Hybrid Photoelectrochemical Biofuel Cell With Enzyme-cdse-tio₂ Architecture

Recently, dye-sensitized solar cells (DSSCs) are extensively studied due to their special features such as low cost, surrounding friendly and high power conversion efficiency in recent year. One of very interesting of DSSCs is quantum dots (QDs) -sensitized solar cells, which have drawn a lot of attention during the past few years because semiconductor quantum dots feature long-term stability, sizable adsorption from UV to the infrared, a tunable band structure and even charge carrier multiplication.In this thesis, using the layer-by-layer (LBL) assembly, we assembled the dispersed CdSe@CdS core-shell QDs over mesoporous TiO₂ matrix. Two types of photoanodes were obtained by choosing different polyelectrolyte: Type 1 films ITO/TiO₂/(CdSe@CdS/PAH)n and Type 2 films ITO/TiO₂/(CdSe@CdS/ [Co(Phen)₃]²⁺-PEI)n. The multilayer build-up, monitored by UV-vis spectroscopy shows an increase in the film absorbance with the number of adsorbed CdSe@CdS layers. The photoluminescence (PL) and photoelectrochemical properties of the multilayers were investigated. The photoelectrochemical measurements showed that the photocurrent is directly proportional to the quantity of attached QDs. Moreover, the performances of Type 2 electrodes are much higher than that of Type 1 electrodes.Further, the photoanode of hybrid photoelectrochemical biofuel cell was fabricated by depositing three bilayers of GOD/[Co(Phen)₃]²⁺-PEI on the Type 2 multilayer films. The photoanode can remarkably generate the photocurrent under the illumination with a power of 150 W. Moreover, upon the addition of glucose, the photocurrent was remarkably enhanced. The photocurrent increases with increasing concentrations of glucose in PBS (20 mM, pH=7.4) electrolyte and reached at maximum at a glucose concentration of 8 mM.