▎ 摘　　要

A series of ZnFe2O4/graphene nanoplatelets ((ZF)(1-x)(GNPs)(x)) nanocomposites have been synthesized and characterized. By optimizing the weight ratio of graphene nanoplatelets (GNPs), the synthesized nanocomposites have been identified as an excellent material for electrochemical capacitors with outstanding electrochemical capacitance (314 Fg(-1) at 0.5 Ag-1), high rate performance, and long-standing cyclic stability (77.6% retention). The enhanced electrochemical performance might be adduced to the improved electrode/electrolyte charge transfer interface and conducting nature of GNPs. Besides, (ZF)(1-x)(GNPs)(x) nanocomposites exhibit outstanding visible light driven photocatalytic efficiency for the removal of methylene blue (MB) dye in water i.e., 97.46% of the MB is degraded in 70 min, which can be primarily ascribed to the enhanced photo Fenton reaction, effective electron-hole (e(-)/h(+)) separation and strong interfacial coupling between ZnFe2O4 nanoparticles (ZF NPs) and GNPs. Our results offer new insights into multifunctional nanocomposites for the electrochemical energy storage and treatment of polluted wastewater.