Solution Plasma Synthesis Process of Carbon Nano Particles in Organic Solutions
O. L. Li1, J. Kang2, K. Urashima2, and N. Saito1, 2, 3
1Green Mobility Collaborative Research Center, Nagoya University, Japan
2Graduate School of Engineering, Nagoya University, Japan
3Ecotopia Science Research Institute, Nagoya University, Japan
Abstract- In this study, solution plasma process (SPP) was applied to synthesis carbon nanoparticles in organic solution. In the SPP process, carbon nanoparticles were formed by carbon atoms supplied by two different groups of organic solutions, sugar and aromatic hydrocarbon solutions. Glucose, sucrose and fructose were used as sugar solution, whereas benzene and toluene were applied for the aromatic hydrocarbon solutions. Within the same group of solution, the carbon structure and size distribution were found to be similar. On average, 100 ml sugar solution produced 15 mg of carbon by weight. The particles included hemisphere and sphere in shape, with a size distribution between 100 - 600 nm. For aromatic hydrocarbon solutions, 930 and 1000 mg of carbon could be generated, respectively, from 100 ml of pure toluene and benzene. The particles were spherical shape with a size distribution of 20 - 30 nm. Fundamental characteristics of plasma discharge including voltage and current waveforms, as well as active species generated were compared. The discharge in sugar solution occurred in three different phases: pre-discharge, the initiation and the formation of discharge, whereas the discharge in benzene happened in two main steps: pre-discharging and the formation of discharge. From the optical emission spectrum, the major active species obtained from sugar solution were Hα (656 nm), followed by atomic O (777 nm), Hβ (486 nm) and relatively low intensity of atomic C (247 nm). For benzene and toluene solutions, the majority active species were observed to be C2 (513 nm) and CH (431 nm) and followed by Hα (656 nm). The results indicated pure benzene might be suitable solution applied for the synthesis of carbon nanoparticles in solution plasma process.
Keywords- Solution plasma, carbon nano particles, sugar, aromatic hydrocarbon, benzene