Synthesis of microporous Ni/NiO nanoparticles with enhanced microwave absorption properties
Synthesis of microporous Ni/NiO nanoparticles with enhanced microwave absorption properties
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DOI：
10.1016/j.jallcom.2016.01.175
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发表时间：
2016-05
影响因子：
6.2
通讯作者：
Tong Liu;Yu Pang;Xiubo Xie;W. Qi;Ying Wu;Satoru Kobayashi;Jie Zheng;Xingguo Li
中科院分区：
文献类型：
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作者：
Tong Liu;Yu Pang;Xiubo Xie;W. Qi;Ying Wu;Satoru Kobayashi;Jie Zheng;Xingguo Li
微孔金属材料由于其高化学活性和孔径难以控制而具有许多潜在的应用，其制备具有挑战性。通过调整反应条件和Ni-Al纳米粒子前驱体的组成，采用化学脱合金法成功制备了22 nm的微孔Ni纳米粒子。在钝化过程中，由于表面氧化的结果，生成了被NiO壳覆盖的微孔Ni NPs。微孔直径为0.6 - 1.2 nm，比表面积为68.9 m2/g。由于脱合金过程中Al原子的消除，微孔Ni NPs的晶粒尺寸急剧减小至2-5 nm。这种特定的结构为微孔Ni/NiO NP提供了小的微波反射系数（RC）和宽的吸收带宽（RC ≤ −10 dB），分别为−49.1 dB和5.8 GHz，远优于无孔的-24.1 dB和3.7 GHz。从纳米结构、核/壳结构和纳米结构效应等方面对复合材料的吸波性能进行了解释。
The fabrication of microporous metal materials with many potential applications is challenging due to their high chemical activities and the difficulty in controlling the pore size. By adjusting the reaction condition and the composition of the Ni–Al nanoparticle precursor, we have successfully produced the microporous Ni nanoparticles (NPs) of 22 nm by chemical dealloying method. During the passivation process, the microporous Ni NPs covered with NiO shell are generated as the result of surface oxidation. The micropores range from 0.6 to 1.2 nm in diameter with a large surface area of 68.9 m2/g. Due to the elimination of Al atoms during dealloying process, the crystalline size of the microporous Ni NPs is sharply decreased to 2–5 nm. The specific architecture offers the microporous Ni/NiO NPs a small microwave reflection coefficient (RC) and a wide absorption bandwidth (RC ≤ −10 dB) of −49.1 dB and 5.8 GHz, much better than the nonporous counterpart of −24.1 dB and 3.7 GHz. The enhanced microwave absorption performance has been interpreted in terms of the micropore structure, core/shell structure and nanostructure effects.