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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

In situ growth of Ag nanoparticles on alpha-Ag2WO4 under electron irradiation: probing the physical principles

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San-Miguel, Miguel A. [1] ; da Silva, Edison Z. [2] ; Zannetti, Sonia M. [3] ; Cilense, Mario [3] ; Fabbro, Maria T. [4] ; Gracia, Lourdes [5] ; Andres, Juan [5] ; Longo, Elson [6]
Total Authors: 8
[1] Univ Estadual Campinas, State Univ Campinas, Inst Chem, BR-13083970 Campinas, SP - Brazil
[2] Univ Estadual Campinas, State Univ Campinas, Inst Phys Gleb Wataghin, BR-13083970 Campinas, SP - Brazil
[3] UNESP Univ Estadual Paulista, Inst Chem, BR-14800900 Araraquara, SP - Brazil
[4] Fed Univ Sao Carlos UFSCar, Dept Chem, BR-13565905 Sao Carlos, SP - Brazil
[5] Univ Jaume 1, Dept Quim Fis & Analit, E-12071 Castellon de La Plana - Spain
[6] Univ Estadual Paulista, CDMF UNESP, POB 355, BR-14801907 Araraquara, SP - Brazil
Total Affiliations: 6
Document type: Journal article
Source: Nanotechnology; v. 27, n. 22 JUN 3 2016.
Web of Science Citations: 15

Exploiting the plasmonic behavior of Ag nanoparticles grown on alpha-Ag2WO4 is a widely employed strategy to produce efficient photocatalysts, ozone sensors, and bactericides. However, a description of the atomic and electronic structure of the semiconductor sites irradiated by electrons is still not available. Such a description is of great importance to understand the mechanisms underlying these physical processes and to improve the design of silver nanoparticles to enhance their activities. Motivated by this, we studied the growth of silver nanoparticles to investigate this novel class of phenomena using both transmission electron microscopy and field emission scanning electron microscopy. A theoretical framework based on density functional theory calculations (DFT), together with experimental analysis and measurements, were developed to examine the changes in the local geometrical and electronic structure of the materials. The physical principles for the formation of Ag nanoparticles on alpha-Ag2WO4 by electron beam irradiation are described. Quantum mechanical calculations based on DFT show that the (001) of alpha-Ag2WO4 displays Ag atoms with different coordination numbers. Some of them are able to diffuse out of the surface with a very low energy barrier (less than 0.1 eV), thus, initiating the growth of metallic Ag nanostructures and leaving Ag vacancies in the bulk material. These processes increase the structural disorder of alpha-Ag2WO4 as well as its electrical resistance as observed in the experimental measurements. (AU)

FAPESP's process: 10/16970-0 - Computational modeling of condensed matter: a multiscale approach
Grantee:Alex Antonelli
Support type: Research Projects - Thematic Grants
FAPESP's process: 08/57872-1 - National Institute for Materials Science in Nanotechnology
Grantee:Elson Longo da Silva
Support type: Research Projects - Thematic Grants
FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
Grantee:Elson Longo da Silva
Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC
FAPESP's process: 12/14468-1 - Development and theoretical-experimental interpretation of BaZrO3@ZnS system
Grantee:Mateus Meneghetti Ferrer
Support type: Scholarships in Brazil - Doctorate