Nanostructured copper and copper oxide thin films fabricated by hydrothermal treatment of copper hydroxide nitrate

•An α-phase layered hydroxide was used to produce copper oxide thin films.•Metallic copper thin film was also produced by a hydrothermal method.•Nano copper oxide thin films showed tunable band gap and wettability.

Metallic copper and copper oxide thin films were fabricated on surface of glass slide substrates. Copper oxide thin films were prepared by a hydrothermal method using an α-phase layered hydroxide, copper hydroxide nitrate as a precursor. Morphology, thickness and crystallite size of the obtained copper oxide thin films changed by changing the time of hydrothermal treatment. Accordingly, the copper oxide thin films showed various water contact angles and optical band gaps. As, the optical band gap of the nanostructured copper oxide thin films increased with an increase in hydrothermal time from 1.85 to 2.95 eV. Moreover, the water contact angles changed from 16.4 to 38.8° by changing the hydrothermal time. By a reductive hydrothermal-treatment route, the copper oxide thin film was reduced to metallic copper thin film without any particle growth.

Graphical abstractSEM image of copper oxide thin film (inset shows its contact angle image of surface).Figure optionsDownload full-size imageDownload as PowerPoint slide