Ajay P Manuel1, Karthik Shankar1,2. 1. Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada. 2. Future Energy Systems Research Institute, University of Alberta, Edmonton, AB T6G 1K4, Canada.
Abstract
Plasmonic photocatalysis enables innovation by harnessing photonic energy across a broad swathe of the solar spectrum to drive chemical reactions. This review provides a comprehensive summary of the latest developments and issues for advanced research in plasmonic hot electron driven photocatalytic technologies focusing on TiO2-noble metal nanoparticle heterojunctions. In-depth discussions on fundamental hot electron phenomena in plasmonic photocatalysis is the focal point of this review. We summarize hot electron dynamics, elaborate on techniques to probe and measure said phenomena, and provide perspective on potential applications-photocatalytic degradation of organic pollutants, CO2 photoreduction, and photoelectrochemical water splitting-that benefit from this technology. A contentious and hitherto unexplained phenomenon is the wavelength dependence of plasmonic photocatalysis. Many published reports on noble metal-metal oxide nanostructures show action spectra where quantum yields closely follow the absorption corresponding to higher energy interband transitions, while an equal number also show quantum efficiencies that follow the optical response corresponding to the localized surface plasmon resonance (LSPR). We have provided a working hypothesis for the first time to reconcile these contradictory results and explain why photocatalytic action in certain plasmonic systems is mediated by interband transitions and in others by hot electrons produced by the decay of particle plasmons.
Plasmonic photocat<n class="Chemical">spanpan> class="Chemical">alpan>>ysis enables innovation by harnessing photonic energy across a broad swathe of the solar spn>ectrum to drive chemic<span class="Chemical">al reactions. This review provides a <span class="Chemical">comprehensive summary of the latest developments and issues for advanced research in plasmonic hot electron driven photocat<span class="Chemical">alytic technologies focusing on TiO2-noble metal nanoparticle heterojunctions. In-depth discussions on fundamental hot electron phenomena in plasmonic photocatalysis is the focal point of this review. We summarize hot electron dynamics, elaborate on techniques to probe and measure said phenomena, and provide perspective on potential applications-photocatalytic degradation of organic pollutants, CO2 photoreduction, and photoelectrochemicalwater splitting-that benefit from this technology. A contentious and hitherto unexplained phenomenon is the wavelength dependence of plasmonic photocatalysis. Many published reports on noble metal-metal oxide nanostructures show action spectra where quantum yields closely follow the absorption corresponding to higher energy interband transitions, while an equal number also show quantum efficiencies that follow the optical response corresponding to the localized surface plasmon resonance (LSPR). We have provided a working hypothesis for the first time to reconcile these contradictory results and explain why photocatalytic action in certain plasmonic systems is mediated by interband transitions and in others by hot electrons produced by the decay of particle plasmons.
Entities:
Keywords:
Schottky barrier; TiO2; charge transfer; hot electron; nanoparticles; optical resonances; oxide interfaces; photoreduction; plasmon; solar energy conversion
Authors: Yurui Fang; Yang Jiao; Kunli Xiong; Robin Ogier; Zhong-Jian Yang; Shiwu Gao; Andreas B Dahlin; Mikael Käll Journal: Nano Lett Date: 2015-05-06 Impact factor: 11.189