Nanoporous PtAg and PtCu alloys with hollow ligaments for enhanced electrocatalysis and glucose biosensing

Nanoporous silver (NPS) and copper (NPC) obtained by dealloying AgAl and CuAl alloys, respectively, were used as both three-dimensional templates and reducing agents for the fabrication of nanoporous PtAg (NPS-Pt) and PtCu (NPC-Pt) alloys with hollow ligaments by a simple galvanic replacement reaction with H2PtCl6. Electron microscopy and X-ray diffraction characterizations demonstrate that NPS and NPC with similar ligament sizes (30–50 nm) have different effects on the formed hollow nanostructures. For NPS-Pt, the shell of the hollow ligament is seamless. However, the shell of NPC-Pt is comprised of small pores and alloy nanoparticles with a size of ∼3 nm. The as-prepared NPS-Pt and NPC-Pt exhibit remarkably improved electrocatalytic activities towards the oxidation of ethanol and H2O2 compared with state-of-the-art Pt/C catalyst, and can be used for sensitive electrochemical sensing applications. The hierarchical nanoporous structure also provides a good microenvironment for enzymes. After immobilization of glucose oxidase (GOx), the enzyme modified nanoporous electrode can sensitively detect glucose in a wide linear range (0.6–20 mM).

► Nanoporous PtAg and PtCu alloy with hollow ligaments are fabricated using nanoporous Ag and Cu as both templates and reducing agents.
► The shell of the nanoporous PtAg ligaments is seamless, while that of nanoporous PtCu is comprised of small pores and alloy nanoparticles.
► Nanoporous PtAg exhibits enhanced electrocatalytic activity and sensing performance compared with nanoporous PtCu.