Fabrication Of Core-Shell H₃PW₁₂O₄₀@TiO₂ Composite Membrane And Study On Their Photo-electric Properties

Energy crisis and environmental pollution have becom the principal matter to the modern world economy development. The solar enery can be seen as inexhaustible in supply and always available for use, compared with fossil fuel. And it has the special advantages of clean and renewable. The solar cell has become the focous for its ability to convert light into electrocity. It is thought that dye-sensitized nanocrystalline solar cell (DSSC) is a new type of photoelectric chemical solar cell with simple preparation procedure, low cost, stable photo-to-electric performance and friendly environment action, which make it a good alternative of photo-to-electric devices. In addition, the theory and principle about it is significant for semiconductor photoelectronics, nanometer porous material, organic solid-electrolyte and photo-electricchemical, nanometer porous material, and photo-electric chemical. The photoelectric performance of single TiO2 thin film is not satisfied. Polytungstate has the unique structure, although its absorption peak located in the ultraviolet region,but its rear part band may extend to 350~400nm. Moreover, there are many comparabilities between Polytungstate and TiO2 semiconductor. The Polytungstate particle's surface modification and its own characteristics would make TiO2 thin film electrode have the better light absorptive quality, stability and photoelectric performance.In this paper, a novel, simple, fast approach has been developed for the synthesis of anatase TiO2 microcapsules with H3PW12O40 inside by using a polystyrene-bead template. The composite microspheres were well dispersed and the TiO2 was anatase, with H3PW12O40 inside keeping Keggin structure. And the size dimension distribution of the TiO2 is appropriate, with big ratio surface area. The H3PW12O40 enhanced the extinction performance of the TiO2 obviously, expanded its electro-optical corresponding scope. Furthermore, we fabricated fore dye-sensitized solar cells (DSSC) using electrodes of the TiO2@H3PW12O40 composite, dyes of methyl red and Tomato Chinese pear-leaf crabapple, counter-electrodes of ITO and Cu, electrolyte of KI/I2 and Ppy. We examined the photovoltaic performance under simulated sunlight. The result showed that 4 kinds of DSSC had obtained the obvious open-circuit voltage and the short-circuit current, and the open-circuit voltage is quite stable. The TiO2@H3PW12O40 electrode has the good compatibility to liquid electrolyte KI/I2 or solid electrolyte Ppy. Using the liquid electrolyte the short-circuit current of the DSSC is higher than the solid electrolyte obviously, but the open-circuit voltage does not have the obvious influence. It was indicated that the Photo-electric activity of the TiO2@H3PW12O40 composite electrode had well photoelectric performance.