熔盐法制备立方块状钛酸锶及其表面铜离子团簇修饰

Preparation of SrTiO_3 Cubes by Molten Salt Method and Its Surface Ions Modification with Cu(II) Clusters

采用熔盐法制备了钙钛矿结构的钛酸锶立方块。通过浸渍法对所得钛酸锶进行表面离子修饰,得到表面负载无定形Cu(II)纳米团簇的新型可见光催化剂。利用ICP-AES、XRD、SEM、XPS、DRS等对其进行表征。通过光催化降解气相异丙醇对其可见光催化活性进行评价。研究发现,负载无定形Cu(II)团簇后,所得的催化剂Cu(II)-SrTiO3具有较好的可见光催化降解气相异丙醇的性能,能够有效地将异丙醇彻底矿化成二氧化碳。

Pure SrTiO3 cubes with perovskite structure were prepared by a molten salt method. The novel visible light active photocatalysts were obtained as a result of surface modification of SrTiO3 cubes with Cu ions by an impregna- tion technique. The as-prepared samples were characterized by an inductively coupled plasma atomic emission spec- trometer, X-ray diffraction （XRD）, scanning electron microscope （SEM）, X-ray photoelectron spectroscope （XPS）, and UV-Vis diffuse reflectance spectroscope （DRS）. The decomposition of gaseous 2-propanol was chosen as a probe to evaluate the photocatalytic activities of the samples in air. The results show that the visible light photocatalytic activi- ties of the samples can be significantly enhanced by grafting amorphous Cu（II） clusters on the surfaces of SrTiO3. Un- der visible light irradiation, electrons in the valance band of SrTiO3 are transferred to the surfaced Cu（II） clusters, leaving holes with strong oxidizing power in the valance band and producing Cu（I） clusters. The Cu（I） clusters can ef- ficiently reduction oxygen molecules via a multi-electron reduction process to consume the excited electrons. On the other hand, the generated holes can decompose the organic compounds. As a result, the complete decomposition of gaseous 2-propanol into CO2 can be achieved over the Cu（II）-SrTiO3 under visible light irradiation.