Preparation of three-dimensional ordered macroporous Cu₂O film through photonic crystal template-assisted electrodeposition method

Three-dimensional ordered macroporous (3DOM) Cu₂O film was prepared on indium-tin-oxide (ITO) glass using photonic crystal template-assisted electrodeposition approach. The technological process involved the following steps: preparation of three-dimensional (3D) photonic crystal template, potentiostatic electrodeposition of Cu₂O into the template, and template removal. 210 nm polystyrene (PS) spheres were used to prepare the 3D photonic crystal template by means of a vertical deposition technique on ITO glass. A two-electrode cell was used for electrodeposition, in which the anode was graphite and the cathode was PS-coated ITO glass. The electrodeposition solution consisted of 0.1 M sodium acetate and 0.02 M copper acetate and was acidified at pH 5.7. Via electrodeposition, the interstitial space of the packed PS photonic crystal template was filled with Cu₂O. After removal of the PS photonic crystal template by immersing in tetrahydrofuran solution, 3DOM Cu₂O film with a homogeneous area of 20 × 10 mm² was obtained. The film was characterized by field emission scanning electron microscopic (FE-SEM) and X-ray diffraction. The results indicated that the as-prepared Cu₂O film was of high purity, good homogeneity, and a well-ordered macroporous structure.