Electrochemical performance and transformation of Co-MOF/reduced graphene oxide composite

A Co-MOF/reduced graphene oxide (Co-MOF/rGO) composite was prepared, and showed enhanced electrochemical performance compared with bare Co-MOF. Notably, the areas of CV curves witness the increase with the augment of cycle numbers and the redox peaks experience shifts, providing obvious transformation evidence. After a long term transformation process, the composite achieves a pretty high specific capacitance of 1521.6 F g−1 at 0.2 A g−1 and 1117.6 F g−1 even at the high current density of 12 A g−1. This phenomenon could be attributed to the transformation of Co-MOF into CoOOH under the synergy effects of weak alkaline solution and electric field.