Photocatalytic Degradation of Dyes in Wastewater using TiO2/CNT Composite

Abstract

Currently, the most important issue is the disposal of harmful organic mixes and compounds from wastewater which is not only dangerous for human life but also for plant and aquatic life. Among them, most of the pollutants and contaminants are dyes, for example, methyl blue (MB) released from various textile industries causing unwanted taste, smell and color in water. Herein, an attempt to enhance the photo response of TiO2 towards visible irradiation and inhibit recombination of energized e- /h+ pairs during photocatalytic reaction, ternary NS-TiO2/CNTs nanocomposite was prepared using sol gel methodology. The physical and chemical properties of photocatalysts were examined by X-ray Diffraction (XRD) and Fourier-Transform Infrared Spectroscopy (FTIR). Photocatalytic activity was investigated for discoloration of MB under artificial light. For comparative purpose, reference catalysts i.e. TiO2, N-doped TiO2, TiO2/CNT and NS co-doped TiO2 were also prepared, characterized and their photocatalytic degradation rates were likewise compared and assessed. NS-TiO2/CNTs nanocomposite shows (3 times) highest photocatalytic activities than binary composites (N-TiO2, TiO2/CNTs, NS-TiO2) and (4 times) higher than bare TiO2. The photo degradation results showed that incorporation of dopants and CNTs in TiO2 lattice facilitated effective separation of charge carriers in N,STiO2/CNTs as carbon nanotubes trap the electrons that further react with hydroxyl radicals (OH. ) to decompose dyes. This study emphasis the importance of ternary nanocomposite (NS-TiO2/CNTs) as highly-efficient and visible-active photo catalyst for the elimination of dyes.