Bi24O31Br10 nanosheets with controllable thickness for visible–light–driven catalytic degradation of tetracycline hydrochloride

Abstract

Tetracycline hydrochloride (TTCH), a typical antibiotic, is widespread in aqueous environment, and its efficient and cost-effective removal is greatly desired. Among various physicochemical methods for TTCH degradation, visible-light-driven catalytic degradation is a promising one because of its utilization of solar energy.Bismuth oxybromide nanosheets have been found to be as efficient visible-light-driven photocatalysts, but the impact of thickness on their photocatalytic activity remains unclear. In this work, for the first time a series of thickness-controllable Bi 24 O 31 Br 10 nanosheets were synthesized without any surfactants, and their photocatlytic degradation of TTCH was explored. The photocatalytic degradation of TTCH was found to rely greatly on the generated free radicals and photogenerated h + , which were formed by the photogenerated charge carriers. The experimental results clearly demonstrate that a decrease in thickness could enhance the separation and transportation efficiency of charge carriers and that the thinnest Bi 24 O 31 Br 10 nanosheets exhibited the best performance for photocatalytic TTCH degradation. Our findings might be helpful to expand the potential applications of bismuth oxybromide photocatalysts in water and wastewater treatment, and provide a new strategy for the modification of nanostructural photocatalysts.

Bismuth‐Based Photocatalysts for Solar Photocatalytic Carbon Dioxide Conversion

“…For example, the groups of Wang and Chen used this methodt os ynthesize as eries of Bi x O y X z photocatalysts. [39][40][41][42][43] In recent years, the successful syntheses of Bi 3 O 4 X( X= Cl, Br), [44][45][46][47][48] Bi 4 O 5 X 2 (X = Br,I ), [49][50][51][52][53][54] Bi 5 O 7 X (X = Cl, Br,I ), [55][56][57][58] Bi 7 O 9 I 3 , [59][60][61] Bi 12 O 17 X 2 (X = Br,I ), [62][63][64][65][66][67][68][69] Bi 12 O 15 Cl 6 , [39,70] andB i 24 O 31 X 10 (X = Cl,B r) [38,[71][72][73][74] werer eported. As shown in Figure 5, layered Bi 12 O 17 Cl 2 nanosheets with {001} facet exposure were prepared at pH 13.6.…”

“…As shown in Figure 13 aa nd Ta ble 1, the band gaps of most Bi-based photocatalystsa re lower than 3.0 eV.T hey can be excited by visible light. [69][70][71][72][73][74] As showni nF igure13a,e lectrons at the CB of almost all Bi-based photocatalytic materials cannot directly reduce CO 2 into hydrocarbonsd ue to the more positive potentialt han that of the standard redox potentials of CH 4 /CO 2 (À0.24 V), CH 3 OH/CO 2 (À0.38V), HCHO/CO 2 (À0.48 V), CO/CO 2 (À0.53 V), and HCOOH/CO 2 (À0.61 V). The conduction band minimum (CBM) in most cases is constructed from Bi 6p states.…”

“…[96,97] Based on previous reports,t he CBM potential can be adjusted by changingt he bismuth atomic ratio. [69][70][71][72][73][74] As showni nF igure13a,e lectrons at the CB of almost all Bi-based photocatalytic materials cannot directly reduce CO 2 into hydrocarbonsd ue to the more positive potentialt han that of the standard redox potentials of CH 4 /CO 2 (À0.24 V), CH 3 OH/CO 2 (À0.38V), HCHO/CO 2 (À0.48 V), CO/CO 2 (À0.53 V), and HCOOH/CO 2 (À0.61 V). However,i th as been provedt hat many Bi-based photocatalystsc an be used forC O 2 reduction; this implies that light-induced surface defects adsorb and activate CO 2 molecules.T he redox potentials of C x O y H z /CO 2 (ads) are then lower than that of the CBM of Bi-based photocatalysts.…”

Solid Base Bi24O31Br10(OH)δ with Active Lattice Oxygen for the Efficient Photo‐Oxidation of Primary Alcohols to Aldehydes

“…2.5 eV, Figure S2 in the Supporting Information). According to the Mott–Schottky analysis reported previously, the conduction‐band minimum (CBM) and valence‐band maximum (VBM) of Bi 24 O 31 Br 10 are located at about −0.5–−0.8 V and about 1.7–1.9 V vs. the standard hydrogen electrode (SHE), suggesting that alcohol oxidation and O 2 reduction are thermodynamically feasible (Figure d).…”

Visible‐Light‐Driven Selective Oxidative Coupling of Amines to Imines by Bismuth‐Rich Bismuth Oxybromide in Water

“…[25,26] Amonga ll Bi-O-Xp hotocatalysts, bismuth oxybromide (Bi-O-Br) displays the most suitable band gap and band structure and as such is the mostw idely used. [28][29][30] Therefore, we investigated bismuth-richB i-O-Br for the photocatalytic oxidative coupling of amines to imines in water under normalp ressure andt emperature and blue light (l = 455 nm). [28][29][30] Therefore, we investigated bismuth-richB i-O-Br for the photocatalytic oxidative coupling of amines to imines in water under normalp ressure andt emperature and blue light (l = 455 nm).…”