Photocatalytic efficiency under visible light of a novel Cu-Fe oxide composite films prepared by one-step sparking...

Copper-iron (Cu-Fe) oxide composite films were successfully deposited on quartz substrate by a facile sparking process. The nanoparticles were deposited on the substrate after sparking off the Fe and Cu tips with different ratios and were then annealed at different temperatures. The network particles were observed after annealing the film at 700 °C. Meanwhile, XRD, XPS and SAED patterns of the annealed films at 700 °C consisted of a mixed phase of CuO, γ-Fe₂O₃, CuFe₂O₄ and CuFe₂O. The film with the lowest energy band gap (E_g) of 2.56 eV was observed after annealing at 700 °C. Interestingly, the optimum ratio and annealing temperature show the photocatalytic activity under visible light higher than 20% and 30% compare with the annealed TiO₂ at 500 and 700 °C, respectively. This is a novel photocatalyst which can be replaced TiO₂ for photocatalytic applications in the future.