Direct deposition of trivalent rhodium hydroxide into a calcium niobate for photocatalytic hydrogen generation

INOR 66

Hideo Hata, hideo.hata@to.shiseido.co.jp, Material Science Research Center, Shiseido Co., LTD, 2-2-1 Hayabuchi Tsuzuki-ku, Yokohama, Japan and Thomas E. Mallouk, tom@chem.psu.edu, Department of Chemistry and Center for Nanoscale Science, The Pennsylvania State University, University Park, PA 16802.
Well-dispersed Rh(OH)3 nanoparticles were intercalated into the interlayer galleries of a Dion-Jacobson type layered perovskite (ACa2Nb)3O)10 : A = H or K), as confirmed by X-ray diffraction and transmission electron microscopy. Calcination transformed intercalated Rh(OH))3 to Rh2O3 nanoparticles with minimal aggregation. XPS spectra and control experiments with other layered hosts suggest that Rh(OH)3 or Rh2O3 nanoparticles are anchored to the surface of the Ca2Nb3O10 sheets by covalent Nb-O-Rh linkages. Photocatalytic hydrogen evolution from aqueous 10 wt% methanol solutions was investigated with 0.1% Rh(OH)3 or Rh2O3/KCa2Nb3O10 as catalysts. Rh2O3/KCa2Nb3O10 showed a higher hydrogen evolution rate than Rh(OH)3/ or Pt/KCa2Nb3O10. At higher Rh loading, the photocatalytic efficiency decreased substantially because the Rh species absorb UV light. When the interlayer potassium cations of Rh2O3/KCa2Nb3O10 were replaced by protons, the photocatalytic efficiency increased because of the increase in interlayer hydrophilicity.
 

Nanoscience - Characterization and Applications
9:00 AM-1:00 PM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 221, Oral

Division of Inorganic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008