Construction of nickel stannum based sulfide as efficient electrocatalysts for freshwater, seawater and urea oxidation

Electrocatalytic water splitting is considered as a green and efficient way of hydrogen production . How to promote the performance of electrode and develop stable non-precious metal catalysts has caused extensive research. One of the effective strategies is combining two or more catalytic materials to build heterogeneous structures. In this paper, a series of Co 0.3 -Ni 3 S 2 /Ni 3 Sn 2 S 2 heterostructured materials were synthesized to in-situ grow Ni 3 S 2 /Ni 3 Sn 2 S 2 on Ni foam with a 3D porous structure by modulating the substance ratio of elemental cobalt and elemental sulfur through a one-step hydrothermal process. The materials have superior oxygen evolution reaction (OER) properties and urea oxidation reaction (UOR) performance. Under an alkaline electrolyte of 1 M KOH, for OER, Co 0.3 -Ni 3 S 2 /Ni 3 Sn 2 S 2 only requires overpotential of 251 mV to obtain a current density of 10 mA cm −2 . In an alkaline solution of 1 M KOH +0.5 M urea, for UOR, only the potential of 1.326 V was demanded for the catalyst to reach a current density of 50 mA cm −2 , but its stability over 15 h was average. Density Functional Theory (DFT) analyses suggest that Co–Ni 3 S 2 has better metallic properties and promote the dynamics in catalysis. This study put forward a new thought for future research on nickel-tin binary metal sulfide hybrid electrocatalysts with excellent freshwater, seawater and urea oxidation properties.