Comparative Raman Study of Organic-Free and Surfactant-Capped Rod-Shaped Anatase TiO2 Nanocrystals

Abstract

Excitation of lattice vibrations in nanostructured anatase TiO2 frequently occurs at energy values differing from that found for the corresponding bulk phase. Particularly, investigations have long aimed at establishing a correlation between the low-frequency E-g(1) mode and the mean crystallite size on the basis of phonon-confinement models. Here, we report a detailed Raman study, supported by X-ray diffraction analyses, on anatase TiO2 nanocrystals with rod-shaped morphology and variable geometric parameters, prepared by colloidal wet-chemical routes. By examining the anomalous shifts of the E-g(1) mode in the spectra of surfactant-capped nanorods and in those of corresponding organic-free derivatives (obtained by a suitable thermal oxidative treatment), an insight into the impact of exposed facets and of the coherent crystalline domain size on Raman-active lattice vibrational modes has been gained. Our investigation offers a ground for clarifying the current lack of consensus as to the applicability of phonon-confinement models for drawing information on the size of surface-functionalized TiO2 nanocrystals upon analysis of their Raman features.


Tutti gli autori

  • B. F. Scremin , M. R. Belviso , C. Giannini , D. Altamura , P. D. Cozzoli

Titolo volume/Rivista

SCIENCE OF ADVANCED MATERIALS


Anno di pubblicazione

2014

ISSN

1947-2935

ISBN

Non Disponibile


Numero di citazioni Wos

1

Ultimo Aggiornamento Citazioni

28/04/2018


Numero di citazioni Scopus

1

Ultimo Aggiornamento Citazioni

28/04/2018


Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile