Decorating Cu2O with Copper Metal (Cu) through Facile Electrochemical Deposition for Methylene Blue Degradation

Cuprous oxide (Cu2O) thin film was decorated with copper metal (Cu) by the simple electrochemical deposition method. This study was motivated to improve the role of Cu as a co-catalyst due to the narrow band gap energy of known photocatalyst Cu2O. Cu was electrodeposited on Cu2O thin film with a substrate of indium tin oxide (ITO) at a voltage of -0.3V and a temperature of 60 °C in CuSO4 (pH 10) under a magnetic stirrer. The structure, phase, and morphology of Cu2O/Cu were characterised by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The electrocatalytic performance of Cu2O/Cu was recorded using linear sweep voltammetry and electrochemical impedance spectroscopy. XRD and SEM results show Cu was successfully deposited covering Cu2O. The current density of Cu2O/Cu increased by 2.7041 mA/cm2 confirming the lower charge current resistance of 2.48 kΩ. The Cu-decorated Cu2O demonstrated an improved photocatalytic activity, as shown by the increase of MB degradation from 46.33% to 50.87%. It was believed from characterisations that Cu deposition leads to more dense carriers and charge transfer, hence higher photocatalytic activity towards MB degradation than bare Cu2O thin film.