Facile synthesis and characterization of anatase TiO2/g-CN composites for enhanced photoactivity under UV–visible spectrum

Abstract

For the purpose of atmospheric NO removal, anatase TiO2/g-CN photocatalytic composites were prepared by using a facile template-free calcination route in atmospheric conditions. Considerably fiscal NP400 and laboratory-grade melamine were used as the precursor of the composites. Additionally, samples were prepared with different wt. ratios of TiO2 and melamine by using two distinct calcination temperatures (550°C/600°C). The morphological attributes of the composites were assessed with X-ray diffraction, scanning and transmission electron microscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy. Additionally, the optical traits were evaluated and compared using UVvisible diffuse reflectance spectroscopy and photoluminescence analysis. Finally, the photodegradation potentials for atmospheric NO by using the as-prepared composites were assessed under both UV and visible light irradiation. All the composites showed superior NO oxidation compared to NP400 and bulk g-CN. For the composites prepared by using the calcination temperature of 550°C, the maximum NO removal was observed when the NP400 to melamine ratio was 1:2, irrespective of the utilized light irradiation type. Whereas for increased calcination temperature (600°C), the maximum NO removal was observed at the precursor mix ratio of 1:3 (NP400:melamine). Successfully narrowed energy bandgaps were perceived in the as-prepared composites. Moreover, a subsequent drop in NO2 generation during NO oxidation was observed under both UV and visible light irradiation. Interestingly, higher calcination temperature during the synthesis of the catalysts has shown a significant drop in NO2 generation during the photodegradation of NO.

Fabrication of TiO2 Spheres and a Visible Light Active α-Fe2O3/TiO2-Rutile/TiO2-Anatase Heterogeneous Photocatalyst from Natural Ilmenite

“…The diffraction peaks at 25.20, 35.92, and 63.13° are attributed to (101), (105), and (204) crystalline planes of TiO 2 (anatase). 12 However, it was very difficult to isolate all crystalline planes of the anatase. The shielding effect of Fe 3 O 4 had taken place during the precipitation.…”

Hydrophilic/Hydrophobic Silane Grafting on TiO2 Nanoparticles: Photocatalytic Paint for Atmospheric Cleaning

“…It is clear from these equations that the adsorbed O 2 and H 2 O play a very significant role in the photooxidation of atmospheric NO. During photooxidation, O 2 is employed to trap the generated e − on the TiO 2 surface, and •OH radicals are formed from H 2 O by confining the generated h + on the TiO 2 surface, leading to NO oxidation and produce by-products like NO 2 and NO 3 − [14,15]. Therefore, when the sample is subjected to UV radiation, the photooxidation of NO takes place spontaneously.…”

“…A laboratory-scale photocatalytic reactor was used, following ISO 22197-1, to examine the extent of NO x photooxidation. The specifics of the method are listed elsewhere [14][15][16]. Figure 10 shows the diagram of the device used to test the photocatalytic efficiency of the as-prepared samples.…”

“…Regardless of which form it takes, TiO 2 is commonly chosen as a photocatalyst because of its extraordinary oxidative capacity, chemical durability, and availability at an affordable price for photocatalytic degradation of both organic and inorganic pollutants [13]. Under UV (λ < 390 nm) irradiance, TiO 2 produces a series of photochemical reactions that promote electrons (e − ) from the valence band (VB) to the CB, leaving a positively charged hole (h + ) behind [14]. As a result of the generation of the e − and h + , reactive oxygen species (ROS), for instance, superoxide species (•O 2 − ) or hydroxyl radicals (•OH), are produced from the surrounding O 2 and H 2 O [15,16].…”

Preparation of High-Porosity B-TiO2/C3N4 Composite Materials: Adsorption–Degradation Capacity and Photo-Regeneration Properties

“…g-C 3 N 4 is a good semiconductor material with application potential that is metal free and has visible light responsiveness [ 8 , 9 , 10 ]. However, researchers found that g-C 3 N 4 still has many disadvantages such as low utilization of visible light, poor photoelectric conversion efficiency, and low specific surface area [ 11 ]. Since Serpone et al [ 12 ] first reported that a solid–solid heterojunction interface with good contact can be constructed from different coupled semiconductor materials to promote electron transfer between particles, more and more researchers have paid attention to different semiconductor materials.…”