Synthesis of Cu2O-Based Heterostructures and Their Photocatalytic Properties for Water Splitting

We have studied the photocatalytic activity of Cu2O layers on conductive substrates (copper foil and fluorine-doped tin oxide (FTO)) for water splitting. Copper(I) oxide layers on copper foil have been produced by the anodic and chemical oxidation of the foil to copper(II) hydroxide, followed by thermal reduction, and by the hydrothermal oxidation of copper foil directly to Cu2O in an alkaline solution. Cu2O/FTO structures have been produced by Cu2O electrodeposition on FTO substrates from a copper lactate solution. The phase composition and morphology of the resultant photocatalysts have been assessed by X-ray diffraction and scanning electron microscopy. The highest photocatalytic activity has been offered by the sample prepared by the anodic oxidation of a copper plate: j = 1.6 mA/cm2 and η = 2.0%. The results of this study have been used to establish criteria that influence the photocatalytic activity of the materials.