Photoactive layer-by-layer films of cellulose phosphate and titanium dioxide containing phosphotungstic acid

A versatile layer-by-layer (LbL) procedure for the preparation of highly dispersed, adherent and porous multilayer films of TiO 2 nanoparticles (NPs) and phosphotungstic acid (HPW) on a variety of substrates at room temperature was developed based on the use of cellulose phosphate (CP) as an efficie...

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Detalles Bibliográficos
Autores principales: Ullah, S., Acuña, J.J.S., Pasa, A.A., Bilmes, S.A., Vela, M.E., Benitez, G., Rodrigues-Filho, U.P.
Formato: JOUR
Materias:
Cellulose phosphate
Layer-by-Layer
Photocatalysis
Photochromism
Titania Phosphotungstic acid
Absorption spectroscopy
Aromatic compounds
Boron carbide
Cellulose
Cellulose films
Crystal atomic structure
Crystalline materials
Dyes
Film preparation
Fourier transform infrared spectroscopy
Interfaces (materials)
Irradiation
Nanocomposite films
Oxide minerals
Polyelectrolytes
Titanium dioxide
X ray photoelectron spectroscopy
Adsorption ability
Bacterial cellulose
Environmentally safe
Interfacial electron transfer
Layer by layer
Phosphotungstic acid
TiO2 nano-particles
Multilayer films
Aromatic Compounds
Boron Compounds
Catalysts
Cellulose Derivatives
Fourier Analysis
Interfaces
Oxides
Titanium Dioxide
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_01694332_v277_n_p111_Ullah
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:A versatile layer-by-layer (LbL) procedure for the preparation of highly dispersed, adherent and porous multilayer films of TiO 2 nanoparticles (NPs) and phosphotungstic acid (HPW) on a variety of substrates at room temperature was developed based on the use of cellulose phosphate (CP) as an efficient and non-conventional polyelectrolyte. UV/vis absorption spectroscopy confirmed the linear and regular growth of the films with the number of immersion cycles and a strong adsorption ability of CP towards TiO 2 NPs. FTIR spectroscopy showed that HPW binds to the surface of TiO 2 through the oxygen atom at the corner of the Keggin structure. XPS results showed that the interaction between TiO 2 and CP is through Ti-O-P linkage. A model is proposed for the TiO 2 -HPW interaction based on XPS and FTIR results. FEG/SEM study of the surface morphology revealed a porous film structure with a homogenous distribution of the TiO 2 NPs induced by CP. HRTEM studies showed that the resulting composite films consist of crystalline anatase and rutile phases and poly-nano-crystalline HPW with a semi-crystalline TiO 2 -HPW interface. These CP/TiO 2 and CP/TiO 2 /HPW LbL films showed good photoactivity against both saturated and unsaturated species, for instance, stearic acid (SA), crystal violet (CV) and methylene blue (MB) under UV irradiation. The CP/HPW films formed on bacterial cellulose (BC) showed good photochromic response which is enhanced in presence of TiO 2 due to an interfacial electron transfer from TiO 2 to HPW. This simple and environmentally safe method can be used to form coatings on a variety of surfaces with photoactive TiO 2 and TiO 2 /HPW films. © 2013 Elsevier B.V. All rights reserved.

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