Mechanistic insight into bimetallic CoNi-MOF arrays with enhanced performance for supercapacitors
Chu, Meng, Deng, Lu, Bondarchuk, Sui, Feng, Li, Zhang (2020) Mechanistic insight into bimetallic CoNi-MOF arrays with enhanced performance for supercapacitors Nanoscale (IF: 6.7) 12(9) 5669-5677Abstract
Engineering multicomponent electroactive materials is an effective strategy to improve electrochemical performance by adjusting the atomic and electronic structure. In this work, we directly synthesize oriented bimetallic CoNi-MOF nanosheets on CFP (carbon fiber paper). The CoNi-MOF/CFP shows high specific capacitance, outstanding rate capability and long-term cycling stability compared to a monometallic Ni-MOF or Co-MOF. By adjusting the Co/Ni molar ratio, CoNi23/CFP (Co : Ni = 2 : 3) displays the highest specific capacitance (2033 F g-1 at 1 A g-1). The introduction of Co into the Ni-MOF matrix shortens Co/Ni-centered bond distances, resulting in improved bond strength, facilitating the charge transfer and increasing the electrical conductivity of the CoNi-MOF, which were proved by X-ray absorption fine structure (XAFS) spectroscopy, high angle annular dark field (HAADF) imaging, and electrochemical impedance spectroscopy (EIS). Our study demonstrates the origin of performance improvements and, therefore, may provide a feasible scheme to unlock high-performance MOF electrode materials.
Links
http://www.ncbi.nlm.nih.gov/pubmed/32101234http://dx.doi.org/10.1039/c9nr10473a
