Metal-Organic Gels of Tris-tetrazole-tri-amido Molecule with Co(II) and Ni(II) as Effective Electrocatalysts for Oxygen Evolution Reaction: Effect of Metal Ion, Porosity and Morphology on the Catalytic Activity of MOGs

Development of efficient and low cost electrocatalysts has been an important area of research in the field of materials chemistry. In this regard metal-organic gels (MOGs) are one of the promising materials and they are being utilized for various materials applications including energy conversion and storage. Electrochemical applications of the MOGs are still in its infancy and further studies are required for exploration of structure-property correlation that is crucial for targeted and efficient materials design. Herein we report multi stimuli responsive MOGs containing a tris-tetrazole-tri-amido based organic ligand. The self-assembly of the threefold symmetric ligand with Co(II)/Ni(II) acetates results in the MOGs with distinct morphological and structural characteristics, regardless of containing the same organic ligand. These MOGs were synthesized by direct mixing of the precursors under ambient conditions. The xerogels of these MOGs (Co-MOG & PRIME; and Ni-MOG & PRIME;) exhibit excellent OER performance as the Co-MOG & PRIME; and Ni-MOG & PRIME; shows the overpotential of 312 mV and 418 mV at 10 mA/cm(2) in an alkaline electrolyte. Electrocatalytic performance of the xerogels were correlated to their structural features like distinct morphology and porosity of the material that facilitates the mass transfer and maximum exposure to the electrochemical active sites. Importantly, this work demonstrates the functional application of MOGs as electrocatalysts for OER and the effect of metal ion, porosity and morphology on their overall performance.