Cuprous oxide/silver (Cu₂O/Ag) nanocomposites were prepared via a facile one-step method and used to construct an electrochemical sensor for hydrogen peroxide (H₂O₂) detection. In this method, AgNO₃ and Cu(NO₃)₂ were reduced to Cu₂O/Ag nanocomposites by glucose in the presence of hexadecyl trimethyl ammonium bromide (CTAB) at a low temperature. The optimum condition was the molar ratio of silver nitrate and copper nitrate of 1:10, the temperature of 50 °C. Under this condition, Cu₂O/Ag nanocomposites were obtained with uniformly distributed and tightly combined Cu₂O and Ag nanoparticles. The size of Cu₂O particles was less than 100 nm and that of Ag particles was less than 20 nm. Electrochemical experiments indicate that the Cu₂O/Ag nanocomposites-based sensor possesses an excellent performance toward H₂O₂, showing a linear range of 0.2 to 4000 μM, a high sensitivity of 87.0 μA mM-1 cm-2, and a low detection limit of 0.2 μM. The anti-interference capability experiments indicate this sensor has good selectivity toward H₂O₂. Additionally, the H₂O₂ recovery tests of the sensor in diluted milk solution signify its potential application in routine H₂O₂ analysis.
Keywords: cuprous oxide/silver; electrochemistry; hydrogen peroxide; nanocomposites; sensor.