Free-standing Pt nanowire networks with clean surfaces: Highly sensitive electrochemical detection of nitrite

- Pt NWNs are synthesized by a one-pot aqueous method only with hydrogen bubbles as the dynamic template.
- There is no any structure director, seed, template or polymer involved.
- The architectures show excellent catalytic activity toward nitrite oxidation.
- The nitrite sensor exhibits high selectivity, sensitivity and stability.

Support-free interconnected Pt nanowire networks (Pt NWNs) were fabricated by rapidly pouring sodium borohydride (NaBH4) solution into the Pt precursor solution, where hydrogen bubbles were in situ generated from hydrolysis and oxidation of NaBH4 as a dynamic template. There was no any capping agent, surfactant, seed, polymer, or special experimental device involved. The morphology, composition and structure of the samples were mainly characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The architectures displayed highly electrocatalytic behavior toward nitrite oxidation and wide linear ranges of 1.0 μM-24.0 mM and 24.0-132.0 mM, together with high sensitivity (16.94 and 4.34 μA mM− 1) and low detection limit (0.14 μM, S/N = 3). It demonstrated the improved electroanalytical performance for nitrite determination because of the unique free-standing Pt nanostructures with clean surfaces.

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