Synthesis of diamond under amibient pressure using high temperature molten salt electrolysis

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13807
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Inorganic industrial materials
• Research Institution: Kyoto University
• Principal Investigator: Toshiyuki Nohira 京都大学, エネルギー理工学研究所, 教授 (00303876)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: ダイヤモンド / 電解合成 / 常圧 / 溶融塩

Outline of Final Research Achievements

This study was performed to synthesize diamond by electrolysis in a high temperature molten salt under ambient pressure. Molten LiCl-KCl containing K2CO3 (0.2 mol%) and various amout of KOH (0, 2.0, 8.0, 14.0 mol%) was used as an electrolysis bath at 923 K. Samples were prepared by potentiostatic electrolysis at 1.1 V (vs. Li+/Li) using a nickel plate as a substrate. Quantity of electricity was a constant value of 50 C cm-2 for each sample. By micro-Raman spectroscopy, a strong and sharp peak at 1332 cm-1, which is characteristic of diamond, was observed for the sample prepared in the 2.0 mol%-KOH system. Moreover, when the quantity of electricity was reduced to 20 C cm-2, the sharp peaks at 1332 cm-1 were detected at many parts of the substrate. In conclusion, this study confirmed the synthesis of diamond in the liquid phase of molten salt under ambient pressure.

Free Research Field

溶融塩電気化学