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Copper-aided photosterilization of microbial cells on TiO2 film under irradiation from a white light fluorescent lamp

Paper ID Volume ID Publish Year Pages File Format Full-Text
5010 269 2006 6 PDF Available
Title
Copper-aided photosterilization of microbial cells on TiO2 film under irradiation from a white light fluorescent lamp
Abstract

The copper-aided photosterilization of Escherichia coli was examined on TiO2 thin films under a lighting condition with less UV rays from a white light fluorescent lamp. It was found that the coexistence of Cu2+ and H2O2 in liquid phase exerted the synergistic effect on killing E. coli cells though these chemical species were individually at nontoxic levels to the cells (less than 10 mmol/m3). At an incident light intensity of I0 = 28 W/m2, the addition of Cu2+ (10 mmol/m3) to liquid phase on TiO2 film gave the apparent deactivation rate constant of k′ = 12 × 10−2 min−1, the value of which was about 5 times as large as that on TiO2 film in the absence of Cu2+. This result suggested that in the liquid phase, Cu2+ was reduced to Cu+ by receiving electron from photo-excited TiO2, and then Cu+ reacted with photocatalysis-derived H2O2 to produce OH via Fenton-type reaction. The deactivation tests were also examined using a modified film preparation made from copper-incorporated TiO2. On this film, the k′ value was 23 × 10−2 min−1 at I0 = 28 W/m2, which was respectively about two and nine times as large as those on the original TiO2 film with and without Cu2+ addition (10 mmol/m3). The enhancement of biocidal activity on the modified TiO2 film was considered to arise from promoted OH formation by the aid of copper component anchored in TiO2 solid phase.

Keywords
Titanium dioxide; Photocatalytic sterilization; Escherichia coli; Copper-aided reaction; Reactive oxygen species
First Page Preview
Copper-aided photosterilization of microbial cells on TiO2 film under irradiation from a white light fluorescent lamp
Publisher
Database: Elsevier - ScienceDirect
Journal: Biochemical Engineering Journal - Volume 30, Issue 2, 1 June 2006, Pages 199–204
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering