Temperature Directed Solid‐State Sulfidation of MOF‐Derived Bi 2 S 3 /N‐Doped Carbon Composites for Enhanced Supercapacitor Performance

ABSTRACT Rationally designing nanostructured surface architectures is key to enhancing the energy storage performance of electrode materials. The synthesis of composite bismuth sulfide nitrogen doped carbon as an active electrode material for supercapacitor applications via a simple, scalable, and MOF‐derived solid‐state pyrolysis route is presented herein. A Bi‐MOF precursor synthesized through a solvothermal method is subsequently converted into Bi 2 S 3 via a solid‐state reaction involving grinding Bi‐MOF and thiourea and thermally treating the mixture under an inert atmosphere. Physicochemical characterization of crystalline phase formation and morphological evolution revealed a unique 3D sea coral‐like nanostructures architecture. An optimized sample (BSNC‐700) exhibits a remarkable specific capacity of 2154.8 C g −1 at 1 mA cm −2 in 1 m KOH. ASSC and SSSC devices of BSNC‐700 achieves a specific capacitance of 146.4 and 136.8 F g −1 at 1 mA cm −2 . The corresponding specific energy and power levels of ASSC and SSSC devices are 46.65 and 39.85 Wh kg −1 at 980 and 782 W kg −1 respectively with excellent cyclic stability, and can power a mini‐fan. This study highlights MOF‐derived solid‐state synthesis as a promising strategy for improving the charge storage capability, stability, and scalability of supercapacitors for commercial energy storage applications.