Synthesis of Hedgehoglike F-TiO₂(B)/CNT Nanocomposites for Sonophotocatalytic and Photocatalytic Degradation of Malachite Green (MG) under Visible Light: Kinetic Study

Abstract

The present study describes the preparation of hedgehoglike F-doped titanium dioxide bronze (F-TiO(B)) and its nanocomposites containing single-walled and multiwalled carbon nanotubes (SWCNTs, MWCNTs) by using combined ball milling-hydrothermal processes. Then, sonophotocatalytic and photocatalytic degradation of malachite green (MG) dye from aqueous solution using prepared materials was performed. The results show that F-TiO(B)/SWCNT displays a good sonophotocatalytic and photocatalytic performance among other products under visible light. In addition, they indicated that the efficiency of malachite green degradation is more than 95% and 91% for sonophotocatalytic and photocatalytic methods, respectively. Also, they demonstrate that the photocatalytic efficiency of catalysts increases in the presence of ultrasound and the sonophotocatalysis process followed a second-order kinetics. The catalysts have been characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). The analyzed data confirmed the presence of CNTs and fluorine (F) as dopant in all nanocomposites. The presented hybrid method reduced the band gap from 3.02 eV for F-TiO(B) to 2.7 eV for F-TiO(B)/SWCNT nanocomposite.

Effects of fluorine on photocatalysis

“…Similarly, the photoreactivity of F-doped TiO2 was improved after coupling with Bi2O3 to form a Bi2O3/F-doped TiO2 heterojunction [83]. Carbon nanotubes (CNTs) have also been used to modify F-doped TiO2, improving its photoreactivity by reducing the band gap from 3.02 to 2.7 eV and facilitating quick removal of the photo-generated electrons [84].…”

Fabrication, functionalization and performance of doped photocatalysts for dye degradation and mineralization: a review

“…According to the discussions in Fiyadh et al (2019), functionalization of CNTs can be covalent and non-covalent, whereby the former class is when functional groups get attached by covalent forces to the skeletal structure of CNTs through chemical reaction, and the latter type of functionalization occurs when functional groups coat the CNTs walls (Karousis et al 2010). Xia et al (2007), Mamba et al (2015), Zouzelka et al (2016), Réti et al (2016) and Panahian and Arsalani (2017) have indicated that CNTs can be combined with TiO 2 to generate composite structures for subsequent use as photocatalysts. Based on data in the literature, besides providing for a large surface area support to the TiO 2 particles, CNTs equally significantly retard the recombination of electrons and holes (Zouzelka et al 2016;Karthika and Arumugam 2017;Natarajan et al 2017).…”

Synthesis, Antimicrobial Activity, and Photocatalytic Performance of Ce Doped SnO2 Nanoparticles

“…It degrades malachite green dye ∼50% in 120 min of light irradiation. When compared with other metal oxides, it is found that undoped TiO 2 NPs and F doped TiO 2 NPs photocatalytically degraded 99.9 and 54.26% MG dye in 240 min and 120 min, respectively (Chen et al, 2007;Panahian and Arsalani, 2017). Sn doped TiO 2 has been reported degrading 85% MG in 340 min under light irradiation (Sayilkan et al, 2007), while SnO 2 NPs degraded 27% MG in 180 min under UV light irradiation (Kumar et al, 2016).…”