In_2S_3-Ag/TiO_2三元纳米体系光催化降解2,4-D的实验研究

采用两步沉积法首次合成出新三元纳米材料-In2S3-Ag/TiO2纳米管阵列,并用电子扫描显微镜(SEM)、光致发光光谱仪(PL)等仪器对该三元催化剂进行形貌、元素、晶体结构的表征与光电性能的测试,并将该三元催化体系应用于2,4-二氯苯氧乙酸(2,4-D)的光降解实验.结果表明,In2S3-Ag/TiO2三元纳米材料所特有的两步光激发体系使它的催化降解能力显著提高,在溶液pH为4.23时,140min内可实现对2,4-D 100%的去除;强酸和强碱的环境都不利于三元催化剂In2S3-Ag/TiO2对2,4-D的催化降解.最后对三元催化剂的光催化降解机理进行了探讨.

The Investigation of Photodegradation of 2,4-D by the Three-component System In2S3-Ag/TiO2 Nanotube Arrays

A new kind of three-component nanomaterials-In2S3-Ag/TiO2 nanotube arrays was first synthesized in two-step deposition method. In this study, the morphology, elements, crystal structure and photoelectric property testing of the three-component photocatalyst were characterized by scanning electron microscope (SEM) and fluorescence photoluminescence spectra (PL), etc. The three-component photocatalyst was applied to the photodegradation 2,4-dichlorophenoxyacetic acetic acid (2,4-D). The photocatalytic degradation experiment results of 2,4-D have shown that its 100% removal rate can be achieved within 140 minutes. The unique two-step excitation process in the three-component In2S3-Ag/TiO2NTs system leads to the significant improvement of photocatalytic ability. The experiments indicate that different values of pH and the concentration of 2,4-D have significant effect on degradation. The preliminary results show that the photocatalytic reactions are optimized at pH 4.23, higher or lower pH levels will reduce the removal rate due to the phase change of 2,4-D molecules. The photocatalytic degradation mechanism was also analyzed with equations and model diagrams.