Preparation and Performance of TiO2-ZnO/CNT Hetero-Nanostructures Applied to Photodegradation of Organic Dye

Abstract

Water pollution by organic compounds is one of the major challenges faced by industries that use dyeing processes. Thus, some methods were developed for degrading dyes in wastewaters, including heterogeneous photocatalysis by semiconductor oxides. However, these oxides have limited photocatalytic activity due to the fast recombination of photogenerated electron-hole pairs. The aim of this study is the use of a carbon nanotube (CNT) and TiO 2 -ZnO oxide junction from modified sol-gel method to promote the degradation of organic dye through the photocatalytic activity of these nanocomposites. TiO 2 -ZnO/CNT nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM) and photocatalytic decomposition of organic dyes. The results of photocatalysis show up to 60% the efficiency of the samples in the removal of dye.

MWCNTs attached neodymium doped-ZnO photocatalysts for efficient removal of dyes from wastewater

“…For example, neodymium (Nd) doping of TiO 2 has been recognised as a feasible technique for augmenting its photocatalytic activity where the Nd acts as an electron sink and thus prevented the rate at which the generated electrons and holes recombine. It was also noted to decrease the band gap of TiO 2 leading to an improvement in its organic pollutant removal efficiency in the visible region of the solar spectrum [14]. Some semiconductors photocatalysts have also been modified with multiwalled carbon nanotubes (MWCNTs) so as to establish the probable application of MWCNTsbased nanocomposites in organic dyes removal in water [15][16][17].…”

The Visible-Light-Driven Activity of Biochar-Doped TiO2 Photocatalysts in β-Blockers Removal from Water

“…The traditionally used TiO 2 , besides high activity, stability, and chemical indifference, requires highly energetic UV light [ 17 ]. The approach to increase the activity of TiO 2 towards visible light considers doping with metals [ 18 ], non-metals [ 19 ], formation of heterojunctions [ 20 ], or sensitization with carbonaceous materials [ 21 ]. Doping with C promotes the charge transfer from the bulk TiO 2 to its surface inducing visible-light-driven photocatalytic activity but also increasing the available surface for adsorption (initial step of photocatalytic reaction) and oxidation [ 22 ].…”

Co-CNT/TiO2 composites effectively improved the photocatalytic degradation of malachite green

“…Especially the preparation of new ternary materials. The ternary compounds have been made using a variety of metal ions, such as the Ag/TiO 2 /CNT [9], the TiO 2 /CNT/Pd [10], the CNT/TiO 2 /ZnO [11,12], the Au/TiO 2 @CNTs [13], et al These composites not only exhibit their intrinsic properties, but also exhibit synergistic or cooperative effects. On the one hand, composites made from (CNT)-based materials have higher surface areas, superior e-conductivity, and higher adsorption capabilities.…”