High-Entropy\nSulfide (FeCoNiCrMn)S<sub>2</sub> for\nRoom Temperature NO<sub>2</sub> Sensors

Metal sulfides have been extensively studied in the field\nof chemical\nsensors working at room temperature (RT). However, compared to metal\noxides, metal sulfides often suffer from incomplete recovery and unsatisfactory\nselectivity. In this work, we for the first time report the high-entropy\nsulfide (HES) (FeCoNiCrMn)S<sub>2</sub>, prepared by the solvothermal\nmethod, is a promising candidate for utilization as the sensitive\nlayer in gas sensors. Unlike traditional single-metal sulfides, this\nHES (FeCoNiCrMn)S<sub>2</sub> exhibits reversible recovery for NO<sub>2</sub> at RT as well as excellent selectivity. To unveil the sensing\nmechanism, we simulated the adsorption and charge transfer between\n(FeCoNiCrMn)S<sub>2</sub> and gas molecules by the density functional\ntheory (DFT) calculation, revealing the reason (FeCoNiCrMn)S<sub>2</sub> is uniquely selective to NO<sub>2</sub>. This work explores the\napplication potential of HES (FeCoNiCrMn)S<sub>2</sub> as an RT sensor\nand enriches the material selection for NO<sub>2</sub> sensors.