Interface Engineering of MoS2 for Electrocatalytic Performance Optimization for Hydrogen Generation via Urea Electrolysis

Developing highly efficient and low-cost nonprecious electrocatalysts for hydrogen evolution reaction (HER) has a pivotal impact on the emergence of hydrogen energy. Herein, quaternary electrocatalyst characterized by abundant interfaces supported on carbon cloth (denoted as Mo–Co–S–Se/CC) is designed through a facile solvothermal and post-low-temperature selenylation process, which delivers excellent catalytic performances in HER, oxygen evolution reaction (OER), and urea oxidation reaction (UOR) in alkaline electrolyte. Benefiting from the rich interfaces, the designed catalyst delivers current densities of 10 and 100 mA cm–2 with low overpotentials of 58 and 167 mV, respectively, and small Tafel slope of 84 mV dec–1 for HER. For the anodic OER, only 350 mV overpotential is needed to drive 100 mA cm–2 in 1 M KOH solution. Moreover, Mo–Co–S–Se/CC also presents remarkable catalytic activity for UOR in 1 M KOH solution, which provides another way to substitute the sluggish OER to reduce the cost of hydrogen production. As a proof of concept, overall water-splitting tests are measured with Mo–Co–S–Se/CC as both anode and cathode, respectively, in 1 M KOH solution with 0.5 M urea; only 1.4 V is required to drive 10 mA cm–2, much lower than that for urea-free electrolyte with 1.62 V.