In the search for novel efficient photocatalysts for the conversion of CO2 into fuels, plasmonic photocatalysts based on the self-assemblies of silver or gold nanoparticles with [Zn3Ga(OH)(8)](2)CO3 center dot mH(2)O layered double hydroxide (Zn3Ga vertical bar CO3 LDH) were prepared and tested for the photoreduction of CO2 by H-2 under irradiation with UV-visible light. Ag and Au nanoparticles were obtained directly on the LDHs via the ion-exchange method or the reconstruction method of the LDHs. The catalysts exhibited intense surface plasmon resonance (SPR) effect at 411 and 555 nm attributable to Ag and Au nanoparticles, respectively. The rate of CO2 photoreduction on Ag/Zn3Ga vertical bar CO3 increased by a factor of 1.69 than that of Zn3Ga vertical bar CO3 while the methanol selectivity also increased from 39 to 54 mol%. On Au/Zn3Ga vertical bar CO3, the reduction rate of CO2 was 1.78 times higher than on Zn3Ga vertical bar CO3 LDH whereas the methanol selectivity decreased from 39 to 13 mol%. Electron microscopy and UV-visible and X-ray spectroscopy detected particular interactions of the cationic layers of Zn3Ga vertical bar CO3 with Ag and Au nanoparticles. Results show that for Ag/Zn3Ga vertical bar CO3 catalysts, CO2 photoreduction by H-2 under visible light was promoted by the SPR effect of Ag nanoparticles while for Au/Zn3Ga vertical bar CO3 catalysts Au nanoparticles might act as electron-trapping active sites. (C) 2014 Elsevier B.V. All rights reserved.