Solvent regulation strategy of Co-MOF-74 microflower for supercapacitors

Metal-organic frameworks (MOFs) with porous crystal structures have attracted extensive attention in application of energy storage and conversion, owing to their regularity, porosity, large specific surface area, etc. In this work, Co-MOF-74 microflower has been successfully prepared via a controllable solvent regulation strategy. Through modulating the polarity of the solvent, crystals grow in certain preferred orientation and Co-MOF-74 with various morphologies were obtained. Thereinto, the energy storage performance of Co-MOF-74 microflower was measured in both three-electrode system and asymmetric supercapacitor device (specific capacitance of 164.2 F/g at 0.5 A/g in the three-electrode system and 62.5 F/g at 1 A/g in the asymmetric supercapacitor device). This can be attributed to the preferred crystal orientation resulting in a regular and uniform microflower, which is of great significance to electronic interfacial exchange and ion transfer during electrochemical reactions.