Synthesis Of Frustule/Titania Composite And Its Application In Solar Cell Device

Owing to the excellent diverse three-dimensional (3D) regular silica structure on thenanometer to micrometer scale of the diatom frustules, some special and characteristic propertieslike high specific surface area, high toughness, and high transmit rate, etc. are endowed, whichput it in the spotlight in the field of advanced materials. At the meantime, as fossil energyreserves decrease ceaselessly, the solar energy as a typical new energy is widely noted. Recently,some great developments in the fields of solar cell are achieved depending on the tireless effortsof scientists. Specially, the dye-sensitized solar cell, a new element, attracts tremendous attentionbecause of its simple construction, easy making process and low cost. In this paper, theCoscinodiscus sp. frustule is selected as the template in sol-gel method with acetylacetone (acac)thanks to its comparatively large scale and easiness in separation and observation. The frustule/titania composites and frustule/N-titania composite have been synthesized by a facile way, andthen, the biomorphic titania in agaric shape has been achieved. The three composites arecharacterized by scanning electron microscope (SEM), electron energy spectrum (EDS), X-raydiffraction (XRD), infrared spectroscopy (IR) and solid fluorimetry, thus, the possible reactionmechanism in the process is expounded. Furthermore, the different dye-sensitized solar cellswith different materials are contrastively analyzed.The main results are as follows:(1) The Coscinodiscus sp. frustule possesses intricate and ornate multistage3D architecture;the Si-O-Si and Si-OH groups dominate on the frustule surface, and the activity of Si-OH groupwill dissolve at the high temperature over550℃; the photoluminescence wavelength is observedat311nm.(2) The frustule/titania, frustule/N-titania and biomorphic titania nano-materials areobtained by using the template in sol-gel method with acac, during the process, the optimummole ratio of3:1between Si and Ti are achieved naturally, and the reaction mechanism is expounded logically. The three synthesized photoelectric materials (frustule/titania, frustule/N-titania and biomorphic titania in agaric shape) can be serve as light amplifiers benefiting fromits inverse-opal structure. Subsequently, the surface of frustule/N-titania is slicker than frustule/titania’s with the help of SEM; the results of SEM and XRD showed that titania grain size ofbiomorphic titania has decreased, and obviously, the corrugated agaric shape can increasespecific surface area of the nano-material; by the solid fluorimetry the photoluminescencewavelength of frustule/titania composite is observed at399nm.(3) The dye-sensitized solar cell based on frustule/titania composite has been manufacturedwell, and the largest energy conversion rate reaches3.12％, which increases50％better than thedye-sensitized solar cells with same film area. Consequently, the rank of energy conversion rateof different cells in this order: cell based on frustule/titania> cell based on frustule>conventional cell.