Hierarchical nested-network porous copper fabricated by one-step dealloying for glucose sensing

• Freestanding hierarchical nested-network porous copper (HNNPC) was fabricated.
• The Al75Cu25 alloy had both pure Al phase and the intermetallic Al2Cu phase.
• HNNPC has both larger ligaments at micron scale and smaller ligaments at nanoscale.
• CV and EIS of HNNPC presented excellent electro-catalytic sensitivity to glucose.

A novel freestanding hierarchical nested-network porous copper (HNNPC) was fabricated by one-step free dealloying. The Al75Cu25 (at.%) alloy precursor was prepared with both pure Al phase and the intermetallic Al2Cu phase. The microstructure of the alloy led to the hierarchical porous structure characterized by larger ligaments (pores) at micron scale (ca. 3–5 μm) and the smaller ligaments (pores) at nanoscale (ca. 50–60 nm) through dealloying. The morphology, crystal structure, elemental analysis, surface area, pore sizes distribution, electrochemical and sensing properties of HNNPC have been studied. The resulted HNNPC had bicontinuous hierarchical structure, which met the electrochemical or chemical applications’ requirements, namely, (1) the larger pores providing rapid transport pathways for fast switching and (2) smaller pores at nanoscale having the large surface area for functionalization. The CV and EIS of HNNPC presented an electro-catalytic activity to glucose, which was promising as a glucose sensor with excellent sensitivity. Furthermore, HNNPC itself could also be a host of other active materials.