CuAlO2的合成及其复合催化剂的光催化性能

以硝酸铜和硝酸铝为原料,草酸为铜离子的沉淀剂,半湿法制得前驱体,再于氮气气氛下热处理形成了铜铁矿结构的CuAlO2。对样品进行热失重(TG),X射线衍射(XRD),紫外-可见漫反射(UV-Vis-DR)及透射电镜(TEM)表征分析,探讨了CuAlO2的形成过程。结果显示,随着热处理温度的升高,含铜物质经历了由CuO、Cu2O到CuAl2O4,再到CuAlO2的变化历程;制得的CuAlO2晶体结晶完整性较好,直接禁带宽度为3.1 eV左右。用沉淀复合的方法制备出了n-p异质复合型光催化剂WO3-CuAlO2、TiO2-CuAlO2和ZnO-CuAlO2,对复合催化剂进行了XRD和TEM表征分析,并测试了复合催化剂的光催化活性。结果表明,上述催化剂均由两种物相复合而成,且在紫外光的照射下均可分解纯水放出氢气。

Preparation of CuAlO2 and Photocatalytic Performance of Composite Catalysts

Delafossite CuAlO₂ is prepared by thermal treatment the precursor obtained via a semi-wet method using Cu(NO₃)₂ and Al(NO₃)₃ as raw material ,and oxalic acid as precipitant of copper ion under nitrogen atmosphere. The samples are characterized by thermal gravimetric analysis(TG), X-ray diffraction (XRD), ultraviolet visible diffuse reflectance(UV-Vis-DR) and transmission electron microscope(TEM). The formation process of the CuAlO₂ is researched. With increasing the thermal treatment temperature of the precursor, firstly the CuO and Cu₂O are generated, and then intermediate phase of CuAl₂O₄ appeared, finally no impurity phase CuAlO₂ formed. The results shows that the synthesized CuAlO₂ has good crystal perfection and its direct band gap is about 3.1 eV. The n-p composite photocatalysts WO₃-CuAlO₂, TiO₂-CuAlO₂ and ZnO-CuAlO₂ are prepared by precipitation composite method. The composite photocatalysts are characterized by XRD and TEM, and the photocatalytic performance of the catalysts are tested, and the results indicate that all the composite catalysts mentioned above are all made up two phases, and they all have photocatalytic activity for decomposing pure water into hydrogen under the UV-light irradiation.