Hard template–salt template double template preparation of heteroatom-doped hierarchical porous carbon and its electrochemical properties†

Abstract

Heteroatom-doped hierarchical porous carbon (AF-MMTC) was prepared with hard template and salt template dual templating agents, and the effects of salt template additions on its micro-morphology, pore structure, specific surface area and electrochemical properties were investigated. The salt template not only acts as a template, but also plays the role of a pore-making agent. AF-MMTC5 has a high specific surface area of 1772 m² g⁻¹, a 41% microporous content and 1.8 at% nitrogen content. The electrochemical test results show that the specific capacitance of AF-MMTC5 is 231.9 F g⁻¹ (0.5 A g⁻¹) in the three-electrode system, and the capacity retention can reach 98.5% after 5000 cycles; in the two-electrode system, the specific capacitance of AF-MMTC5 can reach 216.3 F g⁻¹ when the current density is 0.5 A g⁻¹, and the specific capacitance can still reach 172.2 F g⁻¹ when the current density is increased to 20 A g⁻¹. AF-MMTC5 represents the highest energy density of 4.81 W h kg⁻¹ at the power density of 50 W kg⁻¹. And the capacity retention rates of AF-MMTC5 is 85.1%. The good electrochemical properties of AF-MMTC5 indicate that it has great potential for application in supercapacitor electrode materials. In addition, the results provide useful information for the preparation of hierarchical porous carbon with high specific surface area.