A Novel Nonenzymatic Hydrogen Peroxide Sensor Based on Electrocodeposition of Copper and Silicomolybdate on Multi-Walled Carbon Nanotubes

Novel copper and silicomolybdate (SiMO) decorated multi-walled carbon nanotubes (Cu/SiMO/MWCNT) has been fabricated for the detection of hydrogen peroxide (H2O2). The Cu/SiMO/MWCNT can be prepared by the electrocodeposition of copper and silicomolybdate on a MWCNT modified electrode. As prepared hybrid composite was characterized by X-ray diffraction and scanning electron microscopy. The composite modified electrode shows good catalytic activity towards reduction of H2O2 with low overpotential (-0.16 V) and high sensitivity than that obtained using Cu, MWCNT, Cu/MWCNT, and Cu/SiMO modified electrodes. The maximum current response of the hybrid composite for H2O2 reduction was found at pH 1 than that of other pH. Amperometric response shows that the catalytic response of the composite was in the linear range of 6.53x10(-6)-5.2x10(-3) M with high sensitivity of 650 mu A mM(-1) cm(-2) and response time of 5 s for the detection of H2O2. The detection limit was estimated as 6.53x10(-6) M (S/N = 3). The Cu/SiMO/MWCNT composite electrode is not influenced by potential interferents and can be a good electrocatalyst for a nonenzymatic H2O2 sensor due to its low overpotential, high sensitivity, low detection limit, fast response, good stability, good selectivity, and simple method.