论文部分内容阅读
采用机械球磨法成功制备Ag_3PO_4/MoS_2纳米片复合催化剂。运用X射线衍射仪(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、紫外可见漫反射光谱(UV-Vis)和荧光发射光谱(PL)对复合催化剂的结构和形貌进行了表征。结果表明,Ag_3PO_4纳米粒子均匀地附着在MoS_2纳米片层结构上,两者形成紧密结合。以亚甲基蓝为模拟污染物,研究复合催化剂在可见光照射下的光催化特性;通过循环实验考察复合催化剂的稳定性。结果显示,含有1%的MoS_2纳米片与Ag_3PO_4形成的复合催化剂在30 min内对亚甲基蓝的降解率为95%,其降解动力学常数是纯相Ag_3PO_4的2倍。经过5次循环实验后复合催化剂对于亚甲基蓝的降解率为84%,而纯Ag_3PO_4对于亚甲基蓝的降解率仅为35%。Ag_3PO_4/MoS_2纳米片复合催化剂具有优良的光催化活性和高稳定性,主要归因于二硫化钼纳米片与磷酸银形成异质结,磷酸银激发的电子和二硫化钼纳米片产生的空穴直接复合,从而促使光生电子从磷酸银晶体表面快速分离,减轻了磷酸银的光电子腐蚀,同时也提高了复合物的光催化活性。
Ag_3PO_4 / MoS_2 nanosheet composite catalyst was successfully prepared by mechanical milling. The structure and morphology of the composite catalyst were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-visible diffuse reflectance spectroscopy and fluorescence emission spectroscopy Characterization. The results show that Ag 3 PO 4 nanoparticles are uniformly attached to the MoS 2 nanosheet structure and form a tight bond between the two. With methylene blue as a simulated pollutant, the photocatalytic activity of the composite catalyst under visible light irradiation was studied. The stability of the composite catalyst was investigated by cyclic experiments. The results showed that the composite catalyst containing 1% MoS_2 nanoplatelets and Ag_3PO_4 formed a 95% degradation rate of methylene blue in 30 min, and its degradation kinetic constant was twice that of pure Ag_3PO_4. After 5 cycles, the degradation rate of the composite catalyst to methylene blue was 84%, while the degradation rate of pure Ag 3 PO 4 to methylene blue was only 35%. Ag_3PO_4 / MoS_2 nanosheet composite catalyst has excellent photocatalytic activity and high stability, mainly due to the formation of heterojunction of molybdenum disulfide nanosheets with silver phosphate, silver phosphate excited electrons and holes generated by molybdenum disulfide nanosheets Direct recombination, which led to the rapid separation of photogenerated electrons from the surface of silver phosphate crystals, which reduced the photoelectron corrosion of silver phosphate and enhanced the photocatalytic activity of the composite.