Three-dimensional nanoporous copper with tunable structure prepared by dealloying titanium–copper–cobalt metallic glasses for supercapacitors

Three-dimensional bicontinuous nanoporous copper (NPC) with a pore size of 10–60 nm was fabricated by dealloying titanium–copper–cobalt amorphous ribbons in 0.23 M hydrofluoric acid (HF) solution for 1–12 h. It is found that dealloyed ribbons show sandwich-like layered structure in the cross-section and the pore size in the outer layer is larger than that in the core layer. The NPC ribbons, polarised in 1 M potassium hydroxide (KOH) solution for 30 min, delivered an excellent electrochemical performance with a specific capacitance of 202.3 mF/cm² at the current density of 5 mA/cm² in 1 M KOH electrolyte and good cycling stability of 90% capacitance retention after 5000 cycles at 20 mA/cm².