Ionic liquid-assisted electrodeposition synthesis of CuO films

With the global dye pollution situation becoming severe, a highly promising material is needed to purify water to safeguard ecological stability and public health. Studies have shown that semiconductor oxides are capable of generating a large number of photogenerated carriers under visible light irradiation as a way to degrade toxic dyes in wastewater. In this paper, CuO films were synthesized on indium tin oxide-coated glass substrates by ionic liquid-assisted electrodeposition. The samples were characterized by field emission scanning electron microscopy, X-ray diffraction, ultraviolet visible spectrophotometer and energy-dispersive spectrometer. The effects of ionic liquid concentration, electrodeposition parameters and annealing temperature on the structure and properties of CuO films were investigated in detail, as well as an in-depth analysis of the mechanism of the interaction between methylene blue and CuO films. The experimental results show that ionic liquids as reaction media, CuO films modified with ionic liquid have smoother surface and uniform thickness, and their smaller crystal size and uniformly distributed particles can provide more active reaction sites. The CuO film prepared under the optimal conditions has stable absorption and response performance to light, and the degradation rate of methylene blue reached 95% in 180 min, showing good ability to degrade organic matter in wastewater. Therefore, the CuO films prepared by ionic liquid-assisted electrodeposition can be used as an effective photocatalyst for the removal of organic dyes from wastewater to ensure water safety and have potential practical applications for human health.