One-step synthesis of mesoporous carbons from mixed resources by microwave-assisted phosphoric acid activation for supercapacitors

Mesoporous carbons (MCs) for supercapacitors were prepared from mixed resources, rice husk and sucrose, by microwave-assisted H3PO4 activation. The surface area of MC6–2–2 made at the H3PO4/rice husk/sucrose mass ratio of 6:2:2 in 20 min heating time at 600 W microwave power reaches 1399 m2 g−1, higher than that of MC8–2–0 made at the H3PO4/rice husk mass ratio of 4. MC6–2–2 retains a high specific capacitance of 150 F g−1 at 0.1 A g−1 after 500 cycles, showing perfect cycle stability. The environment-friendly MCs with low H3PO4 cost exhibit high energy density even at high current density and perfect cycle stability due to the existence of large mesopores.