A new nanoarchitecture approach based on metal-organic frameworks (MOF) is reported that can achieve high electrochemical energy storage via utilizing both electric double-layer supercapacitive and pseudocapacitive properties within a single nanoporous composite particle. Herein, a predesigned Co2+-excess bimetallic hybrid Co/Zn zeolitic imidazole framework was used to fabricate a composite containing N-doped nanoporous carbon with a rich carbon nanotube (CNT) content on particle surfaces without H2, with the carbon coexisting with Co nanoparticles (NPs) and Co3O4, through controlled carbonization at 800 °C and subsequent oxidation at 250-300 °C. Optimized nanoporous carbon composites were obtained by tracking the formation of Co3O4 and destruction of N-doped nanoporous carbon (NPC) via detailed X-ray diffraction and X-ray photoelectron spectroscopy analysis. The resulting material showed a high surface area of ∼202 m2 g-1 and included coexisting micro- and mesoporous N-doped carbon, CNTs, Co NPs, and Co3O4 (15 nm in size) after a thermal oxidation process in air at 250 °C for 5 h. Surprisingly, the as-prepared MOF-derived nanoarchitecture exhibited superior electrochemical storage performance, with a capacitance of 545 F g-1 within a wide potential window, achieving up to 320% enhanced capacitance compared to that of pristine nanoporous carbon, which is higher than those of most MOF-derived carbons reported so far. Our strategic nanoarchitecture design for MOFs offers a new opportunity for future applications in high performance energy storage systems.
Bibliographical noteFunding Information:
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education (2016R1A6A3A03009359) and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP; Ministry of Science, ICT & Future Planning) (No. 2017R1C1B1007039).
© 2017 The Royal Society of Chemistry.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)