China Nonferrous Metallurgy

The oxygen evolution reaction （OER） is a key step in the electrolytic hydrogen production process， and its electrocatalytic performance is highly dependent on the composition and crystal plane structure of the catalyst. Metal-organic frameworks （MOFs） have demonstrated great potential in the field of electrocatalysis； however， their catalytic activity is limited by poor electrical conductivity， insufficient structural stability， and low utilization of active sites. In this study， based on interfacial regulation and conductive medium integration， a composite catalyst （C@Co-MOF） was prepared by incorporating nano carbon powder （C） into a cobalt-based metal – organic framework （Co-MOF） via a mechanical grinding method. The obtained samples were systematically characterized and evaluated for their electrochemical performance， leading to the following main conclusions. Research shows that the introduction of nano-carbon powder （C） can effectively enhance the conductivity of MOF， thereby enabling it to exhibit excellent catalytic properties. It was also found that by regulating the mass fraction of nano-carbon powder （C）， the crystal plane structure exposed by Co-MOF could be regulated to a certain extent. Appropriate doping of C will not destroy the crystal phase structure of Co-MOF， but it can effectively inhibit the growth of the （002） and （310） crystal planes， thereby promoting the exposure of the highly active （110） and （300） crystal planes. 5%C@Co-MOF exposes more （110） and （300） crystal planes， thus showing the best OER performance， with an overpotential of only 270 mV at a current density of 10 mA cm^-2 . This study proposes a green and simple crystal plane engineering strategy， providing new ideas and practical paths for the development of high-performance and low-cost electrocatalysts.