title: Enhanced photocatalytic performance at a Au/N-TiO₂ hollow nanowire array by a combination of light scattering and reduced recombination.
abstract: We demonstrate one-step gold nanoparticle (AuNP) coating and the surface nitridation of TiO2 nanowires (TiO2-NWs) to amplify visible-light photon reflection. The surface nitridation of TiO2-NW arrays maximizes the anchoring of AuNPs, and the subsequent reduction of the band gap energy from 3.26 eV to 2.69 eV affords visible-light activity. The finite-difference time-domain (FDTD) simulation method clearly exhibits the enhancement in the strengths of localized electric fields between AuNPs and the nanowires, which significantly improves the photocatalytic (PC) performance. Both nitridation and AuNP decoration of TiO2-NWs result in beneficial effects of high (e(-)/h(+)) pair separation through healing of the oxygen vacancies. The combined effect of harvesting visible-light photons and reducing recombination in Au/N-doped TiO2-NWs promotes the photocatalytic activity towards degradation of methyl orange to an unprecedented level, ∼4 fold (1.1 × 10(-2) min) more than does TiO2-NWs (2.9 × 10(-3) min(-1)). The proposed AuNP decoration of nitridated TiO2-NW surfaces can be applied to a wide range of n-type metal oxides for photoanodes in photocatalytic applications.
authors.affiliation: Department of Energy Engineering, Hanyang University, Seoul 133-791, Korea. upaik@hanyang.ac.kr kangys@hanyang.ac.kr.
authors.forename: P
authors.initials: P
authors.lastname: Sudhagar
authors.forename: Anitha
authors.initials: A
authors.lastname: Devadoss
authors.forename: Taeseup
authors.initials: T
authors.lastname: Song
authors.forename: P
authors.initials: P
authors.lastname: Lakshmipathiraj
authors.forename: Hyungkyu
authors.initials: H
authors.lastname: Han
authors.forename: Volodymyr V
authors.initials: VV
authors.lastname: Lysak
authors.forename: C
authors.initials: C
authors.lastname: Terashima
authors.forename: Kazuya
authors.initials: K
authors.lastname: Nakata
authors.forename: A
authors.initials: A
authors.lastname: Fujishima
authors.forename: Ungyu
authors.initials: U
authors.lastname: Paik
authors.forename: Yong Soo
authors.initials: YS
authors.lastname: Kang
mesh_terms: D002384:Catalysis / Q000528:radiation effects; D006046:Gold / Q000737:chemistry* / Q000528:radiation effects; D008027:Light; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000528:radiation effects; D058608:Nanopores / Q000648:ultrastructure*; D053770:Nanowires / Q000737:chemistry* / Q000528:radiation effects; D010084:Oxidation-Reduction / Q000528:radiation effects; D012542:Scattering, Radiation; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects
chemical_list: C009495:titanium dioxide; D006046:Gold; D014025:Titanium