施主掺杂对BaTiO3钙钛矿半导体纳米晶光催化性能的影响

以沉淀法制备的Cu_2O为牺牲模板剂,采用水热法制备La施主掺杂的BaTiO_3钙钛矿半导体纳米晶,借助X射线衍射(XRD)、透射电子显微镜(TEM)、高分辨透射电镜(HRTEM)、X射线光电子能谱((XPS)、扫描电子显微镜(SEM)、紫外-可见漫反射光谱(UV-Vis DRS)表征La掺杂的BaTiO_3晶的物相、微观形貌及光催化性能。结果表明,La掺杂BaTiO_3构建了晶体缺陷,有效提高了BaTiO_3的光催化性能。当掺杂量为4%(w/w)时,样品的光催化性能最好,在可见光照射360 min后,对4-硝基苯酚溶液的降解率可达到93.2%。该催化剂5次循环后的活性仍然大于86.7%,表明La施主掺杂的BaTiO_3是一种有效的可见光催化剂。

Effects of Donor-Doped on Photocatalytic Properties of BaTiO3-Based Nanoparticle

Cu₂O was synthesized by chemical precipitation, La doped BaTiO₃-based powders were synthesized via a hydrothermal method using the Cu₂O as the sacrifice template. The structure, morphology and visible light properties have been characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), high-resolution transmission electron microscope (HR-TEM), X-ray photoelectron spectroscopy (XPS), scanning electron micro-graphs (SEM), UV-Vis diffuse reflectance spectrophotometer (UV-Vis DRS). The results showed that the doping of La³⁺ increased the conductivity and made the range of photo-response broadened, which reduced the band gap of the semiconductor and accelerated the separation of photo-generated electron hole pairs. The surface defects were induced with a facile and effective approach by La³⁺ ion doping, and the photocatalytic performance of BaTiO₃ was improved. However, as the doping amount of La³⁺ ions increased, the band gap of the semiconductors decreased and the redox ability of the phototgenerated electrons and holes deceased when the dopant was excessive. When the doping amount was 4%(w/w), the photocatalytic performance of the sample was the best, and the degradation efficiency of 4-nitrophenol was 93.2% after 360 min visible light irradiation. The decomposition rate of 4-nitrophenol was still above 86.7% even after 5 cycles, thus artificial catalytic defects of La donor-doped BaTiO₃-based nanoparticle could effectively improve the photocatalytic properties.