High-Entropy Sulfide (FeCoNiCrMn)S₂ for Room Temperature NO₂ Sensors

Metal sulfides have been extensively studied in the field of chemical sensors working at room temperature (RT). However, compared to metal oxides, metal sulfides often suffer from incomplete recovery and unsatisfactory selectivity. In this work, we for the first time report the high-entropy sulfide (HES) (FeCoNiCrMn)S₂, prepared by the solvothermal method, is a promising candidate for utilization as the sensitive layer in gas sensors. Unlike traditional single-metal sulfides, this HES (FeCoNiCrMn)S₂ exhibits reversible recovery for NO₂ at RT as well as excellent selectivity. To unveil the sensing mechanism, we simulated the adsorption and charge transfer between (FeCoNiCrMn)S₂ and gas molecules by the density functional theory (DFT) calculation, revealing the reason (FeCoNiCrMn)S₂ is uniquely selective to NO₂. This work explores the application potential of HES (FeCoNiCrMn)S₂ as an RT sensor and enriches the material selection for NO₂ sensors.