title: High Visible Photoelectrochemical Activity of Ag Nanoparticle-Sandwiched CdS/Ag/ZnO Nanorods.
abstract: We report on the sensitizing of CdS-coated ZnO (CdS/ZnO) nanorods (NRs) by Ag nanoparticles (NPs) embedded between the CdS coating and the ZnO nanorod and the improved optical and photoelectrochemical properties of the Ag NP-sandwiched nanostructure CdS/Ag/ZnO NRs. The CdS/Ag/ZnO NRs were fabricated by growing Ag NPs on hydrothermally grown ZnO NRs and subsequently depositing CdS coatings followed by subsequent N2annealing. The structure of the fabricated CdS/Ag/ZnO NRs was characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Raman backscattering, revealing that the ZnO NRs and the CdS coatings are both structured with hexagonal wurtzite and the Ag NPs contact well with ZnO and CdS. Optical properties were evaluated by measuring optical absorption and photoluminescence, showing that the Ag NPs behave well as sensitizers for optical property improvement and the CdS/Ag/ZnO NRs exhibit better photoresponse in a wide spectral region than CdS/ZnO because of plasmon-enhanced absorption due to the embedment of Ag NPs. The Ag NPs also serve as electron relays from CdS to ZnO, facilitating electron transfer from the CdS coatings to the ZnO NRs. The excellent photoresponse and efficient electron transfer make the CdS/Ag/ZnO NRs highly photoelectrochemically active. The CdS/Ag/ZnO NRs fabricated on indium-tin oxide present much better photoelectrochemical performance as photoanodes working in the visible region than CdS/ZnO NRs without Ag NPs. Under visible illumination, a maximum optical-to-chemical conversion efficiency of 3.13% is obtained for CdS/Ag/ZnO NR photoanodes against 1.35% for CdS/ZnO NR photoanodes.
authors.affiliation: Department of Optical Science and Engineering, and Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University , Shanghai 200433, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Optical Science and Engineering, and Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University , Shanghai 200433, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Optical Science and Engineering, and Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University , Shanghai 200433, China.
authors.forename: Wu
authors.initials: W
authors.lastname: Zhang
authors.affiliation: School of Materials Engineering, Shanghai University of Engineering Science , Shanghai 201620, China.
authors.forename: Mingxuan
authors.initials: M
authors.lastname: Sun
authors.affiliation: Department of Optical Science and Engineering, and Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University , Shanghai 200433, China.
authors.forename: Lequn
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Optical Science and Engineering, and Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University , Shanghai 200433, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Xu
authors.affiliation: Department of Optical Science and Engineering, and Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University , Shanghai 200433, China.
authors.forename: Jiada
authors.identifier: http://orcid.org/0000-0003-4022-4300
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Optical Science and Engineering, and Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University , Shanghai 200433, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
keywords: Ag nanoparticle; CdS-coated ZnO nanorod; localized surface plasmon resonance; photoelectrochemical property; photoresponse; sandwiched nanostructure