Solvothermal synthesis of ZnV2O6/g-C3N4 composites for high-performance supercapacitors

Composite materials formed by combining mixed metal oxides and graphitic carbon nitride have gained significant attention in recent years for energy applications. Here, a novel material was obtained by combining ZnV2O6 mixed metal oxide structure synthesized by the solvothermal method with g-C3N4 prepared by pyrolysis. SEM, XPS, XRD, FTIR, and TGA techniques were employed for comprehensive material characterization. The synthesized ZnV2O6/g-C3N4 was then used in supercapacitor studies. The resulting composite material demonstrated a specific capacity of 438 F g−1 at 1.5 A g−1 in 6.0 M KOH solution. After 2500 cycles, it retains 96 % of its capacitance, demonstrating excellent cyclic stability. Furthermore, a symmetric supercapacitor device based on ZnV₂O₆/g-C₃N₄ electrodes was assembled and tested, achieving high capacitance retention over extended charge–discharge cycles. The synergistic effect of g-C3N4, with its large surface area and chemical stability, and ZnV2O6, with its fast electron transfer ability, has resulted in the formation of the composite with enhanced performance. © 2025 Elsevier B.V.