Au-Ag alloy nanoparticles supported on ordered mesoporous carbon (CMK-3) with remarkable solar thermal conversion efficiency

摘要

Dual plasmonic Au-Ag alloy nanoparticles supported on ordered mesoporous carbon (Au-Ag/CMK-3) have been fabricated by the method of partial substitution of silver on CMK-3 with gold. Near-spherical Ag-Au nanoparticles with a diameter of 8-15nm are uniformly coated on the surface of CMK-3. Attributed to dual localized surface plasmon resonance (LSPR) effect of Au-Ag alloy nanoparticles, the Au-Ag/CMK-3 composites have remarkable broadband absorption in the visible and near-infrared regions. All CMK-3 based nanofluids show much higher photothermal conversion efficiency than the base liquid of ethylene glycol (EG). Au-Ag alloy nanoparticles further enhance the photothermal conversion efficiency of CMK-3, which is 71.1% compared with 67.4% and 65.6% for Au/CMK-3 and Ag/CMK-3, respectively. The Au-Ag/CMK-3 nanomaterials pay new ways for fabrication promising photothermal nanofluids for application in direct absorption solar collectors.