TY - JOUR
T1 - Electrochemical Enhancement of Photocatalytic Disinfection on Aligned TiO2 and Nitrogen Doped TiO2 Nanotubes
AU - Pablos, Cristina
AU - Marugán, Javier
AU - van Grieken, Rafael
AU - Dunlop, PSM
AU - Hamilton, Jeremy
AU - Dionysiou, Dionysios
AU - Byrne, JA
PY - 2017/4/28
Y1 - 2017/4/28
N2 - TiO2 photocatalysis is considered as an alternative to conventional disinfection processesfor the inactivation of waterborne microorganisms. The efficiency of photocatalysis is limitedby charge carrier recombination rates. When the photocatalyst is immobilized on an electricallyconducting support, one may assist charge separation by the application of an external electrical bias. The aim of this work was to study electrochemically assisted photocatalysis with nitrogen doped titania photoanodes under visible and UV-visible irradiation for the inactivation of Escherichia coli. Aligned TiO2 nanotubes were synthesized (TiO2-NT) by anodizing Ti foil. Nanoparticulate titania films were made on Ti foil by electrophoretic coating (P25 TiO2). N-doped titania nanotubes and N,F co-doped titania films were also prepared with the aim of extending the active spectrum into the visible. Electrochemically assisted photocatalysis gave higher disinfection efficiency in comparison to photocatalysis (electrode at open circuit) for all materials tested. It is proposed that electrostatic attraction of negatively charged bacteria to the positively biased photoanodes leads to the enhancement observed. The N-doped TiO2 nanotube electrode gave the most efficient electrochemically assisted photocatalytic inactivation of bacteria under UV-Vis irradiation but no inactivation of bacteria was observed under visible only irradiation. The visible light photocurrent was only a fraction (2%) of the UV response.
AB - TiO2 photocatalysis is considered as an alternative to conventional disinfection processesfor the inactivation of waterborne microorganisms. The efficiency of photocatalysis is limitedby charge carrier recombination rates. When the photocatalyst is immobilized on an electricallyconducting support, one may assist charge separation by the application of an external electrical bias. The aim of this work was to study electrochemically assisted photocatalysis with nitrogen doped titania photoanodes under visible and UV-visible irradiation for the inactivation of Escherichia coli. Aligned TiO2 nanotubes were synthesized (TiO2-NT) by anodizing Ti foil. Nanoparticulate titania films were made on Ti foil by electrophoretic coating (P25 TiO2). N-doped titania nanotubes and N,F co-doped titania films were also prepared with the aim of extending the active spectrum into the visible. Electrochemically assisted photocatalysis gave higher disinfection efficiency in comparison to photocatalysis (electrode at open circuit) for all materials tested. It is proposed that electrostatic attraction of negatively charged bacteria to the positively biased photoanodes leads to the enhancement observed. The N-doped TiO2 nanotube electrode gave the most efficient electrochemically assisted photocatalytic inactivation of bacteria under UV-Vis irradiation but no inactivation of bacteria was observed under visible only irradiation. The visible light photocurrent was only a fraction (2%) of the UV response.
KW - titania nanotubes
KW - nitrogen-doped nanotubes
KW - photoelectrocatalysis
KW - E. coli
KW - visible light
UR - https://pure.ulster.ac.uk/en/publications/electrochemical-enhancement-of-photocatalytic-disinfection-on-ali-3
U2 - 10.3390/molecules22050704
DO - 10.3390/molecules22050704
M3 - Article
C2 - 28452966
SN - 1420-3049
VL - 22
JO - Molecules
JF - Molecules
IS - 5
ER -