Strategic enhancement in charge carrier dynamics of photoactive Fe2O3 by decorating WS2 nanosheets for enhanced photoelectrochemical water splitting

Hematite (Fe 2 O 3 ) is a promising photoactive material for solar-driven hydrogen production, but its photoelectrochemical (PEC) efficiency is limited by rapid charge recombination and a short hole diffusion length. To address these challenges, this study synthesized α-Fe 2 O 3 nanoparticles via a hydrothermal method and deposited WS 2 nanosheets onto their surface using RF-magnetron sputtering, forming α-Fe 2 O 3 /WS 2 heterostructures (FW-HS 10). The WS 2 deposition time was systematically varied to optimize charge-carrier dynamics and PEC activity. Characterization by XRD, Raman spectroscopy, FE-SEM, HR-TEM, and EDS confirmed the successful fabrication and strong interfacial contact between WS 2 and Fe 2 O 3 . Among all samples, the FW-HS 10 photoanode (10 min WS 2 deposition) exhibited the highest PEC performance, delivering a photocurrent density of 3.69 mA cm -2 at 0.7 V vs. SCE, 12 times higher than pristine WS 2 and 7 times greater than pristine Fe 2 O 3 . The applied-bias photon-to-current efficiency reached 0.85% at 0.60 V vs. SCE, representing 42- and 77-fold improvements over the pristine materials. These results demonstrate that the α-Fe 2 O 3 /WS 2 heterojunction effectively enhances charge separation and transport, making the optimized FW-HS 10 photoanode a strong candidate for efficient solar-driven hydrogen production.