Nanoscale bimetallic Ni/Fe particles were synthesized from the reaction of sodium borohydride （NaBH4） with reduction of Ni^2＋ and Fe^2＋ in aqueous solution. The obtained Ni/Fe particles were characterized by TEM ...Nanoscale bimetallic Ni/Fe particles were synthesized from the reaction of sodium borohydride （NaBH4） with reduction of Ni^2＋ and Fe^2＋ in aqueous solution. The obtained Ni/Fe particles were characterized by TEM （transmission electron microscope）, XRD （X-ray diffractometer）, and N2-BET. The dechlorination activity of the Ni/Fe was investigated using p-chlorophenol （p-CP） as a probe agent. Results demonstrated that the nanoscale Ni/Fe could effectively dechlorinate p-CP at relatively low metal to solution ratio of 0.4 g/L （Ni 5 wt%）. The target with initial concentration ofp-CP 0.625 mmol/L was dechlorinted completely in 60 rain under ambient temperature and pressure. Factors affecting dechlorination efficiency, including reaction temperature, pH, Ni loading percentage over Fe, and metal to solution ratio, were investigated. The possible mechanism of dechlorination ofp-CP was proposed and discussed. The pseudo-first- order reaction took place on the surface of the Ni/Fe bimetallic particles, and the activation energy of the dechlorination reaction was determined to be 21.2 kJ/mol at the temperature rang of 287-313 K.展开更多
Microstructure of γ (Fe,Ni) alloy particles has been investigated by means of X ray diffraction and high resolution electron microscopy. The result shows that most of particles are of γ (Fe,Ni) alloy and the part...Microstructure of γ (Fe,Ni) alloy particles has been investigated by means of X ray diffraction and high resolution electron microscopy. The result shows that most of particles are of γ (Fe,Ni) alloy and the particle size is around 10 nm. EDS analysis indicates that Fe or Ni content of individual particle may be different from others and Fe or Ni content distribution is given in the paper as well. The nanometer particles have excellent optical and microwave properties in electromagnetic applications.展开更多
Chlorinated phenols are a kind of environmental priority pollutants that attract much attention. The effect of Ni on the removal of pentachlorophenol （PCP） with Fe nanoparticles was investigated in this study. Fe na...Chlorinated phenols are a kind of environmental priority pollutants that attract much attention. The effect of Ni on the removal of pentachlorophenol （PCP） with Fe nanoparticles was investigated in this study. Fe nanoparticles and Ni submicron particles were synthesized using chemical reduction method and wet chemical techniques, respectively. And the concentrations of PCP and chloride ion in solutions were measured with and without Ni present. The results showed that the dechlorination of PCP was promoted in the presence of Ni particles, and the dechlorination efficiency was reduced along with the increase of Ni size. When the diameter of Ni particle was smaller than 300 nm, the removal efficiency of PCP was obviously increased in the initial 4 h, and then became the similar to that of the system with Fe only. When the diameter of Ni particle was between 400 nm and 1 μm, the removal efficiency of PCP was increased in the initial 1 h. Then the removal of PCP was inhibited, and the inhibition was increased with the increase of Ni size. Later, the removal efficiency was the similar in various systems.展开更多
基金Project supported by the National Basic Research Program (973) of China(No. 2003CB415006)the National Natural Science Foundation of China (No. 20337020)
文摘Nanoscale bimetallic Ni/Fe particles were synthesized from the reaction of sodium borohydride （NaBH4） with reduction of Ni^2＋ and Fe^2＋ in aqueous solution. The obtained Ni/Fe particles were characterized by TEM （transmission electron microscope）, XRD （X-ray diffractometer）, and N2-BET. The dechlorination activity of the Ni/Fe was investigated using p-chlorophenol （p-CP） as a probe agent. Results demonstrated that the nanoscale Ni/Fe could effectively dechlorinate p-CP at relatively low metal to solution ratio of 0.4 g/L （Ni 5 wt%）. The target with initial concentration ofp-CP 0.625 mmol/L was dechlorinted completely in 60 rain under ambient temperature and pressure. Factors affecting dechlorination efficiency, including reaction temperature, pH, Ni loading percentage over Fe, and metal to solution ratio, were investigated. The possible mechanism of dechlorination ofp-CP was proposed and discussed. The pseudo-first- order reaction took place on the surface of the Ni/Fe bimetallic particles, and the activation energy of the dechlorination reaction was determined to be 21.2 kJ/mol at the temperature rang of 287-313 K.
文摘Microstructure of γ (Fe,Ni) alloy particles has been investigated by means of X ray diffraction and high resolution electron microscopy. The result shows that most of particles are of γ (Fe,Ni) alloy and the particle size is around 10 nm. EDS analysis indicates that Fe or Ni content of individual particle may be different from others and Fe or Ni content distribution is given in the paper as well. The nanometer particles have excellent optical and microwave properties in electromagnetic applications.
基金Supported by the National Natural Science Foundation(51108454)
文摘Chlorinated phenols are a kind of environmental priority pollutants that attract much attention. The effect of Ni on the removal of pentachlorophenol （PCP） with Fe nanoparticles was investigated in this study. Fe nanoparticles and Ni submicron particles were synthesized using chemical reduction method and wet chemical techniques, respectively. And the concentrations of PCP and chloride ion in solutions were measured with and without Ni present. The results showed that the dechlorination of PCP was promoted in the presence of Ni particles, and the dechlorination efficiency was reduced along with the increase of Ni size. When the diameter of Ni particle was smaller than 300 nm, the removal efficiency of PCP was obviously increased in the initial 4 h, and then became the similar to that of the system with Fe only. When the diameter of Ni particle was between 400 nm and 1 μm, the removal efficiency of PCP was increased in the initial 1 h. Then the removal of PCP was inhibited, and the inhibition was increased with the increase of Ni size. Later, the removal efficiency was the similar in various systems.
