Research Progress on the Formation and Regulation Mechanisms of sp³ Amorphous Carbon under High Pressure

Since the successful synthesis of bulk sp³ amorphous carbon in 2021, this material has attracted considerable attention owing to its ultrahigh hardness, mechanical isotropy, potential for shaping and machining, and distinctive electronic structure. These features make it a promising candidate for applications in ultra-precision machining and optoelectronic detection. Recent studies have mainly focused on the formation mechanism, thermodynamic stability, structural and property regulation, and synthesis process optimization of sp³ amorphous carbon materials derived from fullerenes under high-pressure and high-temperature conditions. These studies have not only deepened the understanding of the formation mechanism of sp³ amorphous carbon, but also promoted the further development of its functional applications. This review systematically summarizes the relevant research progress and discusses future key directions, including the large-size and high-quality synthesis, precision shaping, and functional application expansion of sp³ amorphous carbon.