Transition-metal-based metal–organic frameworks (MOF) acquire great interest for the development of low cost, platinum-free, nonprecious water splitting electrocatalysts for hydrogen generation to meet the energy crisis. Recent studies are mainly concerned with the use of MOF as self-sacrificing template for the synthesis of carbon-based electrocatalysts encapsulating metallic sites. However, the process often produces undesired metal nanoparticles, lowering the catalytic activity of the materials. This report explores a novel strategy to improve the electrocatalytic activity of intrinsic MOF by ligand substitution method. Ligands with different electron donating capacity have been used for substitution process and the hydrogen evolution activity has been found to be greatly affected by the presence of different donor ligands. The MOF used in this work is designed with Ni as metal center with 5-azido isophthalic acid as the primary linker. Subsequently, the MOF is functionalized with different organic moieties i.e. N, N di methyl ethylene di amine (DMEDA), 4-amino tetra fluoro pyridine (4-ATFP) with rich non-metal catalytic active sites by means of post synthetic modification. A comparative study has been performed which shows 4-ATFP functionalized MOF to have best electrocatalytic activity among the three with significant performance in all three i.e. neutral, acidic, alkaline mediums. Furthermore, theoretical approaches have been employed for the analysis of these experimental observations.

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