【摘要】 采用浸渍还原法成功将金铜纳米颗粒负载到锌铝水滑石表面(AuCu/ZnAl-LDHs),焙烧制得复合金属氧化物(AuCu/ZnAlLDO)。通过X射线粉末衍射(XRD)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和紫外-可见漫反射光谱(UV-Vis DRS)技术对材料的晶型、形貌、元素组成以及光吸收性能进行分析。以邻苯二酚为降解物,研究AuCu/ZnAl-LDO在可见光下的光催化性能。实验结果显示:相比于纯锌铝复合金属氧化物(ZnAl-LDO),AuCu/ZnAl-LDO具有更强的可见光吸收能力。Au、Cu负载比例为5∶1,焙烧温度为400℃的催化剂在5 h内对邻苯二酚的降解率为94.5%,其降解的反应速率常数为ZnAl-LDO的13.4倍。此外,借助理论计算推测了AuCu/ZnAl-LDO电子转移的路径,并以此提出可能的光催化降解机理。更多还原

【Abstract】 Gold and copper nanoparticles were supported on the surface of zinc-aluminum layered double hydroxides(AuCu/ZnAl-LDHs) by method of impregnation-reduction. Mixed metal oxides(AuCu/ZnAl-LDO) were obtained from AuCu/ZnAl-LDHs after calcination. The as-prepared photocatalysts were well characterized by powder X-ray diffraction(XRD), transmission electron microscopy(TEM), X-ray photoelectron spectroscopy(XPS)and UVVis diffuse reflectance spectroscopy(UV-Vis DRS) to investigate the crystal structures, microstructure,elemental composition and visible light absorption capability. The photocatalytic performance of AuCu/ZnAl-LDO was studied by degradation of catechol under visible Light. The results of experimental indicated that AuCu/ZnAl-LDO had stronger visible light absorption capacity than pure zinc-aluminum mixed metal oxides(ZnAl-LDO). The degradation efficiency of catechol reached 94.5% after 5 h irradiation, when loading ratio of AuCu was 5 ∶1 and calcination temperature was 400 ℃. The photodegradation reaction rate constant was 13.4 times that of ZnAlLDO. In addition, The path of AuCu/ZnAl-LDO electron transfer was deduced and a possible photocatalytic degradation mechanism was proposed by density functional theory calculation.更多还原