Shifu Chen, Sujuan Zhang, Wei Liu, Wei Zhao
Department of Chemistry, Huaibei Coal Normal College, Anhui, Huaibei 235000, People's Republic of China.
J Hazard Mater. 2008 Jun 30;155(1-2):320-6. doi: 10.1016/j.jhazmat.2007.11.063. Epub 2007 Nov 23.
p-n Junction photocatalyst NiO/TiO2 was prepared by sol-gel method using Ni(NO3)2.6H2O and tetrabutyl titanate [Ti(OC4H9)4] as the raw materials. The p-n junction photocatalyst NiO/TiO2 was characterized by UV-vis diffuse reflection spectrum, X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the photocatalyst was evaluated by photocatalytic reduction of Cr2O7(2-) and photocatalytic oxidation of rhodamine B. The results show that, for photocatalytic reduction of Cr2O7(2-), the optimum percentage of doped-NiO is 0.5% (mole ratio of Ni/Ti). The photocatalytic activity of the p-n junction NiO/TiO2 is much higher than that of TiO2 on the photocatalytic reduction of Cr2O7(2-). However, the photocatalytic activity of the p-n junction photocatalyst NiO/TiO2 is much lower than that of TiO2 on the photocatalytic oxidation of rhodamine B. Namely, the p-n junction photocatalyst NiO/TiO2 has higher photocatalytic reduction activity, but lower photocatalytic oxidation activity. Effects of heat treatment on the photocatalytic activity of p-n junction photocatalyst NiO/TiO2 were investigated. The mechanisms of influence on the photocatalytic activity were also discussed by the p-n junction principle.
采用溶胶-凝胶法，以硝酸镍六水合物（Ni(NO₃)₂·6H₂O）和钛酸四丁酯（Ti(OC₄H₉)₄）为原料制备了p-n结光催化剂NiO/TiO₂。通过紫外-可见漫反射光谱、X射线粉末衍射（XRD）和X射线光电子能谱（XPS）对p-n结光催化剂NiO/TiO₂进行了表征。通过光催化还原Cr₂O₇²⁻和光催化氧化罗丹明B来评估光催化剂的光催化活性。结果表明，对于光催化还原Cr₂O₇²⁻，最佳掺杂NiO的百分比为0.5%（Ni/Ti的摩尔比）。p-n结NiO/TiO₂在光催化还原Cr₂O₇²⁻方面的光催化活性远高于TiO₂。然而，p-n结光催化剂NiO/TiO₂在光催化氧化罗丹明B方面的光催化活性远低于TiO₂。即p-n结光催化剂NiO/TiO₂具有较高的光催化还原活性，但光催化氧化活性较低。研究了热处理对p-n结光催化剂NiO/TiO₂光催化活性的影响。还通过p-n结原理讨论了对光催化活性的影响机制。
