Porosity‐Engineering of MXene as a Support Material for a Highly Efficient Electrocatalyst toward Overall Water Splitting

The use of 2 D transition metal carbide MXenes as support materials to incorporate catalytically active compounds is of interest because of their unique properties. However, the preparation of well‐dispersed catalytic phases on the inter‐connected porous MXene network is challenging and has been rarely explored. This work focuses on the synthesis of basal‐plane‐porous titanium carbide MXene (ac‐Ti3C2) that is used subsequently as an effective host for the incorporation of a known catalytically active phase (IrCo) as an effective bifunctional electrocatalyst toward water splitting. The porous ac‐Ti3C2 with abundant macro/meso/micropores is prepared by a wet chemical method at room temperature and provides ideal anchor sites for intimate chemical bonding with alien compounds. The resulting IrCo@ac‐Ti3C2 electrocatalyst exhibits an excellent reactivity (220 mV at 10 mA cm−2) towards the oxygen evolution reaction in 1.0 m KOH, which surpasses that of the benchmark RuO2, a low voltage cell of 1.57 V (@ 10 mA cm−2) and good long‐term durability. Our work demonstrates the effectiveness of porosity engineering in MXene nanosheets as a support material to shorten ion migration pathways, to increase electrolyte accessibility between inter‐sheets and to overcome inherited re‐stacking and aggregation issues. Pores for thought: Porous nanostructured titanium carbide MXene (ac‐Ti3C2) possesses plenty of coexisting micro/meso/macropores and low‐coordinate defect sites on its basal plane. This material is used to support electrochemically active bimetallic IrCo. The IrCo@ac‐Ti3C2 electrocatalyst exhibits an excellent reactivity in the oxygen evolution reaction and overall water splitting.