Huang Lei, Wu Xiangqing, Hijiya Ryota, Teii Kungen
Department of Advanced Energy Science and Engineering, Kyushu University, Kasuga, Fukuoka 816-8580, Japan.
School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, People's Republic of China.
Nanotechnology. 2021 Dec 15;33(10). doi: 10.1088/1361-6528/ac3358.
Seeding of diamond nanoparticles on vertically-aligned multi-layer graphene, the so-called carbon nanowalls (CNWs), is studied by using deionized water, ethylene glycol, ethanol, and formamide as dispersion mediums. Detonation nanodiamond particles show the smallest mean size and size distribution with a high positive zeta potential when dispersed in ethanol. The contact angle of ethanol on CNWs is almost zero degree, confirming highly wetting behaviour. The diamond nanoparticles dispersed in ethanol are distributed the most uniformly with minimal aggregation on CNWs as opposed to those dispersed in other liquids. The resulting diamond nanoparticle-seeded CNWs, followed by short-term growth in microwave plasma chemical vapor deposition, show a marked decrease in field emission turn-on field down to 1.3 Vmtogether with a large increase in current density, compared to bare CNWs without diamond seeding. The results provide a way to control the density, size, and uniformity (spacing) of diamond nanoparticles on CNWs and should be applied to fabricate hybrid materials and devices using nanodiamond and nanocarbons.
以去离子水、乙二醇、乙醇和甲酰胺作为分散介质，研究了在垂直排列的多层石墨烯（即所谓的碳纳米壁，CNWs）上播种金刚石纳米颗粒的情况。爆轰纳米金刚石颗粒在乙醇中分散时，平均尺寸最小，尺寸分布最窄，且具有较高的正zeta电位。乙醇在CNWs上的接触角几乎为零，证实了其高度润湿性。与分散在其他液体中的情况相比，分散在乙醇中的金刚石纳米颗粒在CNWs上分布最均匀，聚集最少。与未播种金刚石的裸CNWs相比，在微波等离子体化学气相沉积中短期生长后，所得的播种金刚石纳米颗粒的CNWs的场发射开启场显著降低至1.3 V/μm，同时电流密度大幅增加。这些结果提供了一种控制CNWs上金刚石纳米颗粒的密度、尺寸和均匀性（间距）的方法，应用于使用纳米金刚石和纳米碳制造混合材料和器件。
