Interfacial engineering and rapid thermal crystallization of Sb2S3 photoanodes for enhanced photoelectrochemical performances

초록

Antimony sulfide (Sb2S3) is a promising material for photoelectrochemical (PEC) devices that generate green hydrogen from sunlight and water. In this study, we present a synthesis of high-performance Sb2S3 photoanodes via an interface-engineered hydrothermal growth followed by rapid thermal annealing (RTA). A TiO2 interfacial layer plays a crucial role in ensuring homogeneous precursor deposition, enhancing light absorption, and forming efficient heterojunctions with Sb2S3, thereby significantly improving charge separation and transport. RTA further improves crystallinity and interfacial contact, resulting in dense and uniform Sb2S3 films with enlarged grains and fewer defects. The optimized Sb2S3 photoanode achieves a photocurrent density of 2.51 mA/cm2 at 1.23 V vs. the reversible hydrogen electrode (RHE), one of the highest reported for Sb2S3 without additional catalysts or passivation layers. To overcome the limitations of oxygen evolution reaction (OER), we employ the iodide oxidation reaction (IOR) as an alternative, significantly lowering the overpotential and improving charge transfer kinetics. Consequently, it produces a record photocurrent density of 8.9 mA/cm2 at 0.54 V vs. RHE. This work highlights the synergy between TiO2 interfacial engineering, RTA-induced crystallization, and IOR-driven oxidation, offering a promising pathway for efficient and scalable PEC hydrogen production. © 2025 Science Press

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