“The production of titanium dioxide (TiO2) represents a very large market and should top $2.3 billion by 2012. Nearly 95% of the TiO2 production is supplied into the pigment industry for a volume of 4.5 million tons. Indeed, TiO2 is the most widely used white pigment mainly in the paint, coating, plastic, paper, food, pharmaceutical or cosmetic industries. Besides, as a photocatalyst, TiO2 is used for its sterilizing, deodorizing and antifouling properties. TiO2 is also the choice material for antifogging coatings and self-cleaning windows because of its superhydrophilicity. In addition, TiO2 is a semiconductor and, among other applications, is used as oxygen sensor in the lambda probes for car engines. Even though the main applications of TiO2 are in mature sectors, the production of TiO2 in the form of nanoparticles, thus having a high surface-to-volume ratio, is beneficial to the development of high-tech applications which have more recently emerged, such as water splitting and dye-sensitized solar cells (DSSCs). The total world demand for nano-TiO2 represents less than 0,6% of TiO2 pigmentary demand, but market revenues for nano-TiO2 are expected to rise from $360 million in 2009 to about $1.5 billion by 2017. Research on DSSCs based on nanocrystalline TiO2 has been extensively pursued, and the number of papers published in this area has grown exponentially over the last ten years. However, at present, commercial devices are produced in limited quantities, small sizes and address niche markets. Research efforts have largely focused on the optimization of the dye, but recently the TiO2 nanocrystalline electrode itself has attracted more attention. Yet, even if it has been determined that the binding of the dye to the TiO2 surface plays an important role in the electron injection efficiency and the cell stability, the surface chemistry of nanocrystalline TiO2 has seldom been considered as a key parameter to be specifically controlled prior to dye attachment and device fabrication. In addition to a brief overview of the DSSCs production and market, this paper will show how some results of our fundamental investigation on the surface reactions leading to the dye attachment to TiO2 can be integrated in the device fabrication process for optimized stability of DSSCs.”
This talk has been presented at MRS Spring Meeting 2011.