Antibacterial and photocatalytic properties of SiO2-CuxO films with high copper loading and crystallized CuxO nanoparticles

SiO2-CuxO composites may have potential applications in antibacterial and dye degradation. However, it is still a challenge to prepare SiO2-CuxO films with well crystallized CuxO nanoparticles and high Cu/Si molar ratios under alkaline condition at relatively low temperature. Herein, by using PVP stabilized alkaline silica sol and ethanolic solution of copper acetate, a series of SiO2-CuxO composite films with high Cu/Si molar ratios were successfully prepared via a facile two-step process of dip coating and annealing. The microstructure and crystalline phase of the composite films were finely controlled by changing the amount of PVP, the concentration of copper solution and the calcination temperature. The results showed that film prepared with 1 mol/L copper acetate solution and calcined at 500 °C exhibited the best antibacterial activity, adsorption and photocatalytic performance toward methylene blue in solutions. The prepared films could be conveniently used in antibacterial field and the treatment of organic wastewater.