Di Lijing, Yang Hua, Xian Tao, Liu Xueqin, Chen Xiujuan
State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China.
College of Physics and Electronic Information Engineering, Qinghai Normal University, Xining 810008, China.
Nanomaterials (Basel). 2019 Mar 9;9(3):399. doi: 10.3390/nano9030399.
Z-scheme Ag₂S/BiFeO₃ heterojunction composites were successfully prepared through a precipitation method. The morphology and microstructure characterization demonstrate that Ag₂S nanoparticles (30⁻50 nm) are well-decorated on the surfaces of polyhedral BiFeO₃ particles (500⁻800 nm) to form Ag₂S/BiFeO₃ heterojunctions. The photocatalytic and photo-Fenton catalytic activities of the as-derived Ag₂S/BiFeO₃ heterojunction composites were evaluated by the degradation of methyl orange (MO) under visible-light irradiation. The photocatalytic result indicates that the Ag₂S/BiFeO₃ composites exhibit much improved photocatalytic activities when compared with bare Ag₂S and BiFeO₃. The optimum composite sample was observed to be 15% Ag₂S/BiFeO₃ with an Ag₂S mass fraction of 15%. Furthermore, the addition of H₂O₂ can further enhance the dye degradation efficiency, which is due to the synergistic effects of photo- and Fenton catalysis. The results of photoelectrochemical and photoluminescence measurements suggest a greater separation of the photoexcited electron/hole pairs in the Ag₂S/BiFeO₃ composites. According to the active species trapping experiments, the photocatalytic and photo-Fenton catalytic mechanisms of the Ag₂S/BiFeO₃ composites were proposed and discussed.
通过沉淀法成功制备了Z型Ag₂S/BiFeO₃异质结复合材料。形貌和微观结构表征表明，Ag₂S纳米颗粒（30⁻50 nm）很好地修饰在多面体BiFeO₃颗粒（500⁻800 nm）表面，形成Ag₂S/BiFeO₃异质结。通过可见光照射下甲基橙（MO）的降解来评估所制备的Ag₂S/BiFeO₃异质结复合材料的光催化和光芬顿催化活性。光催化结果表明，与纯Ag₂S和BiFeO₃相比，Ag₂S/BiFeO₃复合材料表现出显著提高的光催化活性。观察到最佳复合样品为Ag₂S质量分数为15%的15%Ag₂S/BiFeO₃。此外，添加H₂O₂可进一步提高染料降解效率，这归因于光催化和芬顿催化的协同效应。光电化学和光致发光测量结果表明，Ag₂S/BiFeO₃复合材料中光激发电子/空穴对的分离程度更大。根据活性物种捕获实验，提出并讨论了Ag₂S/BiFeO₃复合材料的光催化和光芬顿催化机理。
