修飾PtRu奈米顆粒之石墨烯應用於染料敏化太陽能電池的研製

Dye-sensitized solar cell has the advantages of simple fabrication process, low cost, low pollution, and can be assembled under the general environment. At present, its power conversion efficiency has exceeded 12%, but it still has considerable development potential. DSSC is built up with a working electrode and a counter electrode. This project will use graphene flakes decorated with Pt and PtRu nano-particles to replace the Pt film of counter electrode. Pt and PtRu nanoparticles were decorated on the surface of graphene flakes and carbon nanotubes by a chemical plating technique. The TiO2 slurry of working electrode also will be added with appropriate amount of graphene flakes, which can increase the transmission path and efficiency of photoelectrons through TiO2 slurry as dye irradiated from light, so that photoelectrons can be successfully transmitted to the FTO substrate and do work on the external circuit, and avoid photoelectrons produce recombined phenomenon with dyes or electrolytes. It is expected that the above-mentioned two ways can improve the power conversion efficiency of current DSSC. The working items of this project are as followed: 1. Technology development of Nanocarbon decorated PtRu nanoparticles: H2PtCl6 ‧ 6H2O and RuCl3 ‧ X H2O are used as precursors, mixed with reducing agent C2H4(OH)2, and buffer solution CH3COOH-NaOH for chemical plating process. The nano-metal particles with particle size less than 10 nm will be decorated on the surface of nanocarbon. The effect of chemical plating on the kinds of graphene flakes and nano-metal particles will be discussed. 2. Fabrication of counter electrodes with nanocarbon/PtRu coating: Nano-carbon material/Pt or PtRu particles catalyst layer will be coated on the surface of FTO substrate. There are five materials assemble including M-GNS/CNT/Pt and PtRu, C-GNS/CNT/Pt and PtRu, and conventional Pt film. The resistance and average conductivity of these five counter electrodes will be measured respectively; the electrode catalytic reaction test will also be done using cyclic voltammetry method. 3. Fabrication of working electrodes with TiO2/graphene/dye coating: The TiO2 slurry is coated onto the FTO surface and sintered at 450 °C for 30 minutes and soaked in the dye to complete the preparation of working electrodes. The TiO2 slurry will also be doped with an appropriate amount of nano-carbon, such as M-GNS and C-GNS/carbon nanotubes, to increase the transmission path and efficiency of photoelectrons to the FTO substrate. M-GNS/CNT/TiO2, C-GNS/CNT/TiO2 and pure TiO2 slurry will be evaluated whether the nano-carbon material is possible to promote the transmittance, conductivity and specific surface area of working electrode. 4. Assembly and performance measurement of DSSC: If the working electrode and counter electrode are completed, the liquid or colloidal electrolyte (I-/I3-) is injected and sandwiched with these two electrodes, and then a DSSC device is completed. Finally, the DSSCs will evaluate their photoelectric power conversion efficiency. The I-V curve of DSSC will be obtained under the AM 1.5G simulated sunlight irradiation and converted as the power conversion efficiency. It is hoped that such a novel DSSC can break the current bottleneck of conversion efficiency 12%.