The growing global demand for sustainable energy has heightened the need to develop efficient electrocatalysts for energy conversion processes, particularly the oxygen evolution reaction (OER), which is a key part of water splitting for green hydrogen production. Although a wide range of catalysts has been investigated for use in electrolyser devices, challenges such as cost, conductivity, and stability continue to drive ongoing research in this area.[1]

Transition metal oxide (TMO) materials, despite their great potential as OER catalysts, suffer from limited conductivity, which hampers effective charge transfer during electrochemical processes, and can lead to deactivation due to structural transformations during the OER.MXenes, with their exceptional surface area and conductivity, are promising supports for enhancing the electrocatalytic performance of TMO-based OER catalysts.[2] However, MXenes are susceptible to oxidation under applied potentials, which can alter their structure and properties. By synergistic combination of TMOs with MXenes, a highly efficient OER catalyst could be developed, combining the enhanced conductivity, hydrophilicity, and increased surface area of MXenes with the active OER sites of TMOs.[3] While there have been numerous successful attempts in producing highly performing TMO/MXene composites, the overwhelming number of such reported catalysts is based on the first found and best known Ti₃C₂T_x MXene.[4] This leaves a wide range of potentially highly performing OER catalysts based on MXenes other than Ti₃C₂T_x yet to explore.

In our recent investigations we found that coprecipitation of CoFe layered double hydroxides (LDH) with V₂CT_x MXene at various weight percentages resulted in CoFe/ V₂CT_x composites that outperformed the separate components and physically mixed components as OER catalysts. Furthermore, we could show that the presence of V₂CT_x during the synthesis promotes the formation of a highly active CoFe-LDH phase as opposed to the pure CoFe sample. We further investigated the materials’ oxidation states under OER conditions via synchrotron based in-situ XAS to detect the catalytically active species for the OER.

These findings demonstrate the great potential of TMO/ V₂CT_x composites as OER electrocatalysts and are a step towards understanding the reasons for their improved catalytic activity.