Plasmonic Heterosturcture for Full Solar Spectrum Harvesting

Abstract

Clean chemical fuel (hydrogen) generation from water using heterogeneous photocatalysts is an emerging technology for sustainable energy research. However, photo-to-hydrogen conversion efficiency of benchmarking photocatalysts still appear to be far from practice due to their limited light absorption of solar irradiation spectrum (UV-vis-NIR) and poor excited carrier lifetime. There is, therefore, an increasing interest in developing high efficiency photocatalysts with a broad spectral response and efficient excited carriers separation. In this work, a novel MoS2@TiO2 heterostructured film with periodically patterned morphology, exhibiting an enhanced light absorption within UV-vis-NIR wavelengths, was developed. Both experimental studies and theoretical modeling demonstrate that S-vacancy in the multilayered MoS2 nanoflakes is responsible for the localized surface plasmon resonance (LSPR, visible light absorption) and tunable band gaps (near infrared absorption). An outstanding H2 yield rate of 580 mmol h-1 g-1 was then achieved using the rationally designed novel MoS2@TiO2 photocatalyst. Present study also shows that the developed catalyst can even split sea water under solar light irradiation, which will open a new paradigm for direct solar energy harvesting.