包覆型纳米零价铁的制备及其对染料溶液的脱色性能

采用一步法合成了SiO_2包覆型纳米零价铁(SiO_2-NZVI),并采用TEM,XRD,FTIR及EDS方法对其进行了表征,考察了SiO_2-NZVI对偶氮、蒽醌、三苯甲烷3种不同类型的染料溶液的脱色能力。表征结果表明:SiO_2-NZVI平均粒径为15~22 nm,SiO_2薄膜厚度均一,约为10 nm;SiO_2-NZVI中所含元素主要为Fe和Si,质量比为90.6∶9.4。实验结果表明:SiO_2-NZVI对3种染料溶液均具有脱色能力,在染料溶液质量浓度为100 mg/L、SiO_2-NZVI加入量为2 g/L、反应时间为35 min的条件下,对甲基橙、孔雀石绿、洋红溶液的脱色率分别为86.04%,97.50%,82.13%;SiO_2-NZVI相对于NZVI有更强的抗氧化能力,且酸性环境有利于SiO_2-NZVI对染料溶液的脱色。

Preparation of SiO2-coated NZVI and its decolorization ability to dye solution

SiO₂-coated nano-scale zero-valent iron（SiO₂-NZVI）was synthesized by one-step method and characterized by TEM,XRD,FTIR and EDS. The decolorization abilities of SiO₂-NZVI to 3 different sorts of dye solutions including azo dye,anthraquinone dye and triphenylmethane dye were investigated. The characterization results show that：The average grain diameter of SiO₂-NZVI is 15-22 nm,and the thickness of the uniform SiO₂ film is approximately 10 nm;The main elements in SiO₂-coated NZVI are Fe and Si,with the mass ratio of 90.6∶9.4. The experimental results show that：SiO₂-NZVI has decolorization ability to each of the 3 dye solution,and under the conditions of mass concentration of dye solution 100 mg/L,SiO₂-NZVI dosage 2 g/L and reaction time 35 min,the decolorizaition rate of the dye solution containing methyl orange,malachite green and magenta is 86.04%,97.50%,82.13% respectively;SiO₂-NZVI is more resistant to oxidation than NZVI and acidic environment is beneficial for decolorizaition.