One stone three birds: 2-thiobarbituric acid as etching agent, sulfur source and ligand for one-step synthesis of Ni3S2/FeOOH@iron thiobarbituric acid-based framework composites toward efficient water oxidation

Metal-organic frameworks (MOFs) have garnered extensive attention in the area of oxygen evolution reaction (OER) electrocatalysis because of their remarkable specific surface area and tunable morphologies and composition. However, the low electrical conductivity and poor stability severely hinder their potential as high-performance OER catalysts. Herein, we employed 2-thiobarbituric acid as etching agent, sulfur source and ligand, and nickel-iron foam as the metal source and substrate, to synthesize Ni 3 S 2 /FeOOH@iron thiobarbituric acid-based framework (Fe-TBA) composite on the nickel-iron foam via a one-step hydrothermal method. Experimental findings reveal that Ni 3 S 2 can modulate the morphological structure of FeOOH@Fe-TBA as well as boost its stability, consequently delivering exceptional OER activity. It requires merely an overpotential of 232 mV to reach a current density of 10 mA cm −2 , and the Tafel slope is 43.1 mV dec −1 . Furthermore, when an overall water-splitting system is constructed where Ni 3 S 2 /FeOOH@Fe-TBA and Pt/C act as the anode and cathode, respectively, it operates at a mere 1.52 V under a current density of 10 mA cm −2 and maintains the stable performance for more than 100 h. This study offers a new strategy for fabricating sulfides/MOFs composites to realize highly efficient water oxidation.