Progress and prospects of MXene-based bifunctional electrocatalysts for overall water splitting in alkaline media

Abstract

The quest to find a low-cost, sustainable, and active electrocatalyst for water splitting has garnered significant research interest. Transition metal-based bifunctional electrocatalysts, embodying an array of outstanding compounds such as oxides, (oxy)/hydroxides, chalcogenides, and phosphides have emerged as potential candidates in water splitting. Nonetheless, limited conductivity, poor stability, and self-agglomeration tendency have hampered their overall efficacy. Integration of MXene with these active materials has a breakthrough solution. The electronic conductivity of MXene, coupled with the surface reactive moieties aiding the electrostatic anchoring of active species, and the layered structure magnifying the electrochemical surface area, synergistically boost the water-splitting process. This review aims to provide an in-depth understanding of the mechanisms involved in the electrolysis process, emphasizing the advantages of utilizing alkaline media. With this comprehensive review, we delve into the frontline development of these MXene-based bifunctional electrocatalysts systematically surveying their electrocatalytic potential in alkaline media. We have also highlighted key challenges in adopting MXene-based electrocatalysts with future opportunities for the advancement of MXene-based electrocatalysts.