Synthesis of nanoscale zero-valent iron supported on exfoliated graphite for removal of nitrate  

作　　者：张环 金朝晖 韩璐 秦承华 

机构地区：[1]Department of Environmental Science and Engineering,Nankai University,Tianjin 300071,China [2]Department of Material Science and Chemical Engineering,Tianjin Polytechnic University,Tianjin 300160,China

出　　处：《中国有色金属学会会刊：英文版》2006年第B01期345-349,共5页Transactions of Nonferrous Metals Society of China

基　　金：Project(20477019) supported by the National Natural Science Foundation of China

摘　　要：Nano ZVI particles supported on micro-scale exfoliated graphite were prepared by using KBH4 as reducing agent in the H2O/ethanol system. The supported ZVI materials generally have higher activity and greater flexibility for environmental remediation applications. The exfoliated graphite as the support was treated beforehand to hydrophilic material. Nano iron particles are deposited onto the rough graphite surface while those were formed by borohydride reduction. The possible nitrate reduction pathways were proposed. The TEM image shows that iron particles are highly dispersed on the surface of graphite and several of iron particles are imbedded in the pit of support surface. In this synthesis, iron particles have a nearly spherical shape with a grain size of 50?100 nm. The surface areas of materials with different iron loadings of 3.5%, 7.0%, 10.0%, 15.0% and 20.0%(mass fraction) are 2.89, 9.55, 8.45, 23.8 and 6.18 m2·g?1 by BET surface analyzer. The chemical reduction of nitrate by supported nano ZVI in aqueous solution were tested in series batch experiments. Experiment results suggest that NO3? can be more rapidly reduced to NH4+ at neutral pH and anaerobic conditions by supported nano ZVI than unsupported nano ZVI or ZVI scraps. The 15% nano Fe/graphite shows the best reduction efficiency contrasted with other Fe loading particles.Nano ZVI particles supported on micro-scale exfoliated graphite were prepared by using KBH4 as reducing agent in the H2O/ethanol system. The supported ZVI materials generally have higher activity and greater flexibility for environmental remediation applications. The exfoliated graphite as the support was treated beforehand to hydrophilic material. Nano iron particles are deposited onto the rough graphite surface while those were formed by borohydride reduction. The possible nitrate reduction pathways were proposed. The TEM image shows that iron particles are highly dispersed on the surface of graphite and several of iron particles are imbedded in the pit of support surface. In this synthesis, iron particles have a nearly spherical shape with a grain size of 50-100 nm. The surface areas of materials with different iron loadings of 3,5%, 7.0%, 10.0%, 15.0% and 20.0%（mass fraction） are 2.89, 9.55, 8.45, 23.8 and 6.18 m2·g^-1 by BET surface analyzer. The chemical reduction of nitrate by supported nano ZVI in aqueous solution were tested in series batch experiments. Experiment results suggest that NO3^- can be more rapidly reduced to NH4^＋ at neutral pH and anaerobic conditions by supported nano ZVI than unsupported nano ZVI or ZVI scraps, The 15% nano Fe/graphite shows the best reduction efficiency contrasted with other Fe loading particles.

关 键 词：纳米级0价铁粒子 合成 片状剥落石墨 载体 硝酸盐脱除 

分 类 号：TB383.1[一般工业技术—材料科学与工程]