Highly Efficient Overall Photocatalytic Water Splitting in 2d Heterostructure Gase/Scgase3

Abstract

Photocatalytic water splitting technology, an eco-friendly and highly promising approach to green hydrogen generation, holds the pivotal key to environmental sustainability and efficient energy harnessing. At its heart lies the quest for ultra-efficient catalysts. In this work, we have delicately designed a type-II band-aligned GaSe/ScGaSe3 heterostructure, meticulously examining its photocatalytic prowess through rigorous first-principles calculations. Remarkably, the GaSe/ScGaSe3 heterostructure exhibits a minimal indirect bandgap (0.44 eV) due to interlayer interactions, ensuring efficient photocatalytic water splitting reactions across all pH values under the action of the inherent built-in electric field. Furthermore, the heterostructure shines with exceptional optical properties, exhibiting a high light absorption coefficient that captures an impressive 15% to 43% of visible and ultraviolet light, dramatically bolstering sunlight utilization efficiency. Encouragingly, our analysis reveals a staggering corrected solar-to-hydrogen (STH) efficiency of 31.38% for this heterostructure, marking a colossal 351% leap over standalone GaSe monolayer. Moreover, the application of biaxial tensile strain elevates this efficiency even further, to an astounding 35.74%. These remarkable attributes not only underscore the immense potential and promising applications of GaSe/ScGaSe3 heterostructure in photocatalytic water splitting but also serve as a robust scientific cornerstone and experimental roadmap for the advancement of innovative and high-performance photocatalysts in the future.

Keywords: Two-dimensional materials, Intrinsic electric field, Solar-to-hydrogen, Photocatalytic water splitting, First-principles calculations