Visible-Light-Driven Carbon-Doped TiO₂-Based Nanocatalysts for Enhanced Activity toward Microbes and Removal of Dye

Abstract

Solar-driven photocatalytic approach is an attractive, clean, and effective way for decontamination of water. In this work, visible-light-activated TiO 2 nanoflakes (TNFs) and carbondoped TiO 2 nanoflakes (C-TNFs) were synthesized via a facile hydrothermal route using different carbon sources. The assynthesized nanostructures were successfully characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM), critically disclosing the anatase nature containing titanium−oxygen having flake/plateletlike morphology with ∼32 nm in size, respectively. The photocatalytic activity was characterized via the degradation of methylene blue (MB) and bacterial inactivation of Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The experimental results showed that C-TNFs significantly enhanced photocatalytic activity compared to bare TNFs. It was found that TNF nanocatalysts exhibited superior photocatalytic activity against photodegradation of MB (92.7%) and antibacterial activity (85.6%) under sunlight irradiation. In addition, reduced graphene oxide (RGO)-TNFs have a good recycling ability and are expected to be a promising candidate for photocatalytic applications under sunlight. Consequentially, the higher activity of RGO-TNF nanocatalysts under sunlight irradiation for organic degradation and bacterial inactivation implies that hydrothermal synthesis allows for the preparation of efficient and low-cost carbon-doped photocatalysts for the photodegradation of a wide range of environmental pollutants.

Visible Light-Induced Reactive Yellow 145 Discoloration: Structural and Photocatalytic Studies of Graphene Quantum Dot-Incorporated TiO2

“…In addition, it was found that adsorption capacity decreased with the increase in calcination temperature. Previous research demonstrated that the decoration of graphene on TiO 2 increases the pore size and surface area, which ultimately increase the adsorption capacity , …”

An Overview of Recent Developments in Improving the Photocatalytic Activity of TiO2-Based Materials for the Treatment of Indoor Air and Bacterial Inactivation

“…Several researchers reported that the doped photocatalyst activity increases after non-metal doping, as the electronic structure has been modified to extend the absorption of the photocatalyst into the visible-light region [ 57 ]. Various studies have shown non-metal doping of TiO 2 , such as Nitrogen-doped TiO 2 [ 58 ], carbon-doped TiO 2 [ 59 , 60 , 61 ], sulfur-doped TiO 2 [ 62 , 63 ], boron-doped TiO 2 [ 64 ] and phosphorus-doped TiO 2 [ 65 ]. Vaiano et al studied recyclable visible-light active N-doped TiO 2 photocatalysts coated on glass spheres using a simple sol-gel method.…”

Simple Low Temperature Technique to Synthesize Sillenite Bismuth Ferrite with Promising Photocatalytic Performance

“… 4 However, due to its wide band gap ( E g = 3.2 eV), titania only responds to ultraviolet irradiation, which accounts for only ∼3–4% of the whole solar spectrum. 5 Hence, developing new visible light-active photocatalysts is of significant research and technological interest among the scientific community. 6 − 8 …”

“…The majority of research has so far focused on the titania (TiO 2 ) photocatalyst, which has a strong oxidizing ability and chemical stability . However, due to its wide band gap ( E g = 3.2 eV), titania only responds to ultraviolet irradiation, which accounts for only ∼3–4% of the whole solar spectrum . Hence, developing new visible light-active photocatalysts is of significant research and technological interest among the scientific community. − …”

“…4 However, due to its wide band gap (E g = 3.2 eV), titania only responds to ultraviolet irradiation, which accounts for only ∼3−4% of the whole solar spectrum. 5 Hence, developing new visible light-active photocatalysts is of significant research and technological interest among the scientific community. 6−8 Bismuth ferrites, a large group of transition-metal oxides, including perovskite, mullite, and sillenite-type structural compounds have lately sparked the interest of researchers due to their superior fundamental physics and wide-ranging technological applications.…”