ABSTRACT

A simple and low-cost route to fabricate sepiolite-supported bimetallic Fe/Ni (Sep-Fe/Ni) nanoparticles was obtained by synchronous liquid phase reduction method. The as prepared composite was used to remove triclosan (TCS) from aqueous solutions. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller (BET) analysis were used for characterization of the materials. As the supporting material, Sep dispersed Fe/Ni nanoparticles on its surface effectively and reduced the agglomeration phenomenon, providing more reactive sites. Sep-Fe/Ni had a large surface area of 90.5 m²/g, which was considerably higher than that of Fe/Ni (9.2 m²/g). Sep-Fe/Ni exhibited an enhanced TCS removal efficiency, as compared to the Fe/Ni and Sep materials. Operation factors, including the solution pH, initial TCS concentration, and material dosage, were investigated and found to be influential for TCS removal. The kinetic analysis indicated that the depletion of TCS in aqueous solutions conformed to the pseudo-first-order kinetic model under optimized conditions. The transformation pathway of TCS was studied in detail, revealing that the dechlorination of TCS by Sep-Fe/Ni is a stepwise reaction, namely from TCS to di-chlorinated intermediates, with the newly formed intermediate products also degrading into mono-chlorinated products by further reductive dechlorination. This study demonstrated that Sep-Fe/Ni is a promising reductant for TCS removal in water.

摘要

通过同步液相还原法获得了一种制备海泡石负载双金属铁/镍（Sep-Fe/Ni）纳米粒子的简单且低成本的途径。所制备的复合材料用于从水溶液中去除三氯生 (TCS)。X 射线衍射、扫描电子显微镜、透射电子显微镜和 Brunauer-Emmett-Teller (BET) 分析用于表征材料。作为支撑材料，Sep 有效地将 Fe/Ni 纳米粒子分散在其表面，减少了团聚现象，提供了更多的反应位点。^{Sep-Fe/Ni 具有 90.5 m 2} /g的大表面积，大大高于 Fe/Ni（9.2 m ²/G）。与 Fe/Ni 和 Sep 材料相比，Sep-Fe/Ni 表现出增强的 TCS 去除效率。研究了操作因素，包括溶液 pH 值、初始 TCS 浓度和材料用量，发现它们对 TCS 去除有影响。动力学分析表明，在优化条件下，TCS在水溶液中的消耗符合准一级动力学模型。详细研究了TCS的转化途径，揭示了Sep-Fe/Ni对TCS的脱氯是一个逐步反应，即从TCS到二氯化中间体，新形成的中间产物也通过降解为一氯化产物。进一步还原脱氯。该研究表明，Sep-Fe/Ni 是一种很有前途的还原剂，可用于去除水中的 TCS。