From 1D to 2D: Controllable Preparation of 2D Ni–MOFs for Supercapacitors

Controllable modulation strategies between one-dimensional (1D) and two-dimensional (2D) structures have been rarely reported for metal-organic frameworks (MOFs). Here, 1D, 1D/2D, and 2D Ni-MOFs can be facilely prepared by adjusting the ratio of Ni²⁺ and the pyromellitic acid linker. A low-dimensional structure can shorten the transmission distance, while MOFs with a high Ni²⁺ content can supply rich active sites for oxidation-reduction reactions. The 2D structure Ni-MOF with an optimized Ni²⁺/pyromellitic acid ratio presents a good performance of 1036 F g^-1 at a current density of 1 A g^-1 with a comparable rate performance of 62% at 20 A g^-1. The study may offer a facile design to control the structure of MOFs for employing in electrochemical energy storage.