Synthesis of Ag@Pt core–shell nanoparticles loaded onto reduced graphene oxide and investigation of its electrosensing properties

Abstract

An Ag–graphene nanocomposite was firstly prepared using a one-step thermal reduction, then an Ag@Pt core–shell nanostructure was obtained via a galvanic replacement reaction. The Ag@Pt–graphene nanocomposite was successfully synthesized and further fabricated into an electrochemical sensor of H₂O₂. Its electrochemistry and electrocatalytic behavior towards H₂O₂ were investigated. The results exhibited that this sensor had excellent electrocatalytic properties towards H₂O₂. The reduction peak current signals had a good linear dependence on H₂O₂ concentration in the range from 5.0 μmol L⁻¹ to 12.4 mmol L⁻¹, and the detection limit was 0.9 μmol L⁻¹ (S/N = 3). The preparation method is environmentally friendly and can make Ag, Pt and graphene nanomaterials become a unified whole, introducing a synergistic effect between the nanoparticles effectively, leading to a superior electrocatalytic ability compared to GO or the Ag–graphene nanocomposite. The results indicate that the Ag@Pt–graphene nanocomposite has great application potential for use in electrochemical sensors.