Self-Assembled TiO₂ Nanospheres By Using a Biopolymer as a Template and Its Optoelectronic Application

Self-assembled TiO₂ nanoparticulate materials with well-defined spherical morphologies were synthesized by using a biopolymer sodium alginate as a template under different synthesis conditions. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) techniques were used to characterize the TiO₂ nanoparticles. N₂ sorption analysis revealed the moderately good surface area (124.0 m² g^–1) and pore volume (0.44 cm³ g^–1) of these TiO₂ nanoparticles. The biopolymer templating pathway leads to good-quality self-assembled TiO₂ nanoparticles with dimensions of ca. 10–12 nm within the synthesis temperature range of 0–60 °C. These porous TiO₂ nanomaterials showed high photogenerated current in the presence of a dye (Rose Bengal), used as a sensitizer for several photo on/off cycles.