(Ni-Mo)-TiO2纳米薄膜的制备及其光催化降解罗丹明B的性能

摘要

以恒电流复合电沉积方法制备(Ni-Mo)-TiO2薄膜.采用SEM、XRD和DRS对薄膜的表面形貌、相结构和光谱特性进行表征,以罗丹明B为模拟污染物对薄膜的光催化活性进行测定,讨论罗丹明B溶液的pH值、通入气体以及不同辐射光波对薄膜光催化性能的影响,并推测光催化机理.结果表明:(Ni-Mo)-TiO2薄膜是由TiO2纳米粒子相和纳米晶Ni-Mo固溶体相构成的复合薄膜.薄膜具有较高的光催化活性,在可见光和紫外光照射下,罗丹明B的降解率分别为多孔P25 TiO2粒子薄膜的2.0倍和1.7倍.复合薄膜光催化活性的提高主要源于在薄膜层中能有效形成(Ni-Mo)/TiO2异质结和良好的电子通道,它一方面可以促使光生电荷的分离,另一方面加速了氧气与激发电子的还原反应.%The (Ni-Mo)-TiO2 thin film was prepared by electrolytic co-deposition of Ni-Mo ally and TiO2 particles from a solution in which TiO2 nano particles (P25) were suspended by stirring. The surface morphology, phase structure and optical characteristics of the thin film were analyzed by scanning electron microscopy (SEM), X-ray diffractometry (XRD) and diffuse reflectance ultraviolet-visible spectroscopy (DRS), respectively. The photocatalytic properties were evaluated with Rhodamine B as a model compound. The effects of pH of the Rhodamine B aqueous solution, gaes bubbling through the solution, UV and visible light irradiation on the photocatalytic activity of (Ni-Mo)-TiO2 thin film were investigated. And the photocatalytic reaction mechanism was presumed. The results show that the (Ni-Mo)-TiO2 thin film consists of TiO2 crystalline particles in the size of 50-100nm and Ni-Mo nano crystalline in solid solution. The (Ni-Mo)-TiO2 film is photocatalytically more active than that of TiO2/ITO. Under visible and UV light irradiation, the photocatalytic degradation rate of (Ni-Mo)-TiO2 film is 2.0 times and 1.7 times as much as that of the TiCVTK) thin film, respectively. The increasing photocatalytic activity is mainly due to the heterojunction of (Ni-Mo)/TiO2 and good electronic passage-way in the film, both of which can efficiently promote the separation of charges and accelerate the reaction of excited electrons with oxygen relatively to TiO2/ITO film in photocatalytic degradation for Rhodamine B.