Bimetallic sulfide interfaces: Promoting destabilization of water molecules for overall water splitting

Electrochemical water splitting has drawn tremendous research interest for scalable generation of clean hydrogen fuel from water. However, it is difficult to develop a catalyst possessing efficient activity of both oxygen and hydrogen evolution in the same reaction media. Herein, we developed an interfacial bimetallic sulfide (Ni3S2/FeS) to operate efficiently in alkaline media for both oxygen evolution reaction and hydrogen evolution reaction. Calculation and experiment results revealed a strong electron interaction on the Ni3S2/FeS nanointerfaces, optimizing the adsorption energies for H and OH groups and thus improving the water electrolysis performance. The obtained Ni3S2/FeS exhibited superior electrocatalytic performances with overpotentials of 295 and 190 mV at 30 mA cm−2 toward OER and HER, respectively. An alkaline electrolyzer based on Ni3S2/FeS electrodes only 1.61 V to reach the current density of 10 mA cm−2.