Novel synthesis method of diamond from carbon dioxide and water under ambient pressure by using molten salt electrolysis

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K19130
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 36:Inorganic materials chemistry, energy-related chemistry, and related fields
• Research Institution: Kyoto University
• Principal Investigator: Nohira Toshiyuki 京都大学, エネルギー理工学研究所, 教授 (00303876)
• Project Period (FY): 2018-06-29 – 2020-03-31
• Keywords: ダイヤモンド / 電解合成 / 溶融塩

Outline of Final Research Achievements

Generally, diamond is synthesized by high temperature and high pressure (HPHT) method or chemical vapor deposition (CVD) method. So far, there are no reports concerning the diamond synthesis from liquid phase under ambient pressure. In the present study, the author investigated the electrolytic synthesis of diamond from molten salt (liquid phase) under ambient pressure. As the result, the synthesis of diamond was confirmed by micro Raman spectroscopy. The author also obtained useful information concerning the optimal electrolysis condition for diamond synthesis. Finally, the author confirmed the possibility of using carbon dioxide and water as the raw materials for diamond.

Free Research Field

電気化学

Academic Significance and Societal Importance of the Research Achievements

これまで、ダイヤモンドは高圧高温合成法や気相合成法で合成されており、常圧液体からの合成例は知られていなかった。本研究では、液相である溶融塩を用いて常圧下でのダイヤモンド合成を達成しており、学術的に価値が高い。さらに、原料として二酸化炭素と水を用いる可能性も確認した。これは、新たな二酸化炭素固定法としての展開が期待できるため、社会的意義も大きい。