CMC稳定的Ni/Fe双金属催化体系的制备及对PCB77原位脱氯降解

摘要

The CMC-Ni-Fe bimetallic nanoparticles were successful synthesized with the monodispersed car-boxymethyl cellulose ( CMC) as a stabilizer. The various reaction parameters were optimized. Nanoparticles, prepared with m( CMC)/m( Fe) =5 and m(Ni)/m(Fe) =0.03 at 25 t , showed the best degradation effect of PCB77. Near 94% of reduction efficiency was achieved by CMC-Ni/Fe bimetallic nanoparticles for 48 h treatment, while only about 71% PCB77 was degraded by Ni/Fe bimetallic nanoparticles. The results of XRD showed that the CMC-Ni/Fe bimetallic nanoparticles exhibited the characteristic peaks of elemental iron and the characteristic peaks of iron oxides were not detected. It was indicated that the elemental iron of CMC-Ni/Fe bimetallic nanoparticles was not oxidized in preparation process. The results of particle size analysis were demonstrated that the average diameter of CMC-stabilized Ni-Fe bimetallic nanoparticles was about 23. 94 nm, smaller than the particle size of Ni/Fe bimetallic nanoparticles (100 nm).%以羧甲基纤维素钠(CMC)作为稳定剂,优化了制备条件,在反应温度25℃,m(CMC)/m(Fe)=5以及m(Ni)/m(Fe) =0.03的条件下成功制备了CMC-Ni/Fe纳米双金属颗粒.用制得的CMC-Ni/Fe纳米双金属颗粒于30℃下降解5 mg/L的PCB77溶液48 h,当双金属颗粒用量为3 g/L时,有高达94％的PCB77被降解,而没有加入CMC的Ni/Fe双金属体系只有71％的PCB77被降解.CMC-Ni/Fe纳米双金属颗粒经XRD检测,表现出明显的单质铁特征峰,且无铁氧化物特征峰,表明制备所得的纳米颗粒中的铁单质没有被氧化.经粒度分析仪的检测,CMC-Ni-Fe双金属纳米颗粒平均粒径在23.94 nm,明显小于没有加CMC的Ni/Fe双金属颗粒粒径(100 nm).