Photocatalytic titanium dioxide composite

In recent years, Titanium Dioxide (TiO2) has gained much more interest for its semiconducting properties for use as photocatalytic material because it rapidly and completely mineralizes organic without harmful byproducts. Based on inspiration from biology, which uses organic structures to guide nucleation and growth of minerals, we demonstrate controlled synthesis of TiO2 using a hydrophilic synthetic polymer. In the absence of the polymer, TiO2 completely transforms to rutile by 72 hours, however with the addition of the polymer larger anatase crystallites are observed due to the reduced number of nuclei formed. Under these conditions, complete transformation to rutile was not observed due to diffusion-limited growth of TiO2 as well as the presence of an organic coating on the crystallites. However nanoparticles are difficult to recover from effluent streams. We use the polymer to develop bulk composite TiO2-organic structures which can be fabricated and tailored as a stand alone photocatalysts, eliminating the need for nanoparticle recovery systems, thereby reducing processing costs.