Near-field assisted visible- and infrared-light water splitting

To improve the efficiency of solar light utilization for water splitting, an optical near-field (ONF)-assisted photocatalyst reaction was carried out with a ZnO photocatalyst. The dependence of the photocurrent on the excitation power indicated that two-step visible light excitation occurred in a ONF-assisted process. A photoluminescence measurement also supported the conclusion that the visible light excitation originated from ONF excitation, not from defect states in the ZnO nanorod photocatalyst. This phonon-assisted excitation process can be applied not only for ZnO but also for other semiconductor materials, which will allow higher efficiency of hydrogen generation using sunlight to be realized.

Related publications

  1. T. Yatsui, T. Imoto, T. Mochizuki, K. Kitamura, and T. Kawazoe, “Dressed-photon–phonon (DPP)-assisted visible- and infrared-light water splitting,” Scientific Reports, Vol. 4, April 2014, Article number: 4561, doi:10.1038/srep04561 (5 pages)
  2. H.H. Le, K. Mawatari, Y. Pihosh, T. Kawazoe, T. Yatsui, M. Ohtsu, and T. Kitamori, “Novel Sub-100 nm Surface Chemical Modification by Optical Near-field Induced Photocatalytic Reaction,” Microfluidics and Nanofluidics, Volume 17, Issue 4, October 2014, pp. 751-758, DOI:10.1007/s10404-014-1361-7
  3. T. H. H. Le, K. Mawatari, Y. Pihosh, T. Kawazoe, T. Yatsui, M. Ohtsu, M. Tosa, and T. Kitamori, “Optical near-field induced visible response photoelectrochemical water splitting on nanorod TiO2,” Appl. Phys. Lett., Vol. 99, Issue 21, November 2011, 213105 (3 pages) (selected for Virtual Journal of Nanoscale Science & Technology — December 5, 2011, Volume 24, Issue 23).