Effective enhancement of capacitive performance by the facile exfoliation of bulk metal–organic frameworks into 2D-functionalized nanosheets

Recently, much attention has been paid to two-dimensional MOF nanosheets (MONs) due to their widespread application in many specific areas. In this work, a simple and efficient congenerous-exfoliation strategy was developed to prepare vast and uniform few-layered Ni²⁺@Ce-MOF (Ce-MOF: {[Ce(HPIA)(PIA)(H₂O)₂]·H₂O}_n) nanosheets with a thickness of ca. 10 nm. In the exfoliation process, the synergistic action of Ni²⁺ and methanol solvents under ultrasonication plays a major role in restraining the interactions between the layers. Importantly, supercapacitor applications indicate that the exfoliated Ni²⁺@Ce-MOF nanosheet shows a remarkable improvement in the specific capacitance (921.05%) in comparison with that of the bulk Ce-MOF sample before modification.