Enabling methanol oxidation by an interacting hybrid nanosystem of spinel Co3O4 nanoparticle decorated MXenes

Abstract

For the successful implementation of direct methanol fuel cells in commercial applications, highly efficient and durable non-noble electrocatalysts based on conducting and stable non-carbonaceous supports can be potential candidates. Herein, spinel Co₃O₄ nanoparticles are decorated over Ti₃C₂ MXene nanosheets for methanol oxidation. The hybrid nanosystem Ti₃C₂/Co₃O₄ (TC) reduces restacking of MXene nanosheets, which offers a larger surface area for Co₃O₄ dispersion, leading to a shorter path for the charge carriers. TC coated on glassy carbon (GC) exhibits a MOR current density of 38.38 A g⁻¹ which is 2.9 times higher than that of Co₃O₄/GC in 1.5 M methanol at a 20 mV s⁻¹ scan rate. The hydrophilic terminations on the surface of MXenes create strong interactions with the Co₃O₄ nanoparticles, which increase the MOR kinetics of the nanocomposite. A low onset potential (0.32 V), high oxidation current density of the nanocomposite, efficient durability and cycling stability up to 200 CV cycles make this nanocomposite a better alternative to the state-of-the-art noble-metal electrocatalysts.