Photocatalytic Enhancement of a Novel Composite CuAl<inf>2</inf>O<inf>4</inf>/TiO<inf>2</inf>/CuO Films Prepared by Sparking Process

Abstract

© 2020 Elsevier GmbH A novel composite CuAl2O4/TiO2/CuO films were successfully deposited on quartz substrate using a simple and low-cost sparking process. The as-deposited films were then annealed at 300, 700 and 1100 °C for 1 h under atmospheric pressure. Morphology, structural and optical properties were characterized by SEM, TEM, XRD, XPS and UV/vis spectroscopy. The results show the nanoparticles with size of 20-50 nm deposited and aligned as a network on the substrate. The number of particles decreased with increased annealing temperature. Meanwhile, SAED and XRD patterns of the annealed films at 700 °C consisted of CuO, CuAl2O4 and rutile TiO2 phases. Interestingly, double band gap of 3.50 eV and 2.56 eV were obtained in the annealed films at 700 °C. The photocatalytic activity of CuAl2O4/TiO2/CuO films annealed at 700 °C was optimized condition. This is because the double band gap composite films can reduce the e−/h+ pair recombination. Therefore, novel composite films after annealing at 700 °C can improve the photocatalytic efficiency under visible light.