Synergistic ZnS@Co₃O₄/MXene hybrid derived from ZIF-67 for high-performance supercapacitors

Supercapacitors have garnered significant interest from researchers owing to their high-power density, rapid charge/discharge capabilities, and extended cycle life. In this context, the design and development of electrode materials that offer both high performance and enhanced stability remain key areas of investigation in supercapacitor research. In this work, a novel ZnS@Co₃O₄/MXene composite was successfully synthesized via a co-assembly strategy using (Zeolitic imidazolate framework) ZIF-67 and ZIF-8 as a precursor for Co₃O₄ and ZnS. The structural, morphological, and surface characteristics of the composite were systematically investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). XRD confirmed the successful formation of crystalline Co₃O₄ and ZnS phases anchored on the Ti₃C₂Tₓ MXene layers, while SEM images revealed a uniformly distributed network of ZnS and Co₃O₄ nanoparticles anchored on the MXene sheets. XPS analysis further verified the coexistence of Zn²⁺, Co²⁺/Co³⁺, and Ti-C surface bonds. Electrochemical investigations demonstrated outstanding pseudocapacitive performance, with a high specific capacitance of 306 F/g at 1 A/g and a low charge-transfer resistance (Rct = 3.2 Ω). Moreover, the electrode retained 88 % of its initial capacitance after 5000 cycles, reflecting excellent structural stability and durability. These results establish ZnS@Co₃O₄/MXene as a highly promising and efficient electrode material for next-generation high-performance supercapacitors.