fulltext.study @t Gmail

A surface science approach to TiO2 P25 photocatalysis: An in situ FTIR study of phenol photodegradation at controlled water coverages from sub-monolayer to multilayer

Paper ID Volume ID Publish Year Pages File Format Full-Text
44979 46390 2016 7 PDF Available
Title
A surface science approach to TiO2 P25 photocatalysis: An in situ FTIR study of phenol photodegradation at controlled water coverages from sub-monolayer to multilayer
Abstract

•New transmission FTIR set-up to investigate photocatalytic reactions under in situ UV–vis illumination and in controlled atmosphere.•This approach helps to close the gap between conventional surface science studies and investigations carried out in solution.•Detailed study of the processes occurring in the adsorbed layer during phenol photodegradation.•Key role of co-adsorbed water highlighted by varying the water coverages from sub-monolayer to multilayer.

The photodegradation of phenol on TiO2 P25 has been investigated by a transmission FTIR set-up allowing to monitor the processes occurring at the oxide surface during photocatalytic reactions under in situ UV–vis irradiation and in controlled atmosphere, after sending well-defined doses of adsorbates. This approach helps to close the gap between conventional surface science studies and investigations carried out in solution. The study of the mechanism of adsorption demonstrates that phenol dosed from the gas phase on the dehydroxylated surface readily dissociates to form OH groups and adsorbed phenolate species. After completion of the monolayer, further phenol is adsorbed in molecular form to build a multilayer. The state of adsorbed phenol in presence of increasing amounts of co-adsorbed water has also been accurately monitored. During UV–vis irradiation the main phenol signals progressively decrease, while new bands appear, ascribed to the formation of adsorbed oxalates and carbonates. Also the presence of small quantities of catechol and hydroquinone cannot be excluded. The pseudo-first order rate constant for the phenol photodegradation results to be strongly dependent on the surface hydration conditions and increases of one order of magnitude moving from a nearly dehydrated surface to a surface with a multilayer of liquid-like adsorbed water (i.e. a condition more representative of the processes occurring at the oxide surface when TiO2 is immersed in solution like in most applications).

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Phenol photodegradation; TiO2 P25; Adsorbed water; FTIR spectroscopy; Degradation kinetics
First Page Preview
A surface science approach to TiO2 P25 photocatalysis: An in situ FTIR study of phenol photodegradation at controlled water coverages from sub-monolayer to multilayer
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis B: Environmental - Volume 196, 5 November 2016, Pages 135–141
Authors
, , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us