N-doped reduced graphene oxide/ZnO/nano-Pt composites for hydrogen peroxide sensing

An effective non-enzymatic H 2 O 2 sensor electrode was fabricated, including nitrogen doped reduced graphene oxide (N-rGO) modified with different amounts of ZnO and incorporated by Pt nanoparticles. ZnO and Pt were fabricated on N-rGO with a hybrid synthesis consisting of hydrothermal and chemical synthesis. The Pt–N-rGO, Pt–10ZnO@N-rGO, Pt–20ZnO@N-r byGO and Pt–40ZnO@N-rGO composites as well as the effect of ZnO amount on the catalysts were studied the SEM (Scanning Electron Microscopy), EDX (Energy Dispersive X-ray Spectroscopy), TEM (Transmission Electron Microscopy), BET (Brunauer–Emmett–Teller method), XRD (X-ray Powder Diffraction). The electro-catalytic activity of the samples for H 2 O 2 reduction was investigated by cyclic voltammetry, electrochemical impedance spectroscopy and the amperometric method. Among the prepared catalysts, Pt–40ZnO@N-rGO was found to have higher sensitivity toward the reduction of H 2 O 2 at ‒ 0.6 V (Ag/AgCl) because of the synergistic effect between ZnO and Pt nanoparticles that synthesized with the optimum mass ratio. It showed a linear response range from 0.1 μM to 0.1 mM with a low detection of 0.109 μM and a high sensitivity of 557 μA/mM −1 . Furthermore, the fabricated sensor presented good selectivity to H 2 O 2 with the existence of other interfering species. • Synthesized successfully of non-enzymatic H 2 O 2 electrochemical sensor based on N-rGO loaded with Pt and ZnO nanoparticles onto GCE. • Examined catalytic performance of ZnO nanoparticles toward H 2 O 2 reduction. • Fabricated electrode presented a good selectivity to H 2 O 2 with the presence of other interfering species.