Electrochemical synthesis and characterization of ZnO/ERGO/ITO nanocomposite electrodes

Hierarchical flower-like ZnO/electroreduced graphene oxide (ZnO/ERGO) nanocomposites were synthesized on the ITO electrode surface for the first time through electrochemical co-deposition method from a aqueous mixture containing graphene oxide (GO) and Zn2+ ions at room temperature. During the formation of hierarchical flower-like ZnO nanostructures by one-step cathodic electrochemical deposition, the graphene oxide was electrochemically reduced to graphene simultaneously. The morphological and structural properties of the ZnO/ERGO composites were characterized by Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Energy dispersive X-ray analysis (EDX), Raman spectroscopy and photocurrent measurement. Due to rapid charge transport in the composite materials and the highly crystalline structure of flower-like ZnO/ERGO, the photocurrent responses are exhibited fast and uniform. The electrochemical performance of the ZnO/ERGO composite modified ITO was investigated by amperometric technique, and the resulting electrode displays excellent performance towards hyrogen peroxide (H2O2) at -700 mV in the linear response range from 3,7 to 66,6 μM, with correlation coefficient of 0,9962 and short response time (<5 s). Results show that the ZnO/ERGO composites exhibited a remarkably enhanced electrocatalytic efficiency compared to pure ZnO flowers. The cause of the enhanced electrocatalytic performance could be ascribed to the synergistic effect between ZnO flowers and ERGO sheets.