# Facile synthesis of a novel Co–Ba–TPA MOF exhibiting nearly identical overpotential for electrochemical production of hydrogen and oxygen

## TL;DR

A new metal-organic framework (Co–Ba–TPA MOF) is developed that efficiently catalyzes both hydrogen and oxygen production with nearly equal efficiency.

## Contribution

The synthesis of a novel Co–Ba–TPA MOF with nearly identical overpotentials for HER and OER is presented.

## Key findings

- The Co–Ba–TPA MOF shows overpotentials of 414.5 mV for HER and 412.6 mV for OER at 10 mA cm−2.
- The MOF maintains OER performance at higher current densities up to 100 mA cm−2.
- The catalyst eliminates the usual trade-off between HER and OER activities.

## Abstract

In this study, the successful synthesis and comprehensive characterization of a novel cobalt–barium–terephthalic acid metal–organic framework (Co–Ba–TPA MOF) as a high-performance bifunctional electrocatalyst is reported. The prepared MOF exhibits synergistic interactions between Co and Ba metal centers within the terephthalic acid framework to exhibit an optimized electronic environment for enhanced electrocatalytic performance. Structural characterization through XRD, SEM and FTIR confirmed successful framework formation, while electrochemical evaluation revealed exceptional bifunctional activity with almost identical overpotential across both water splitting half-reactions. The MOF demonstrates an overpotential of 414.5 mV and 412.6 mV at 10 mA cm−2 for HER and OER maintaining a Tafel slope of 145.23 mV dec−1 and 106.18 mV dec−1, respectively. The OER performance is preserved up to higher current densities (e.g. 100 mA cm−2), which makes it possibly applicable for industrial applications. The almost identical overpotentials for both reactions represent a commendable achievement in bifunctional catalyst design by eliminating the typical trade-off between HER and OER activities shown by most single-metal catalysts and offering an alternative to expensive platinum-group metals while maintaining competitive electrocatalytic performance.

Co–Ba–TPA metal–organic framework demonstrates efficient bifunctional electrocatalytic performance for both hydrogen evolution reaction (HER, 414.5 mV) and oxygen evolution reaction (OER, 412.6 mV) in 1.0 M KOH alkaline electrolyte.