A cost-effective way to maintain metal-doped carbon xerogels and their applications on electric double-layer capacitors

► Metal nitrates' double roles as catalyst of sol-gel reaction and graphitization to simplify the process. ► 2 dimensional channel-like active graphitic structure helps to show a better capacitive behavior. ► Co doped carbon xerogel exhibited the largest specific capacitance of 84 F g−1 and good cycling stability.