Carbonization under pressure

Carbonization under pressure was reviewed by being classified into three routes: carbonization of the precursors under pressure of their decomposition gases, carbonization under hydrothermal conditions, and reduction of pressu~rized CO₂. Carbon materials with different structures and nanotextures were formed with relatively high yield under pressure, but obtained as a mixture in most cases. In this review, the formation conditions of carbon spheres in pure and an individually separated state are discussed by focusing on the temperature-pressure conditions and the chemical composition of the precursors used.