TY - JOUR
T1 - Light-driven oxygen scavenging by titania/polymer nanocomposite films
AU - Xiao, L.
AU - Green, A.N.M.
AU - Haque, S.A.
AU - Mills, A.
AU - Durrant, J.R.
PY - 2004/3/15
Y1 - 2004/3/15
N2 - We demonstrate that UV illumination of nanocrystalline TiO2 films in the presence of excess organic hole scavengers can result in the deoxygenation of a closed environment. The kinetics of deoxygenation are investigated under continuous UV illumination as a function of film preparation and hole scavenger employed. Optimum deoxygenation is observed using methanol as a hole scavenger, although efficient deoxygenation is also observed for a range of different polymer/TiO2 nanocomposite films deposited on glass and plastic substrates. Transient absorption spectroscopy is used to probe the kinetics of the deoxygenation reaction, focusing on the kinetics of the reduction of oxygen by photogenerated TiO2 electrons. Under aerobic conditions, this oxygen reduction reaction is observed to exhibit first order kinetics with a rate constant of 70 s(-1), more than one order of magnitude faster than alternative reaction pathways for the photogenerated electrons. These observations are discussed in terms of the Langmuir-Hinshelwood equation for photocatalytic action.
AB - We demonstrate that UV illumination of nanocrystalline TiO2 films in the presence of excess organic hole scavengers can result in the deoxygenation of a closed environment. The kinetics of deoxygenation are investigated under continuous UV illumination as a function of film preparation and hole scavenger employed. Optimum deoxygenation is observed using methanol as a hole scavenger, although efficient deoxygenation is also observed for a range of different polymer/TiO2 nanocomposite films deposited on glass and plastic substrates. Transient absorption spectroscopy is used to probe the kinetics of the deoxygenation reaction, focusing on the kinetics of the reduction of oxygen by photogenerated TiO2 electrons. Under aerobic conditions, this oxygen reduction reaction is observed to exhibit first order kinetics with a rate constant of 70 s(-1), more than one order of magnitude faster than alternative reaction pathways for the photogenerated electrons. These observations are discussed in terms of the Langmuir-Hinshelwood equation for photocatalytic action.
KW - photocatalysis
KW - nanocrystalline TiO2
KW - polymer
UR - http://dx.doi.org/10.1016/j.nainr.2003.08.010
U2 - 10.1016/j.nainr.2003.08.010
DO - 10.1016/j.nainr.2003.08.010
M3 - Article
SN - 1010-6030
VL - 162
SP - 253
EP - 259
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
IS - 2-3
ER -