Manganese dioxide based ternary nanocomposite for catalytic reduction and nonenzymatic sensing of hydrogen peroxide

In this study, a ternary nanocomposite Au –MnO2–rGO composed of gold nanoparticles (Au NPs), manganese dioxide nanorods (MnO2 NRs) and reduced graphene oxide nanosheet (rGO) was synthesized for the catalytic reduction and nonenzymatic sensing of hydrogen peroxide (H2O2). The composite Au–MnO2–rGO was characterized by SEM, TEM, XRD and electrochemical methods. It was found the integration of MnO2 NRs with rGO could enhance the attachment of MnO2 NRs on the electrode and improve its conductivity. Subsequent decoration of Au NPs, further improved the performance for the reduction of H2O2. Greatly enhanced catalysis was observed on the ternary nanocomposite due to the synergistic interactions among MnO2 NRs, rGO and AuNPs. Based on this Au–MnO2–rGO composite, a new nonenzymatic H2O2 sensor with a wide linear range (0.1–22 μM and 0.022–12.6 mM), low detection limit (0.05 μM), high sensitivity (980 μA/mM/cm2), good stability and negligible interference from ascorbic acid was successfully fabricated.