Phosphidated tungsten oxide@polyaniline hybrid electrode on nickel foam for dual-function supercapacitor and methanol oxidation

In this study, a novel hybrid electrode of phosphidated tungsten oxide (WO₃-P) and polyaniline (PANI) is synthesized on a nickel foam substrate (PANI@WO₃-P/NF). The hierarchical structure combines the pseudocapacitive properties of WO₃-P with the high conductivity and redox activity of PANI, while the 3D porous nickel foam enhances electron transport and electrolyte access. The synergistic PANI@WO₃-P interaction significantly improves the electrochemical performance, delivering a specific capacity of 1210 C g^{- 1} at 1 A g^{- 1} and retaining 90.85% capacitance after 10,000 cycles, ideal for energy storage. Asymmetric two-electrode device achieves an energy density of 60.44 Wh kg⁻¹ at 1 A g⁻¹ with a power density of 637.21 W kg⁻¹, underscoring its supercapacitor (SC) potential. In addition, platinum (Pt) electrodeposition enhances the catalytic activity of the PANI@WO₃-P/NF electrode for methanol oxidation, paving the way for advanced energy conversion in next-generation direct methanol fuel cells. The maximum current density reaches 19.85 mA mg⁻¹ Pt, and the electrode retains 80.64% of its original activity even after 1000 cycles, demonstrating that the Pt/PANI@WO-P/NF electrode has good stability. This versatile dual-functional hybrid electrode platform uniquely combines high-performance Pt-free supercapacitor behavior with remarkable electrocatalytic MOR activity achieved through minimal Pt modification, highlighting its potential for advanced multifunctional energy applications.