Two-dimensional materials for photoelectrochemical water splitting

Abstract

Two-dimensional (2D) materials have sparked in-depth research in various fields due to their entirely distinct electronic and mechanical properties compared to their bulk counterpart. In a photoelectrochemical cell, 2D materials can serve crucial roles by incorporating their unique and extraordinary characteristics into semiconducting photoabsorbers to boost the unassisted solar water splitting. To this end, this review summarizes the intrinsic superiorities of 2D materials derived using van der Waals interactions between individual layers and presents the utilization of 2D materials to improve the photoelectrochemical performance of photoelectrodes. In addition, the emerging state-of-the-art 2D materials, including transition metal dichalcogenides (TMDs), graphene, graphdiyne, black phosphorus (BP), layered double hydroxides (LDHs), g-C₃N₄, and MXenes, will be introduced. Delicately constructed heterostructures with photoabsorbers and 2D materials are capable of highly efficient light harvesting for both hydrogen and oxygen evolution. Finally, critical outlooks on developing synthetic technology for mass production, improving stability issues, and constructing tandem architectures for unbiased solar water splitting will be discussed.