Multifunctional MoS2/Ni9S8/NF catalyst for synchronous desulfurization and hydrogen evolution by self-driven system

Abstract

Here, we introduce a self-driven system powered by a Zn-air battery to facilitate an electrocatalytic sulfide oxidation reaction coupled with a hydrogen evolution reaction (SOR||HER), thereby achieving the simultaneous production of sulfur and hydrogen. A heterostructured MoS2/Ni9S8/NF rod-like nanoarray was synthesized via a simple hydrothermal method for use in this system. Experimental results reveal that the unique rod-like array structure and robust interface coupling effect not only improve catalyst conductivity and mass transfer but also facilitate electron redistribution to form high-valence nickel (Ni3+) and electron-rich metal-sulfur active centers. Consequently, the MoS2/Ni9S8/NF catalyst exhibits excellent activity (SOR: η100 = 0.311 V; HER: η100 = 0.134 V), and long stability (480 h) in both SOR and HER processes. A current density of 100 mA cm-2 can be achieved by applying only 0.674 V in SOR||HER system. Moreover, by integrating the Zn-air battery and SOR||HER system, the self-driven system achieved an impressive hydrogen production rate of 5.50 mmol min-1 gcatalyst-1 and stable and efficient hydrogen production for up to ~5000 min. In conclusion, this work establishes a self-driven system utilizing trifunctional catalysts for simultaneous hydrogen production and desulfurization, which is expected to achieve high economic efficiency, sustainable development, and environmental remediation.