Hydrogen peroxide sensing using Cu2O nanocubes decorated by Ag-Au alloy nanoparticles

To develop the high efficiency nonenzymatic hydrogen peroxide (H2O2) sensor, Cu2O nanocubes decorated by Ag-Au alloy nanoparticles (Ag-Au/Cu2O nanocomposites) were designed and synthesized in this paper. By studying for the electrocatalytic activities toward H2O2 reduction, the as-prepared Ag-Au/Cu2O nanocomposites exhibited higher performance toward electrochemical oxidation of H2O2 in 0.2 M phosphate buffered saline (PBS) solution than pristine Cu2O nanocubes, Ag-Cu2O and Au-Cu2O nanocomposites, and the detection limit was 1.30 μM and the sensitivity was 4.16 μA cm−2 mM−1, respectively. The enhanced electrochemical activity of Ag-Au/Cu2O nanocomposites indicated that the Ag-Au alloys dispersed on the surface of Cu2O played a key role in the sensing properties enhancement, and the possible mechanisms for the enhanced electrochemical activity of Ag-Au/Cu2O nanocomposites have been detailed discussed. In addition, the anti-interference capability experiment indicated that the Ag-Au/Cu2O nanocomposites have good selectivity toward H2O2. The excellent performance demonstrated the potential application of the Ag-Au/Cu2O nanocomposites for H2O2 detection.