Photo shows China's first lunar sample at the opening ceremony on the Space Day of China on April 24, 2021. Photo: Deng Xiaoci/GT

Chinese researchers have recently discovered a naturally occurring few-layer graphene for the first time in the lunar samples brought back by Chang’e-5 probe, which provides new insights into the moon’s geological activities, evolutionary history, and environmental characteristics, broadening understanding of the complex mineral composition of lunar soil and offering important information and clues for resource utilization on the moon. 

According to the research team from Jilin University, it is estimated that approximately 1.9 percent of the total interstellar carbon exists in the form of graphene, whose morphology and properties are determined by a specific formation process. Therefore, natural graphene can provide important reference and information for the geological evolution of celestial bodies and the in-situ resource utilization on the moon. 

The research team collected Raman spectra, which is used to investigate lunar soils, from areas of the lunar samples with relatively high carbon content, and confirmed that the crystallization quality of the graphite carbon in the lunar samples is relatively high. 

The researchers found that areas of the lunar soil samples containing carbon also contain iron compounds, which the researchers believe is closely related to the formation of graphene. 

Through observation and analysis, the research team confirmed that the graphite form of carbon detected in the lunar soil samples is a type of few-layer graphene. 

The research team confirmed that the formation of few-layer graphene and graphite carbon may originate from mineral catalytic processes induced jointly by the solar wind and early volcanic eruptions on the moon. 

The research conducted by the researchers from Jilin University and the Institute of Metal Research, Chinese Academy of Sciences, and supported by China National Space Administration Lunar Exploration and Space Engineering Center, has recently been published in the National Science Review, a peer-reviewed journal aimed at reporting cutting-edge developments across science and technology in China and around the world. 

A total of 1,731 grams of lunar samples were brought back by Chang’e-5 mission in December 2020. These samples were the first ever obtained from a younger region of the lunar surface which contains volcanic rocks. They are also the first extraterrestrial celestial bodies' samples brought back to Earth by Chinese scientists. 

As of early June this year, a total of 258 lunar samples weighing 77.7 grams have been collected by Chang’e-5 have been distributed to 114 research teams from 40 research institutions. Researchers studying these lunar samples have accomplished a number of milestone achievements with over 70 findings being published in major academic journals both at home and abroad.

Global Times