• 文献标题:   CVD grown nitrogen doped graphene is an exceptional visible-light driven photocatalyst for surface catalytic reactions
  • 文献类型:   Article
  • 作  者:   ALAM KM, KUMAR P, MANUEL AP, VAHIDZADEH E, GOSWAMI A, ZENG S, WU WJ, MAHDI N, CUI K, KOBRYN AE, GUSAROV S, SONG YN, SHANKAR K
  • 作者关键词:   exciton plasmon coupling, hot electron injection, plasmon induced resonance energy transfer, photoreduction, fdtd simulation, plasmonic catalysi, van der waals material
  • 出版物名称:   2D MATERIALS
  • ISSN:   2053-1583
  • 通讯作者地址:   Univ Alberta
  • 被引频次:   2
  • DOI:   10.1088/2053-1583/ab4554
  • 出版年:   2020

▎ 摘  要

The photocatalytic potential of large area CVD grown nitrogen doped graphene (NGr) has been explored though the chemical transformation of 4-nitrobenzene thiol into p,p'-dimercaptoazobenzene. Decoration of NGr with Ag nanocubes with rounded edges to form NGr/Ag nanohybrids resulted in a slight increase in the work-function and a decrease in the n-type character of NGr due to ground state transfer of negative charge from NGr to Ag. The Ag nanocubes exhibited a localized surface plasmon resonance (LSPR) at -425 nm. When the NGr/Ag nanohybrids were illuminated with visible light of wavelength close to the LSPR peak, Kelvin probe force microscopy (KPFM) indicated a dramatic change in surface potential of -225 mV and Raman spectra detected electron accumulation in NGr, which are attributed to a high local field enhancement-mediated hot electron injection into NGr and the formation of long-lived charge separated states. Pristine nitrogen doped graphene and its coupled system with plasmonic Ag nanoparticles showed superior photocatalytic performance compared to bare plasmonic Ag catalyst. While standalone Ag NPs were unable to complete the transformation of 4-NBT into DMAB even at a laser power of 10 mW, NGr/Ag nanohybrids completed this transformation at a laser power of 1 mW, pointing to the high photoreduction strength of NGr/Ag. Density functional theory (DFT) based computational modeling was used to examine the electronic structure of graphene doped with graphitic, pyridinic and pyrrolic nitrogen dopant atoms. DFT results indicated an enhanced chemical reactivity of NGr due to stronger localization of charge at the dopant sites and a pronounced difference in the projected density of states (PDOS) for carbon atoms in proximity to, and distant from, the nitrogen dopant sites.