微波辅助Pb/ZrOx光催化降解水中的对硝基苯酚

采用十六烷基三甲基溴化铵（CTAB）辅助水热法制备了适用于微波辅助光催化体系的高效Pb/ZrOx催化剂，并对其进行了XRD、XPS、BET和SEM等表征，其XPS结果显示在Pb/ZrOx表面，Zr以+2、+3和+4三种价态共存。考察了微波辅助光催化氧化（MW/PC）对硝基苯酚（PNP）过程中，微波辐照功率、催化剂投加量、溶液初始pH和PNP初始浓度对PNP去除效果的影响，得到最优操作条件为，PNP初始pH值为5，催化剂投加量为1.0 g·L-1，微波辐照功率为200 W。此条件下，初始浓度为50 mg·L-1的PNP溶液反应12min后，PNP转化率达95%，TOC去除约70%。并且，Pb/ZrOx能够在重复使用5次的情况下仍保持较好的活性。比较了MW、PC和MW/PC 3种体系，得到MW/PC体系将PNP去除率从单独PC体系的48%提高至95%。微波与紫外光存在良好的协同作用，MW/PC能够快速、高效去除水中PNP，为微波辅助光催化氧化去除污染物提供理论基础。

Microwave-assisted photocatalytic degradation of PNP over Pb/ZrOx

A Pb/ZrOx catalyst was synthesized using a surfactant-assisted hydrothermal method for a microwave-assisted photocatalytic (MW/PC) process. X-ray photoelectron spectroscopy(XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques and Brunauer-Emmett-Teller (BET)surface area analysis method, were adopted to characterize the as-prepared Pb/ZrOx. Three valences (+2, +3, and +4) were found to coexist on the surface of the Pb/ZrOx catalyst based on the XPS results. The effects of microwave power, catalyst dosage, initial pH, and initial p-nitrophenol(PNP) concentration on the degradation of PNP were investigated in detail, and the optimal values of these operating parameters were 200 W, 1.0 g·L-1, about 5, and 50 mg·L-1. Under these optimal conditions, the removal efficiency of PNP reached 95% and TOC removal was 70% after 12 min of reaction. Moreover, the Pb/ZrOx catalyst could be used repeatedly up to 5 cycles without significant loss in its catalytic activity. Compared to the microwave (MW) and photocatalysis (PC) processes, PNP conversion using the MW/PC process was from 48% (PC) to 95% higher. In short, a significant synergistic effect existed between microwaves and photocatalysis. In the MW/PC process, higher degradation efficiency was obtained compared to the traditional PC process.