含Sn水滑石可见光催化降解对氯苯酚的研究

利用水滑石的优良结构特性, 将具有光催化活性的Sn引入水滑石中得到光催化性能较高的含Sn水滑石材料, 通过X射线粉末衍射(XRD)、傅里叶变换红外光谱(FTIR)、紫外可见漫反射图谱 (UV-Vis DRS)和比表面积测量(BET)技术对样品的晶相、分子结构、光学性能和比表面积进行分析表征。以可见光催化降解对氯苯酚(4-CP)为模型, 研究所合成样品的光催化活性。结果表明: 在可见光照射下, 水滑石骨架结构中含Sn的锌锡水滑石表现出更高的光催化活性, 对4-CP的降解率达到92.4%(去除量34.6 mg/g)。并利用气相色谱(GC)和密度泛函理论(DFT)对4-CP的降解中间产物和反应路径进行了推测, 发现光催化过程中的主要中间产物为对苯二酚和4-氯邻苯二酚。

Visible-light Photocatalytic Degradation Effect of Sn-Contained Layered Double Hydroxides on 4-Chlorophenol

With excellent structural characteristics of layered double hydroxides (LDHs), the high photocatalytic properties of Sn-contained LDHs were synthesized by introducing Sn with photocatalytic activity into the brucite type layers. The obtained LDHs solids were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), ultraviolet visible diffuse reflectance spectroscopy (UV-Vis DRS) and Brunauer Emmett Teller (BET) surface area analysis, confirming the crystalline phase, molecular structure, photoresponsive properties and specific surface area. Their photocatalytic activities were evaluated by degradation of 4-chlorophenol (4-CP) under visible light. The results showed that ZnSn-LDHs with skeleton structure containing Sn displayed the best decomposition efficiency of 4-CP (about 92.4% removal efficiency, 34.6 mg/g removal amount) under visible light irradiation. In addition, based on the results from gas chromatography (GC) and periodic density functional theory (DFT) analysis, the photocatalytic degradation mechanism and reaction pathway of 4-CP were investigated in detail. The data presented in this study implied that the main decomposition intermediates of 4-CP were hydrochinone and 4-chloropyrocatechol.