MXene’s value addition role as photo/ electrocatalysts in water splitting for sustainable hydrogen production

Abstract

The energy transition from fossil fuel-based to renewable energy is a global agenda. At present, two major concerns in the green hydrogen economy are the demand for clean fuel, and non-noble materials to produce hydrogen through water electrolysis. Researchers are focusing on addressing these issues together with the help of the development of appropriate non-noble-based photo/electrocatalytic materials. A new class of two-dimensional materials, MXenes, has recently shown the tremendous potential for water splitting to produce H2 through a photoelectrochemical process. The unique properties of emerging 2D MXenes materials, such as hydrophilic surface functionalities, greater surface-to-volume ratio, and inherent flexibility, attract these materials as appropriate photo/electrocatalytic materials. Unique value addition and innovative strategies like the introduction of end-group modification, heterojunctions, and nanostructure engineering have shown the potential of MXene materials as emerging photo/electrocatalysts for water splitting. When integrated with conventional noble metal catalysts, MXene-based catalysts have demonstrated a lower overpotential for hydrogen and oxygen evolution reactions and a remarkable boost in performance for enhanced H2 production rates surpassing those of pristine noble metal-based catalysts. These promote future perspectives for the utilization of chemically synthesized MXenes as alternative photo/electrocatalysts. This review highlights the recent five years' progress on fundamental mechanisms and issues associated with water splitting, influencing factors of MXene, value addition role, and application strategies for water splitting including performance, challenges, and outlook of MXene-based electro/photocatalysts.