Self-supporting heterostructured electrode via in-situ conversion: Short rod-like Ni-Fe carbonate hydroxides/conductive MOFs synergy for efficient oxygen evolution

Abstract

The low electron conductivity of transition metal carbonate hydroxides (TMCHs) makes their oxygen evolution reaction (OER) activities being far from meeting the requirements of practical application. In this work, a short rod-like self-supporting heterostructured electrode is fabricated by in-situ conversion of Ni-Fe carbonate hydroxide to NiFe-based conductive metal-organic frameworks (c-MOFs). Thanks to the unique short rod-like heterostructure, more catalytic active sites can be exposed, and electron transfer at the heterogeneous interface regulates the electronic structure of the active center. The electrode exhibits an excellent catalytic activity with an overpotential of only 235 mV at 10 mA cm⁻² in 1.0 M KOH and excellent stability at multiple current densities from 10 mA cm⁻² to 50 mA cm⁻² toward the OER.