Sythesis And Properties Of Nickel-Based Nanocomposites

In this paper,nickel based composite nano materials were prepared by chemical reduction and replacement reaction.The nano materials prepared by chemical reduction were studied by addition ligands?ethylenediamine,sodium glycinate,sodium citrate?and H₂O₂.All the prepared materials were characterized by XRD,TEM,BET and H₂-TPD,then the activity of catalysts were evaluated.The experimental results are as follows:Ni-B amorphous nanoparticles prepared by ligand regulation showed a high catalytic hydrogen production performance,because the chemical reaction speed could be effectively controlled with ligand regulation,then excessive generation and aggregation of particles could be prevented,the size of the spherical particles was reduced,the surface area,the number of active center and dispersion of the catalysts were increased,then the rate of hydrogen production was accelerated.It was also found that H₂O₂ played a key role in the morphology regulation of Ni-B nanoparticles.The Ni-B amorphous nanoparticles exhibited the best electrocatalytic properties and the surface area was the biggest when the molar ratio of Ni to ethylenediamine was 1:3,the molar ratio of Ni to H₂O₂ was 1:1.The regulation ability of sodium glycine and H₂O₂ was weaker than ethylenediamine and H₂O₂.Ni-Co-B amorphous alloy nanoparticles prepared by replacement mothod had better dispersion,larger specific surface area,larger number of active centers,and higher catalytic hydrogen production rate than Co reduction method.The optimal replacement time was 1 h.With the addition of ligand,the performance of the nanoparticles was better,Co was almost completely replaced by Ni.The electrocatalytic performance of Ni-Co-B/GC electrode for ethanol oxidation was studied by cyclic voltammetry.The results indicated that the catalysts prepared by replacement method with 1 h showed the highest catalytic oxidation activity with addition of ligand regulation.