2D mesh PPy facilitates Ni-based MOF electron modulation and transfer for enhancing electrocatalytic total water dissociation

Abstract

Reducing the overpotentials of HER and OER is an effective approach for decreasing the cost of hydrogen production. Electrolytic water catalysts with enhanced performance has been a significant research focus for utilizing hydrogen energy. In this work, the synergistic effect of organic polymer materials and inorganic materials was utilized to prepare a reticulated catalyst (NiZn/PPy) with a fibrous PPy substrate modified with bimetallic MOF spheres, which exhibits good HER and OER properties. Its special fiber mesh structure reduces catalyst agglomeration, which exposes more active sites for improving the stability of the catalyst over extended periods of time. Furthermore, the incorporation of PPy results in an increase in pyrrole-N, pyridine-N, and graphite-N structures, leading to a greater number of reactive active sites. The construction of bimetallic MOFs modulates the valence state of the active site, thereby accelerating electron transfer during the reaction. The synergistic interaction among the components resulted in an HER overpotential of only 76 mV at 10 mA cm⁻² and an OER overpotential of only 373 mV at 100 mA cm⁻² in a 1 M KOH solution, achieving a total dissolved water overpotential of 1.605 V.