Plasmonically pumped WS2 monolayers: Combined experimental and theoretical insights into enhanced photocatalytic hydrogen production

Highly enhanced excitation density in transition metal dichalcogenides through integration with a plasmonic resonator due to the combined effect of Purcell’s enhancement and plasmonic hot electron injection highlights the promise for photocatalytic applications. Here, we report an unambiguous evidence of plasmon-enhanced photocatalytic hydrogen (H2) production from WS2 monolayers integrated with silver (Ag) nano-gratings. The coupling leads to significantly enhanced optical absorption and emission due to a combination of Purcell enhancement and plasmon-induced hot electron generation. Angle-resolved optical spectroscopy is used to identify resonant excitation conditions, which are subsequently employed in photoelectrochemical measurements, demonstrating enhanced photocurrent under resonance. Numerical modeling further confirms strong near-field enhancement and high hot electron density at the WS2/Ag interface. These findings establish plasmonically coupled WS2 platforms as promising candidates for efficient solar-to-H2 generation.