Facile one-pot synthesis of highly porous carbon foams for high-performance supercapacitors using template-free direct pyrolysis

Foam-like porous carbons with specific surface area (SSA) up to 2340 m²/g were synthesized using direct pyrolysis of sugar and zinc nitrate mixtures without any hard templates. The role of the ZnO nanoparticles formed from the decomposition of zinc nitrate, and the effects of high-temperature annealing on the formation of the high-SSA carbon foams were systematically studied. Due to the facile and quick reaction conditions, these carbon foams could be easily synthesized on a large scale. When used as supercapacitor electrode materials, a specific capacitance up to 280 F/g was achieved at current density of 0.1 A/g and remained as high as 207 F/g, even at a high current density of 10 A/g.