Surface Modification of TiO₂ nanoparticles using Conducting Polymer Coating: Spectroscopic, Structural, Morphological Characterization and Interaction with Dye Molecules

In the present research, the surface of titanium dioxide nanoparticles was modified using a conducting polymer coating in the presence of an oxidizing agent. The structure and morphology of as-modified polypyrrole-coated titanium dioxide nanoparticles were investigated by X-ray diffraction and Transmission electron microscopy techniques. The nitrogen adsorption-desorption performance of as-modified polypyrrole-coated titanium dioxide nanoparticles were also investigated to revealed its details of specific surface area, structural properties and pore geometries. The polypyrrole coated titanium dioxide nanoparticles were utilized for adsorption of hazardous anionic dye (Congo red) from aqueous solution. The adsorption of Congo red dye onto polypyrrole-coated titanium dioxide nano-adsorbent was confirmed by advanced instrumental techniques such as Fourier transform infrared spectroscopy, Field emission scanning electron microscopy, Energy dispersive x-ray spectroscopy and Elemental mapping analysis. The adsorption performance of polypyrrole-coated titanium dioxide nano-adsorbent was evaluated by batch experimental technique. The effects of different parameters such as pH, contact time, and dose on the adsorption tests were also determined. The highest adsorption of Congo red dye (98.75%) was achieved at pH ˜3 using 50 mg of polypyrrole-coated titanium dioxide nano-adsorbent. The reusability of polypyrrole-coated titanium dioxide nano-adsorbent was also evaluated by several adsorptions-desorption cycles. The reusability result demonstrated excellent adsorption potential of polypyrrole-coated titanium dioxide nano-adsorbent for water-treatment application.