
Scientific Achievement
The mechanism by which Au nanocages enhance photocatalytic water splitting on MoS2 to produce hydrogen 40X more effectively was revealed using ultrafast pump-probe spectroscopy.
Significance and Impact
Exploiting plasmonic nanomaterials to greatly enhance the activity of photocatalysts presents a new strategy to increase the efficiency of solar energy harvesting and enable practical clean hydrogen production.
Research Details
- Au nanocages with different localized surface plasmon resonances (LSPRs) at 460, 680, and 750 nm were composited with 2D MoS2 flakes for photocatalytic water splitting.
- Au nanocages with LSPR at 680 nm promoted ~40X the photocatalytic rate of 2D MoS2 with absorption edge at ~660 nm.
- Time-resolved transient absorption spectroscopy was conducted to identify the mechanisms behind the Au/MoS2 system.
The near field enhancement governs the LSPR process with the energy of surface plasmon transferred from Au to MoS2 to promote e-h excitation in MoS2, the efficiency of which reaches the maximum when the LSPR wavelength of Au matches the MoS2 absorption edge.
R. Peng, et al., Journal of Materials Chemistry A 11, 16714-16723 (2023). DOI: 10.1039/d3ta01657a
Work performed at the Center for Nanophase Materials Sciences