Nanomaterials have been widely applied in many fields such as electronics, mechanical devices, drug delivery, catalysts and so forth, due to their unique optical, mechanical, magnetic, electrical, superconducting, and catalytic performances. The direct current (DC) arc plasma is an effective method for preparing nanomaterials with high purity. Specifically, high temperature can be generated by arc discharge between two electrodes, then the gas in the reaction chamber turn into plasma state, and the raw material is evaporated into gaseous atoms. The supersaturated vapor flows to the low temperature part of the reaction chamber, re-nucleates and grows into the desired nanoparticles. The preparation of nanomaterials by DC arc plasma show many advantages, including simple operation, low cost, high synthesis efficiency, high purity of the product, and environmental friendliness. However, in the process of preparing nanomaterials by the arc discharge, changing the relevant experimental parameters will affects the particle size and morphology of the products. Especially, in the preparation of carbon nanomaterials, carbon nanomaterials with diverse morphology, like carbon nanotubes, graphene, and carbon nanohorns can be acquired by varying the experimental conditions. Therefore, it is necessary to find out the optimum synthesis conditions of different nanomaterials from the growth mechanism of nanocrystalline particles and to realize their controllable preparation. Nowadays, the research focus of preparing nanomaterials by arc process has turned from simple preparation methods study into the investigation of the formation mechanism and controllable synthesis parameters, for the sake of realizing the large scale preparation of nanomaterials with controllable particle size and uniform size distribution. In addition, since the arc process is superior to other methods, it is also popular for developing novel nanomaterials by employing arc process. In recent years, fruitful results have been made in the preparation of nanomaterials by the arc discharge. In the field of carbon nanomaterials, not only the preparation of fullerenes and carbon nanotubes, but also the synthesis of high quality monolayer graphene and carbon nanohorns have been realized successfully. In terms of metal nanomaterials, high quality silver and nickel nanopowders have been obtained. In addition, nanomaterials of refractory metals are difficult to prepare by other methods because of their high melting point. While the temperature of arc zone can reach 104 K, hence the nanomaterials of various refractory metals such as Mo, Cr, V, and W can be achieved by this method. Considering the ceramic nanomaterials, high performance ceramic nanomaterials like SiC and TiC have been successfully prepared. Besides, the formation and growth mechanism of nanoparticles should be explored deeply in order to realized the controllable preparation of nanomaterials by arc discharge. Recently, researchers use numerical simulations and other auxiliary methods to simulate the arc process, and temperature, pressure, and velocity distribution of the arc zone can be obtained. The simulated experimental results play a crucial role in explaining the growth mechanism of nanomaterials. This review introduces the research progress of preparing carbon, metallic, and ceramic nanomaterials by the DC arc plasma. The formation mechanism of nanoparticles is analyzed in depth. The problems existing in the preparation of nanomaterials by arc plasma method are described, and corresponding solutions are put forward. Finally, the prospect of large scale, low cost, controllable preparation of nanomaterials by the DC arc discharge is illustrated. © 2019, Materials Review Magazine. All right reserved.
