硫化纳米零价铁对五氯苯酚的脱氯及其增强反应

硫化作用可以提高纳米零价铁(nZVI)的催化活性.利用硼氢化物还原法合成了硫化钠米零价铁(S-nZVI)，采用比表面积(BET)、X射线衍射(XRD)、扫描电镜(TEM)、傅立叶变换-红外光谱(FT-IR)和X射线光电子能谱(XPS)等方法对材料进行了物理化学性质的表征，应用高效液相色谱仪和离子色谱仪研究了S-nZVI对五氯苯酚(PCP)的脱氯性能.结果表明:与nZVI相比，S-nZVI在聚集体形态和孔隙率上发生明显改变；不同n(Fe2+)/n(S2-)、溶液pH、S-nZVI的老化以及S-nZVI的重新硫化活化对S-nZVI催化PCP的脱氯均有重要的影响；PCP脱氯效率在n(Fe2+)/n(S2-)=60时达到最大；S-nZVI对PCP的还原转化率随溶液pH(5~8)的升高而显著增加；老化的S-nZVI对PCP的降解性能降低，归因于该老化材料的结构发生了变化；而重新硫化活化产生的FeS层可以减小S-nZVI表面的钝化，从而延长S-nZVI的寿命.文中研究对拓展纳米零价铁的应用和环境污染物治理方面具有一定的参考价值.

The Dechlorination Activity of Sulfide-Modified Nanoscale Zero-Valent Iron for Pentachlorophenol and its Enhanced Reaction

The activity of nanoscale zero-valent iron (nZVI) can be promoted with sulfidation. The physicochemical property of sulfide-modified nanoscale zero-valent iron (S-nZVI) was synthesized with the borohydride reduction method using the specific surface area (BET), X-ray diffraction (XRD), scanning electron microscopy (TEM), infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The dechlorination of pentachlorophenol (PCP) with S-nZVI was studied with high performance liquid chromatography and ion chromatography. As the results showed, compared with nZVI, S-nZVI had a significant change in the particle aggregation degree and porosity; the removal of pentachlorophenol (PCP) was evidently affected by the ratio of n(Fe2+)/n(S2-) and the solution pH as well as the aging and re-vulcanization of S-nZVI material in the reductive dechlorination experiment; the dechlorination efficiency of PCP reached a maximum at n(Fe2+)/n(S2-)=60 and the degradation of PCP with S-nZVI increased significantly with the increase of pH from 5 to 8; the reactivation of aged S-nZVI weakened the PCP degradation due to the structural change of the material; however, the reactivation produced an FeS layer to restrain the surface passivation of nZVI and thus prolonged the life of S-nZVI. This research has implications for expanding the application of nanoscale zero-valent iron and contolling environmental pollutants.