Abstract
Well-defined mesoporous Ag-doped Co3O4 nanosheets (NSs) has been synthesized directly on Ni-foam (NF) via a facile hydrothermal and post-annealing approach. The tune bandgap and improved electrical conductivity of the Ag-doped Co3O4 sample are confirmed by UV–visible spectroscopy and two probe current-voltage (I–V) measurements. The Ag-doped Co3O4 sample exhibits a higher surface area (176 m2g-1) than that of the pristine Co3O4 sample (108 m2g-1). The Ag-doped Co3O4/NF based electrode shows superior specific capacitance of 1425 Fg-1 at 1 Ag-1 and outstanding rate capability as it retains 92.84% of its initial specific capacitance (at 1 Ag-1) even at higher the current density of 10 Ag-1. Moreover, the specific capacitance of the material increases up to 104.7% of its initial capacitance for the first 2000 cycles, and then it gradually decreases to 96.4% after 5000 cycles. In fact, the superior electrochemical properties of the mesoporous Ag-doped Co3O4 nanosheets are attributed to its tuned bandgap, improved specific surface area, mesoporous architecture, and binder-free design. The electrochemical results revealed that the mesoporous Ag-doped Co3O4 NSs can be used as potential electrode material in the high-performance electrochemical capacitor.
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•Mesoporous Ag-doped Co3O4 nanosheets were fabricated via facile route.•The fabricated electrode exhibited 1425 Fg-1 specific capacitance at 1 Ag-1.•The electrode retained 96.4% of its initial capacitance after 5000 cyclic tests.