Sulfophobic and Vacancy Design Enables Self‐Cleaning Electrodes for Efficient Desulfurization and Concurrent Hydrogen Evolution with Low Energy Consumption

Abstract

AbstractSulfide oxidation reaction (SOR) is one central step of electrochemical desulfurization and sulfur‐based batteries. However, the electrochemical performance of desulfurization and sulfur batteries has been severely hindered by sulfur passivation. Here, a discovery of sulfophobic phenomenon of electrocatalysts having weak interaction to sulfur species is reported. A self‐cleaning NiS2 electrode is developed to avoid the long‐perplexing passivation issue of solid sulfur during the SOR. Furthermore, sulfur‐vacancies are engineered into NiS2 lattice to synthesize v‐NiS2 for the hydrogen evolution reaction (HER). The resultant lattice expansion and electron redistribution can adjust the adsorbed hydrogen to reach a nearly thermos‐neutral state, enabling high catalytic activity for the HER. By coupling the HER and SOR, efficient desulfurization and simultaneous hydrogen production is demonstrated. Bifunctional NiS2 enables such a one‐stone‐kills‐two‐birds strategy to realize continuous electrochemical desulfurization with superior energy efficiency (1.05 gsulfur Wh−1). As a general design principle, sulfophobic electrocatalysts can improve the properties of lithium–sulfur batteries by minimizing the passivation of S8 during charge. In brief, interfacial interaction between electrocatalysts and sulfur species are systematically investigated and a sulfophobic strategy to significantly enhance the electrochemical performance of the SOR is offered.