Self-standing Hybrid Nanofibers of TiO2 and TiO2/Hydroxyapatite: Application in Photocatalytic and Photovoltatic Systems

A Hybrid fibers of Hydroxyapatite TiO$_{2}$, HAp/TiO$_{2}$ with modified photocatalytic properties were synthesized using a template method. Liquid phase deposition (LPD) technique was employed to grow TiO$_{2}$ layers on cellulose fibers, followed by deposition of HAp from a pseudo body solution, and finally heat removing the cellulose template. The resulting material has a fibrous structure, mimicking the cellulose fibers shape, and have a typical surface area of 114 m$^{2}$/g, compared to 74 m$^{2}$/g for pure TiO$_{2}$ fibers. Adsorption and photocatalytic degradation tests showed that addition of HAp to TiO$_{2}$ fibers increased the adsorptive from 17{\%} to 35{\%}. Nano particulated TiO$_{2}$ fibers as one-dimensional long structures were introduced into TiO$_{2}$ P25 nano particle films using co-electrophoretic deposition. This resulted in less porosity and higher roughness factor of the films that provided more favorable conditions for electron transport. The films used as the photoanode of a dye solar cell (DSC) produced 65{\%} higher photovoltaic efficiency. TiO$_{2}$ fibers can be excellent binders in single-step, organic-free electrophoretic deposition of TiO$_{2}$ for DSC photoanode.