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Titanium dioxide nanotube and enzyme-enhanced photo-bio-fuel cell
|Adrianna Złoczewska 2, Robert P. Lynch 1,2, Martin Jönsson-Niedziółka 2, Marcin Opallo 2|
1. Department of Physics, and Materials and Surface science Institute, University of Limerick, Limerick xxxx, Ireland
There is an ongoing need to obtain a source of renewable energy harvested, for example, directly from the Sun (1) or a source of energy that is easily accessible and transportable such as oxygen and methanol or oxygen and glucose.
Enzyme modified electrodes have attracted much attention due to their application as catalytic electrodes in bio-fuel cells. (2) Recently we investigated single-walled carbon nanotubes functionalised with 1-pyrenesulfonic acid (PSA) as a means for improving the direct electron transfer to the enzyme bilirubin oxidase. (3) The nanotubes were co-immobilised with bilirubin oxidase in a silicate matrix on tin-doped indium oxide. These electrodes can be used for the bioelectrocatalytic reduction of dioxygen to water from solution.
TiO2 nanotubes have developed great interest due to their ability to form electrodes with increased effective surface area. In addition, our previous work has shown that the order and smoothness of these vertically aligned TiO2 nanotubes can be increased resulting in an increase in the electron diffusion length along the tubes and a corresponding increase in conductivity and light to electricity conversion efficiency. (4) Nanostructured semiconducting photo-anodes have been shown by Moore et al. to work in combination with enzyme catalysed oxidation of biofuels. (5) In their work visible light incident on these modified electrodes was shown to result in the photo excitation of a porphyrin dye and the separation of charge. The dye was quenched by β-nicotinamide adenine dinucleotide (NADH) present in the electrolyte solution transforming it ultimately to NAD+. The catalytic oxidation of glucose within the cell in the presence of glucose dehydrogenase (GDH) replenished the supplies of NADH from the oxidised form of this mediator, NAD+, allowing the photo-anode reactions to continue as long as glucose was present.(6)
In this poster we combine two processes – the oxidation reactions driven by a TiO2-modified photo-anode and dioxygen reduction by enzyme at a CNT-modified cathode – allowing for the formation of novel photo-electrochemical bio-fuel cells. The resulting cells produce a potential difference and a flow of current between the terminals dependent on the intensity of the incident light. Several variations of the cell were constructed so as to investigate the reactions occurring in the cell and so as to determine the dependence of cell performance on cell structure, electrode type and dye type. In addition comparison is made between our results and the existing technology and work published by other groups.
(1) B. O'Regan, M. Grätzel, Nature 1991, 353 (6346), 737
(2) I. Willner, Science 2002, 298, 2407
(3) M. Jönsson-Niedziolka, A. Kaminska, M. Opallo, Electrochimica Acta 2010, 55, 8744
(4) R.P. Lynch, A. Ghicov and P. Schmuki, J. Electrochem. Soc. 2010, 157 (3), G76
(5) A. Brune et al., Langmuir 2004, 20, 8366
(6) M. Hambourger et al., Photochem. Photobiol. Sci., 2007, 6, 431
Presentation: Poster at SMCBS'2011 International Workshop, by Adrianna Złoczewska
See On-line Journal of SMCBS'2011 International Workshop
Submitted: 2011-09-07 23:27 Revised: 2011-09-07 23:27