Design of Plasmonic Catalysts Utilizing Nanostructures

This review describes the design of nanostructured plasmonic catalysts, such as nanoparticles and nanosheet morphologies, that strongly absorb visible light over a wide range of the solar spectrum due to localized surface plasmon resonance (LSPR) and application to enhanced hydrogen evolution. A new method for the synthesis of Ag nanoparticles, with color dependent on the particle size and morphology, combined microwave heating and the use of mesoporous silica materials. Further combination with Pd nanoparticles significantly enhanced the catalytic activities for hydrogen production from ammonia borane (NH3BH3) compared with the inherent Ag catalysts under both dark and visible-light irradiation conditions. We also describe the synergistic catalysis activities of plasmonic Au(core)–Pd(shell) nanoparticles supported on amine-functionalized metal-organic frameworks (MOFs) for boosting room-temperature hydrogen production from formic acid (HCOOH) under visible light irradiation. Our search for plasmonic materials based on earth abundant elements found that reduced molybdenum oxide (HxMoO3−y) nanosheet with oxygen defects and doped hydrogen displayed intense absorption in a wide range from the visible to the near-infrared region. This unique plasmonic HxMoO3−y nanosheet can enhance dehydrogenation from ammonia borane under visible light irradiation.