrocatalyst is a promising candidate for hydrogen evolution reaction (HER), while the traditional approach of synthesizing NiCo alloy electrocatalyst is generally time-consuming, and the physiochemical feature of the NiCo is unsatisfactory. Herein, we report the ultrafast synthesis of NiCo alloy nanocatalysts with a Joule heating (JH) approach. We show that ultrasmall NiCo alloy nanoparticles that are uniformly and intimately distributed on carbon cloth can be obtained in just 0.6 seconds using the JH approach, while the NiCo catalysts prepared with traditional thermal treatment exhibit agglomerated and large particles. The as-prepared NiCo alloy electrocatalyst with JH shows a favorable activity for HER with low overpotentials of 83 and 220 mV to achieve current intensities of 10 and 100 mA cm ^-2 , respectively, outperforming the NiCo alloy electrocatalysts prepared with traditional approaches. Moreover, the NiCo alloy electrocatalyst maintains excellent stability during the long-term reaction for 200 h, demonstrating its potential for large-scale deployment.