A Novel Method to Fabricate Hierarchical Copper Oxide Photoelectrode and Its Application for Photoelectrochemical Water Splitting

In-situ deposition of cupric oxide (CuO) thin films on fluorine-doped tin oxide is performed through a rapid microwave–assisted method. The duration of microwave (MW) irradiation is optimized in order to prepare efficient and stable photocathodes for photoelectrochemical (PEC) water splitting. We obtain CuO with a unique morphology consisted of intermingled nanosheets. We evaluate PEC performance of the photocathodes through Linear Sweep Voltammetry (LSV) and current stability analyses. The highest achieved photocurrent density is -1.15 mA.cm-2 at 0 V vs. RHE for the sample MW-irradiated for 60 min. This value is comparable or superior to several other CuO-based photocathodes prepared by other chemical-based techniques. The improved properties is attributed to relatively high specific surface area, enhanced capability for light absorption on the photocathode surfaces, and more efficient transfer and/or separation of charge carriers. Hence, it offers our simple method as a promising technique for the preparation of low-cost, photostable photocathodes.