Su Fengmei, Qiu Xuechao, Liang Feng, Tanaka Manabu, Qu Tao, Yao Yaochun, Ma Wenhui, Yang Bin, Dai Yongnian, Hayashi Katsuro, Watanabe Takayuki
Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China.
State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization, Kunming University of Science and Technology, Kunming 650093, China.
Nanomaterials (Basel). 2018 Sep 1;8(9):684. doi: 10.3390/nano8090684.
Nickel nanoparticles were prepared by the arc discharge method. Argon and argon/hydrogen mixtures were used as plasma gas; the evaporation of anode material chiefly resulted in the formation of different arc-anode attachments at different hydrogen concentrations. The concentration of hydrogen was fixed at 0, 30, and 50 vol% in argon arc, corresponding to diffuse, multiple, and constricted arc-anode attachments, respectively, which were observed by using a high-speed camera. The images of the cathode and anode jets were observed with a suitable band-pass filter. The relationship between the area change of the cathode/anode jet and the synchronous voltage/current waveform was studied. By investigating diverse arc-anode attachments, the effect of hydrogen concentration on the features of nickel nanoparticles were investigated, finding that 50 vol% H₂ concentration has high productivity, fine crystallinity, and appropriate size distribution. The synthesized nickel nanoparticles were then used as catalysts in a hybrid sodium⁻air battery. Compared with commercial a silver nanoparticle catalyst and carbon black, nickel nanoparticles have better electrocatalytic performance. The promising electrocatalytic activity of nickel nanoparticles can be ascribed to their good crystallinity, effective activation sites, and Ni/NiO composite structures. Nickel nanoparticles prepared by the direct current (DC) arc discharge method have the potential to be applied as catalysts on a large scale.
通过电弧放电法制备了镍纳米颗粒。氩气和氩气/氢气混合物用作等离子体气体；阳极材料的蒸发主要导致在不同氢气浓度下形成不同的电弧-阳极附着形式。在氩弧中，氢气浓度分别固定为0、30和50体积%，分别对应于扩散、多重和收缩的电弧-阳极附着形式，这些通过高速摄像机进行观察。使用合适的带通滤波器观察阴极和阳极射流的图像。研究了阴极/阳极射流面积变化与同步电压/电流波形之间的关系。通过研究不同的电弧-阳极附着形式，研究了氢气浓度对镍纳米颗粒特性的影响，发现50体积%的H₂浓度具有高生产率、良好的结晶度和合适的尺寸分布。然后将合成的镍纳米颗粒用作混合钠-空气电池中的催化剂。与商业银纳米颗粒催化剂和炭黑相比，镍纳米颗粒具有更好的电催化性能。镍纳米颗粒有前景的电催化活性可归因于其良好的结晶度、有效的活性位点和Ni/NiO复合结构。通过直流（DC）电弧放电法制备的镍纳米颗粒有大规模应用作催化剂的潜力。
