如何构筑高性能的电催化剂是提高卤代有机污染物电催化还原去除的关键.本研究通过化学共还原的方法制备出钯铜(PdCu)纳米合金催化剂,通过扫描电子显微镜(SEM)、高分辨率透射电子显微镜(HRTEM)、能量色散X射线光谱(EDX)、X射线衍射(XRD)、X射线光电子能谱(XPS)、线性扫描伏安法(LSV)和电化学阻抗谱(EIS)等方法对其微观结构和电化学性能进行表征,并探究PdCu纳米合金催化剂对抗生素氟苯尼考(Florfenicol,FLO)电催化还原的降解机理.实验结果表明,所制备的PdCu纳米合金催化剂中Pd、Cu纳米颗粒分布均匀,具有优异的电化学还原性能和动力学性能以及快速的电子转移速率.PdCu纳米合金催化剂在-1.3 V vs.Hg/Hg_(2)SO_(4)下,120 min内对FLO的去除率高达97.5%,远高于纯Pd(82.9%)、纯Cu(67.4%)金属纳米颗粒催化剂的去除率,中性pH更有利于FLO的降解.叔丁醇淬灭实验表明,吸附态原子氢在电催化还原去除FLO过程中起重要作用.使用液质联用仪(LC-MS/MS)对FLO降解后的产物进行半定量分析表明,在PdCu纳米合金催化剂上FLO的电催化还原是一个逐步脱卤的过程,在实现完全脱氯后再进行脱氟.本研究为电催化高效还原卤代有机污染物提供了一种具有应用潜力的催化剂方案.
We provide a new way to prepare ZnO nanorods pattern from the solution composed of hexamethylenetetramine （HMT） and Zn（NO3）2. The substrate is ITO substrate covered by well ordered Au islands. Since Au and the underneath ITO substrate have two different nucleation rates in the initial stage of heterogeneous nucleation process, the subsequent ZnO growth on the quick nucleating area takes place under diffusion control and is able to confine the synthesis of ZnO nanorods to specific locations. The concentrations of zinc nitrate and HMT are well adjusted to show the possibility of the new route for the patterning of the ZnO nanorods. Furthermore, the nanorods pattern was characterized by X-ray diffraction and photoluminescence and the performance of field emission property from ZnO nanorod patterns was investigated. The ZnO nanorods pattern with a good alignment also shows a good field enhancement behavior with a high value of the field enhancement factor.
