新型可见光活性In_2O_3-CaIn_2O_4复合光催化剂的制备及性能

PREPARATION AND PHOTOCATALYTIC PERFORMANCE OF NOVEL In_2O_3-CaIn_2O_4 VISIBLE-LIGHT-DRIVEN COMPOSITE PHOTOCATALYSTS

通过化学共沉淀法原位合成了新型可见光活性的In_2O_3-CaIn_2O_4复合光催化剂。采用X射线衍射、扫描电子显微镜、电子能谱及紫外-可见漫反射光谱(diffuse reflectance spectroscopy,DRS)等测试手段对复合光催化剂进行了表征。以可见光(波长λ>400nm)为光源,甲基橙染料为目标降解物,考察了In_2O_3-CaIn_2O_4样品的光催化活性。结果表明:通过控制合成温度可得到不同In_2O_3和CaIn_2O_4相对含量的In_2O_3-CaIn_2O_4复合光催化剂,晶粒形貌呈立方体或长方体,粒径随合成温度升高而增加。DRS结果表明:复合光催化剂在可见光区具有良好的吸收性能。In_2O_3-CaIn_2O_4复合光催化剂具有良好的可见光催化活性;15h后,甲基橙的降解率达到了97%。这种新型复合光催化剂的可见光催化活性提高的原因,可能是由于催化剂中复合半导体结构的光生载流子高效分离造成的。

Novel visible-light-driven In2O3-CaIn2O4 composite photocatalysts were synthesized in situ by a chemical co-precipitation method. The composite photocatalysts were characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM）, electron spectroscopy （EDS）, and ultraviolet-visible （UV-Vis） diffuse reflectance spectroscopy （DRS）. The photocatalytic activities of the In2O3-CaIn2O4 samples were evaluated by decolorization of methyl orange under visible light （wavelength 2〉400 nm） irradiation. The results indicate that In2O3-CaIn2O4 composite samples with different In2O3 and CaIn2O4 contents can be obtained by controlling the synthesis temperature. The composite samples consist of cube- or cuboid-like particles, and the diameters of the particles increase with synthesized temperature rising. The DRS spectra illustrate that the composite samples absorb visible light well. The composite samples show superior visible light-induced photocatalytic degradation of methyl orange and the degradation of the methyl orange reaches 97% after irradiation for 15 h. The efficient separation of photo-generated carriers in the composite structure is considered to be the possible reason for the enhanced photocatalytic performance of this composite photocatalyst.