Co_(3)S_(4)电极材料的制备及在碱性析氢反应中的重构行为研究

Preparation and Reconstruction Behavior in Alkaline Hydrogen Evolution Reaction of Co_(3)S_(4)Electrode Material

因为析氢反应(HER)电位远低于析氧反应(OER),催化剂的重构过程相对迟缓,所以其重构现象鲜有报道。为此,本工作通过水热和硫化两步法成功合成了自支撑碳布(CC)负载纯相Co_(3)S_(4)电极材料,其微观呈纳米颗粒组装的绿疣海葵状结构。该电极材料在1 mol/L KOH的HER电化学测试中就能发生快速、完全重构,催化活性显著提升,在100 mA·cm^(-2)时过电位降低约55 mV。诱发重构主要是硫组分浸出所致。重构后的电极材料物相为Co(OH)_(2),且形貌已完全转变为数层纳米片堆叠而成的大比表面花状结构,暴露出更多的活性位点,促进电解液与电极材料的接触,加速催化反应中的传质过程,进而提升催化活性。这一发现有助于科研工作者初步认识硫化物催化剂电极材料在HER催化过程中的重构行为。

The reconstruction phenomenon of catalyst in hydrogen evolution reaction(HER)is rarely reported due to its reaction potential being much lower than that of oxygen evolution reaction(OER).To this end,the self-supporting carbon cloth(CC)supported pure phase Co_(3)S_(4)electrode material was successfully synthesized by a hydrothermal combined sulfurized two-step approach,and the microstructure shows a green wart sea anemone-like structure assembled by nanoparticles.In the HER electrochemical test of 1 mol/L KOH,the electrode material can undergo rapid and complete reconstruction,and the catalytic activity is significantly improved.At 100 mA·cm-2,the overpotential decreases by about 55 mV.The reconstruction was mainly induced by sulfur leaching.The reconstructed electrode material phase is Co(OH)_(2),and its morphology has been completely transformed into a large specific surface flower structure formed by stacking several layers of nanosheets,exposing more active sites,promoting the electrolyte-electrode contact,accelerating the mass transfer process,thus improving catalytic activity.This discovery is helpful for researchers to preliminarily understand the reconstruction behavior of sulfide electrode materials in HER.