Nanocomposites of GaBr₃ and BiBr₃ Nanocrystals on BiOBr for the Photocatalytic Degradation of Dyes and Tetracycline

Abstract

In recent past decades, semiconductor-based photocatalysts have been studied worldwide as a promising technique for the degradation of organic dyes in wastewater. In this study, a nanoplate-like Bi-based heterojunction (BGB-1, -2, and -3) has been prepared for the first time through the in situ formation of BiBr 3 and GaBr 3 nanocrystals on the surface of BiOBr via a facile water bath method, followed by the hydrothermal process with a change in the composition. Multiple physiochemical processes such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared are analyzed to reveal the structural properties. The Brunauer−Emmett−Teller, UV−vis diffusereflectance, and photoluminescence spectra have been utilized for detailed analysis of the surface area, grain boundary, lattice imperfections, and light absorption properties. The photocatalytic activity and quantum efficiency of the as-synthesized nanocomposites have been evaluated by the photodegradation of Rhodamine B (RhB), methylene blue, methyl orange, Congo red, phenolic compounds, and colorless antibiotic tetracycline with visible-light illumination. Compared to pure BiOBr or the precursor materials, Bi-based nano/photocatalysts exhibit a significantly enhanced photocatalytic activity. Moreover, it is seen that the nanocomposite with a composition of 0.1 mol of Ga(NO 3 ) 3 •xH 2 O and 2.9 mol of Bi(NO 3 ) 3 • 5H 2 O (BGB-1 nanocomposite) shows the highest photocatalytic activity against RhB degradation (∼100% within 20 min) and tetracycline antibiotic (∼92% within 20 min). The significantly improved photoreactivity has been ascribed to the effective separation of photogenerated electron−hole pairs and superoxide radical anions ( • O 2 − ). The hole (h + ) also greatly impacts the degradation mechanism. Bi-based nanocomposites are found to kill Gram-positive and Gram-negative bacteria. These nanocomposites have been designed as efficient visible-light-driven heterojunction photocatalytic materials with significant antibacterial activity for wastewater purification.

Direct Z-Scheme g-C3N5/Cu3TiO4 Heterojunction Enhanced Photocatalytic Performance of Chromene-3-Carbonitriles Synthesis under Visible Light Irradiation

“…Altogether, e − s instantaneously migrate from the CB of Cu 3 TiO 4 (−2.09 eV) to the CB of g-C 3 N 5 , (−0.64 eV). However, the potential energy (V vs. NHE) of e − s from g-C 3 N 5 is much lower than O 2 /O 2 − (−0.33 V) [76], which designates that these electrons are unable to reducing O 2 to •O 2 − . Correspondingly, holes of Cu 3 TiO 4 have inadequate potential energy to oxidize H 2 O to •OH (•OH/H 2 O = 2.34 V vs. NHE) [77].…”

Efficient photodegradation of methyl red dye by kaolin clay supported zinc oxide nanoparticles with their antibacterial and antioxidant activities

“…Photocatalysis is a simple approach to resolve the discharged dye issue and minimise water pollution problems. Through this process, the degradation of a variety of dyes ensued within aquatic media [ [16] , [17] , [18] ]. For this purpose, nanomaterials-based photocatalysts have been found more efficient to convert the typical dye molecules to CO 2 , H 2 O and other harmless by-products [ 19 ].…”

Thickness Modification of BiOBr Nanosheets by Sn-TiO2 for Enhanced Photocatalytic Degradation of Antibiotics

“…9,10 However, the photocatalytic efficiency of pure BiOBr appears limited due to the rapid compounding of photogenerated carriers. 11,12 Conditioning morphological engineering to expose more reaction site has been demonstrated to be an effective method. 13,14 For example, Wang et al 15 reported fine shell thickness engineering of colloidal CdS/ CdSe core/shell QDs and its effect on photocatalytic H 2 production in water.…”

“…BiOBr has received a lot of attention as an emerging and important ternary material because of its extraordinary crystal structure and physicochemical properties with high response in visible light. , However, the photocatalytic efficiency of pure BiOBr appears limited due to the rapid compounding of photogenerated carriers. , Conditioning morphological engineering to expose more reaction site has been demonstrated to be an effective method. , For example, Wang et al reported fine shell thickness engineering of colloidal CdS/CdSe core/shell QDs and its effect on photocatalytic H 2 production in water. The H 2 photogenerated quantum yield (ΦH 2 ) of CdS/CdSe core–shell quantum dots could reach 9.420% under 30 nm light irradiation at a suitable shell layer thickness, which was 49% higher than that of CdS cores.…”