Metal-organic Frameworks Hexagonal Nanoplates: Bottom-up Synthesis, Topotactic Transformation and Efficient Oxygen Evolution Reaction.

Rational design and bottom-up synthesis based on the structural topology is a promising way to obtain two-dimensional metal-organic frameworks (2D MOFs) in well-defined geometric mor-phology. Herein, a topology guided bottom-up synthesis of a novel hexagonal 2D MOF nanoplates is realized. The hexagonal channels constructed via the distorted (3,4)-connected Ni2(BDC)2(DABCO) (BDC = 1,4-benzenedicar-boxylic acid, DABCO = 1,4-diazabicyclo[2.2.2]octane) framework serve as the template for the specifically designed morphology. Under the inhibition and modu-lation of pyridine through a substitution-suppression process, the morphology can be modified from hexagonal nanorods to nano-disks, and to nanoplates with controllable thickness tuned by the dosage of pyridine. Subsequent pyrolysis treatment converts the nanoplates into N-doped Ni@carbon electrocatalyst, which exhibits a small overpotential as low as 307 mV at current density of 10 mA cm‒2 in oxygen evolution reaction (OER).