Bi₁₂O₁₇Cl₂/(BiO)₂CO₃ Nanocomposite Materials for Pollutant Adsorption and Degradation: Modulation of the Functional Properties by Composition Tailoring

Abstract

Bi12O17Cl2/(BiO)2CO3 nanocomposite materials were studied as bifunctional systems for depuration of wastewater. They are able to efficiently adsorb and decompose rhodamine B (RhB) and methyl orange (MO), used as model pollutants. Bi12O17Cl2/(BiO)2CO3 nanocomposites were synthesized at room temperature and ambient pressure by means of controlled hydrolysis of BiCl3 in the presence of a surfactant (Brij 76). Cold treatments of the pristine samples with UV light or thermal annealing at different temperatures (370–500 °C) and atmospheres (air, Ar/30% O2) were adopted to modulate the relative amounts of Bi12O17Cl2/(BiO)2CO3 and hence the morphology, surface area, ζ-potential, optical absorption in the visible range, and the adsorption/degradation of pollutants. The best performance was achieved by (BiO)2CO3-rich samples, which adsorbed 80% of MO and decomposed the remaining 20% by visible light photocatalysis. Irrespective of the dye, all of the samples were able to almost complete the adsorption step within 10 min contact time. Bi12O17Cl2-rich composite materials displayed a lower adsorption ability, but thanks to the stronger absorption in the visible range they behaved as more effective photocatalysts. The obtained results evidenced the ability of the employed strategy to modulate sample properties in a wide range, thus pointing out the effectiveness of this approach for the synthesis of multifunctional inorganic materials for environmental remediation

Controlled and cellulose eco-friendly synthesis and characterization of Bi2O2CO3 quantum dot nanostructures (QDNSs) and drug delivery study

“…The broad absorption band centered at 1400–1450 cm −1 and 850 cm −1 correspond to the antisymmetric stretching mode of the CO 3 group in Bi 2 O 2 CO 3 nanostructures 36 . The absorption band appeared in the area 3300–3400 cm −1 is related to amine (N–H) bands in Bi 2 O 2 CO 3 /sorafenib formulation 37 . Two strong bands at 675 cm −1 and 1230 cm −1 with different intensities are respectively attributed to stretching of the alkene=C–F and Alkyl-Halide–C–F bonds in sorafenib molecular structures.…”

A Review of Bismuth(III)-Based Materials for Remediation of Contaminated Sites

“…Coprecipitation is a convenient method for preparing composite materials containing phases with a common metal ion but different counterions (e.g., basic bismuth nitrate and carbonate or oxide) or phases with different metal ions and the same counterion. A basic Bi 3+ chloride/carbonate composite material was prepared by controlled hydrolysis of BiCl 3 dissolved in ethanolic HCl via addition of HCl solution containing a nonionic surfactant at ambient temperature, subsequent aging for 5 h at 65 °C, and precipitation of the Bi 12 O 17 Cl 2 /Bi 2 O 2 CO 3 composite (45:55% ratio) with 2 M LiOH . The Bi 2 O 2 CO 3 had a Sillén structure (typical for bismutite), and the layered Bi 12 O 17 Cl 2 phase contained Bi oxide sheets with intercalated chloride ions, forming aggregated nanoflakes of irregular shape.…”

“…Because of their light-harvesting properties and charge transport characteristics, the use of Bi-based materials to remediate organic contaminants by heterogeneous photocatalysis has been extensively demonstrated. ,,,,,,,,,,,,,− The photocatalysis mechanism is based on the use of photoinduced electrons and holes on the surface of Bi-based semiconductors as sources of reducing and oxidizing equivalents, respectively, leading to the decomposition of adsorbed organic contaminants . However, these advantageous photocatalytic properties cannot be exploited for in situ remediation of contaminants in the subsurface, so only a limited number of examples of Bi-based photocatalysts, for ex situ remediation of organic contaminants, are provided here.…”

A Bi/BiOI/(BiO)2CO3 heterostructure for enhanced photocatalytic NO removal under visible light

“…BiOI is a typical p-type semiconductor where the Fermi level is located close to the valence band (VB) [34][35][36]. The Fermi level of n-type (BiO)2CO3 is close to the CB [37][38][39]. The coupling of an n-type semiconductor ((BiO)2CO3) to a p-type photosensitizer (BiOI) enables the Fermi level of (BiO)2CO3 and BiOI to shift to the same level, thus forming a p-n heterojunction [40][41][42].…”