TiO2 decorated CNTs nanocomposite for efficient photocatalytic degradation of methylene blue

Abstract

The dyes and pollutants elimination from wastewater is a crucial challenge footstep from the degradation of dyes along with specific types of photocatalysts. In the present work, different photocatalysts such as titanium dioxides (TiO2), carbon nanotubes (CNTs) and titania-cabon nanotubes (TiO2/CNTs) were synthesized by hydrothermal method. Methylene blue (MB) degradation was observed in the presence of TiO2/CNTs nanocomposite and it was observed that both dye adsorption and degradation took place, simultaneously. However, gradually a deep decolorization was observed with each 20 min intervals of time till aqous solution become transparent. Photocatalysts were characterized by various characterization techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and ultraviolet-visible spectroscopy (UV–vis). Furthermore, MB was degraded rapidly within 180 min of illumination of visible light using TiO2, CNTs and TiO2/CNTs nanocomposite. More interestingly, TiO2/CNTs nanocomposite (0.2 g) showed a rapid increase of more than 85 % in degradation with optimum reaction conditions than pure TiO2, and CNTs. The TiO2/CNTs showed enhanced cyclic stability through 5 consecutive numbers of cycles. Kinetic study revealed that synthesized nanocomposite followed the zero-order kinetics.