▎ 摘　　要

Diamond aerogel, a special kind of carbon aerogel made by sp(3) carbon atoms, has been attracting intensive research interest due to its potential applications since it is first synthesized by the conversion of amorphous carbon. Despite of many expectations in diamond aerogel, the study on its synthesis is still not adequate compared with other carbon aerogel. Here we report the synthesis of diamond aerogel by laser heating graphene aerogel (GA) under high pressure in a diamond anvil cell. The results suggest that the density and microstructure of GA, as well as the heating duration obviously affect the diamond aerogel growth. When heating GA with lower laser power, we also observe a transparent carbon phase in experiment, which transforms into graphite and amorphous carbon upon decompression. These results present new insights into our understanding on the transformation from ultralow density carbon to sp(3) carbon under high pressure and high temperature. It is possible to tune the microstructures of diamond aerogel by controlling the synthesis of GA precursors.