Application of orthogonal experiments in preparation of Cu-Ce/TiO2 nano-particles composite photocatalyst

In this paper, Cu-Ce/TiO₂ nano-particles were synthesized by sol-gel method with copper nitrate Cu(NO₃)₂·3H₂O, cerium nitrate Ce(NO₃)₃·6H₂O, and Ti(C₄H₉O)₄. Their photocatalytic activities were evaluated by degrading formaldehyde gas under visible light irradiation. The photocatalytic activity of Cu-Ce/TiO₂ nano-particles, in the visible light, is influenced by Cu-Ce-doped loading (A factor), Cu-Ce molar ratio (B factor) and sintering temperature (C factor) in the process of preparation. With orthogonal layout L₁₆(4⁵), the orthogonal experiments were employed to optimize the conditions for preparation of composite photocatalyst, of which the photocatalysis was analyzed and compared by range analysis. According to the results, the effectiveness of every factor which could affect degrading ability to the photocatalysis of Cu-Ce/TiO₂ nano-particles was presented respectively. That is, Cu-Ce-doped loading is the most important factor with Cu-Ce molar ratio the second one and sintering temperature the third one orderly. Finally, it is suggested that the optimum scheme for the preparation of the composite photocatalyst is A₃B₃C₂ (A₃=3%, B₃=1:1 and C₂=500°C).