Advances in computational design of van der Waals heterostructures for photocatalytic water splitting

Abstract

Light-driven photocatalytic water splitting is a promising approach to renewable hydrogen production, driven by the increasing global energy demand. van der Waals (vdW) heterostructures have recently emerged as leading materials for next-generation photocatalysts, offering tunable electronic properties and band alignments. This review examines recent progress in vdW heterostructures fabricated from graphitic carbon nitride, transition metal dichalcogenides, black phosphorus, M-Xenes, and layered double hydroxides. We highlight their potential for high solar-to-hydrogen efficiency, facilitated by superior charge separation, enhanced light absorption, and improved carrier utilization. Compared to the type-II mechanism, the direct Z-scheme mechanism in these heterostructures promotes effective electron–hole pair separation, reducing recombination rates and enhancing photocatalytic performance. We also discuss the impact of band gap tunability, stacking patterns, rotational angles, interlayer interactions, and defects in enhancing the efficiency of these heterostructures as photocatalysts. Furthermore, we explore strategies for improving their photocatalytic performance through surface engineering, including doping and co-doping methods. Finally, we examine the potential of machine learning to accelerate the discovery of these heterostructures and propose future research directions for vdW heterostructures in photocatalytic water splitting.