Fig. 3

Electrochemical characterization of anodic nanoporous Au/K_xV₂O₅ microelectrodes. a Representative CV curves of nanoporous Au supported a-K_xV₂O₅, ac-K_xV₂O₅, and c-K_xV₂O₅ (x = 0.25) microelectrodes that are annealed at 25, 200, and 300 °C, respectively. Scan rate: 50 mV s⁻¹; electrolyte: 0.5 M K₂SO₄. b Volumetric capacities of nanoporous Au/K_xV₂O₅ (x = 0.25) microelectrodes with the constituent a-K_xV₂O₅, ac-K_xV₂O₅, and c-K_xV₂O₅ (annealed at 25, 200, and 300 °C) at various scan rates from 5 to 1000 mV s⁻¹. c Representative CV curves of nanoporous Au/ac-K_xV₂O₅ (x = 0, 0.1, 0.2, and 0.25) microelectrodes that are annealed at 200 °C. scan rate: 50 mV s⁻¹; electrolyte: 0.5 M K₂SO₄. d EIS spectra of nanoporous Au/ac-K_xV₂O₅ (x = 0, 0.1, 0.2, and 0.25) microelectrodes annealed at 200 °C