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1.
J Colloid Interface Sci ; 678(Pt C): 1012-1021, 2024 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-39326162

RESUMO

1O2 generation over (001) or (010) facet exposed BiOCl (B001 or B010) with/without phosphate modification were studied from the aspects of excitons involved energy transfer route, the O2- oxidation based charge transfer route and the H2O2 oxidation by HClO. Phosphate modification not only enhance charge separation thus result in H2O2 oxidation by HClO to release 1O2 but also weaken excitonic effect in the confined layer of BiOCl accordingly affect 1O2 generation via energy transfer. Considering [001] orientation favors the formation of excitons than that of [010] direction over BiOCl, excitons loss was hardly compensated by the H2O2 oxidation by HClO for 1O2 generation over phosphate modified B001. Nevertheless, limited excitonic effect makes the O2- oxidation by h+ via charge transfer as dominant route for 1O2 yielding over B010, the extra H2O2 oxidation with HClO after phosphate modification significantly enhance 1O2 generation over B010 followed with 2.2 times higher carbamazepine photodegradation activity. The initial attack of CC bond via 1O2 to form epoxide played important roles on carbamazepine degradation. This study demonstrated that the facet-specific phosphate modification of photocatalysts can finely tune reactive 1O2 species for superior pharmaceuticals degradations.

2.
J Colloid Interface Sci ; 677(Pt A): 610-619, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39116559

RESUMO

Photocatalytic nitrogen reduction is a promising green technology for ammonia synthesis under mild conditions. However, the poor charge transfer efficiency and weak N2 adsorption/activation capability severely hamper the ammonia production efficiency. In this work, heteropoly blue (r-PW12) nanoparticles are loaded on the surface of ultrathin bismuth oxychloride nanosheets with oxygen vacancies (BiOCl-OVs) by electrostatic self-assembly method, and a series of xr-PW12/BiOCl-OVs heterojunction composites have been prepared. Acting as a robust support, ultrathin two-dimensional (2D) structure of BiOCl-OVs inhibits the aggregation of r-PW12 nanoparticles, enhancing the interfacial contact between r-PW12 and BiOCl. More importantly, the existence of oxygen vacancies (OVs) provides abundant active sites for efficient N2 adsorption and activation. In combination of the enhanced light absorption and promoted photogenerated carriers separation of xr-PW12/BiOCl-OVs heterojunction, under simulated solar light, the optimal 7r-PW12/BiOCl-OVs exhibits an excellent photocatalytic N2 fixation rate of 33.53 µmol g-1h-1 in pure water, without the need of sacrificial agents and co-catalysts. The reaction dynamics is also monitored by in situ FT-IR spectroscopy, and an associative distal pathway is identified. Our study demonstrates that construction of heteropoly blues-based heterojunction is a promising strategy for developing high-performance N2 reduction photocatalysts. It is anticipated that combining of different defects with heteropoly blues of different structures might provide more possibilities for designing highly efficient photocatalysis systems.

3.
Cureus ; 16(7): e65080, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39171070

RESUMO

Introduction  MXenes (Ti3C2) represent a group of two-dimensional inorganic compounds, produced through a top-down exfoliation method. They comprise ultra-thin layers of transition metal carbides, or carbonitrides, and exhibit hydrophilic properties on their surfaces. Utilizing Ti3C2 BiOCl nanoparticles for their antimicrobial and antioxidant attributes involves enhancing synthesis, processing, and characterization techniques. Materials and method  To prepare Ti3C2 MXene, dissolve 1.6 g of LiF in 20 ml of 9M HCl. Slowly add 1 g of Ti3AlC2 (titanium aluminum carbide) powder to the solution while stirring. Etch at 35°C for 24 h to remove Al layers from Ti3AlC2, leaving Ti3C2 layers. Wash the mixture with distilled water and ethanol until the pH is around 6. Collect the washed sediment by centrifugation and sonicate it in distilled water for 1 h. Centrifuge to remove unexfoliated particles. For BiOCl synthesis, dissolve 2 mmol of Bi(NO3)3·5H2O (bismuth nitrate pentahydrate) in 10 ml of 2M HCl (hydrochloric acid) with 0.5 g of PVP (polyvinylpyrrolidone). Transfer the solution to a Teflon-lined autoclave, fill it with distilled water up to 80%, and heat at 160°C for 24 h. Collect the precipitate by centrifugation, wash, and dry at 60°C for 12 h. Disperse BiOCl nanoparticles in distilled water, sonicate for 30 min, add Ti3C2 MXene dispersion, stir for 2 h, collect, wash, dry, and calcine at 400°C for 2 h. Result  The Scanning Electron Microscope (SEM) utilizes electrons, rather than light, to generate highly magnified images. Energy Dispersive X-ray Spectroscopy (EDS) complements SEM by analyzing the X-ray spectrum emitted when a solid sample is bombarded with electrons, enabling localized chemical analysis. In SEM imaging, incorporating an X-ray spectrometer allows for both element mapping and point analysis. The SEM image of the prepared samples reveals accordion-like multilayer structures in BiOCl, characterized by thin sheet-like structures with numerous pores. EDS, relying on X-ray emissions from electron bombardment, facilitates detailed chemical analysis at specific locations within the sample.  Conclusion  Our research has shed light on the synthesis and characterization processes of two-dimensional Ti3C2 BiOCl nanoparticles, revealing their remarkable antimicrobial and antioxidant properties.

4.
Environ Sci Technol ; 58(13): 6049-6057, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38525996

RESUMO

High Cl- concentration in saline wastewater (e.g., landfill leachate) limits wastewater purification. Catalytic Cl- conversion into reactive chlorine species (RCS) arises as a sustainable strategy, making the salinity profitable for efficient wastewater treatment. Herein, aiming to reveal the structure-property relationship in Cl- utilization, bismuth oxychloride (BiOCl) photocatalysts with coexposed {001} and {110} facets are synthesized. With an increasing {001} ratio, the RCS production efficiency increases from 75.64 to 96.89 µg L-1 min-1. Mechanism investigation demonstrates the fast release of lattice Cl- as an RCS and the compensation of ambient Cl-. Correlation analysis between the internal electric field (IEF, parallel to [001]) and normalized efficiency on {110} (kRCS/S{110}, perpendicular to [001]) displays a coefficient of 0.86, validating that the promoted carrier dynamics eventually affects Cl- conversion on the open layered structure. The BiOCl photocatalyst is well behaved in ammonium (NH4+-N) degradation ranging from 20 to 800 mg N L-1 with different chlorinity (3-12 g L-1 NaCl). The sustainable Cl- conversion into RCS also realizes 85.4% of NH4+-N removal in the treatment of realistic landfill leachate (662 mg of N L-1 NH4+-N). The structure-property relationship provides insights into the design of efficient catalysts for environment remediation using ambient Cl-.


Assuntos
Compostos de Amônio , Bismuto , Poluentes Químicos da Água , Águas Residuárias , Poluentes Químicos da Água/química , Salinidade
5.
Molecules ; 29(6)2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38543000

RESUMO

In recent years, oxygen vacancy (VO) engineering has become a research hotspot in the field of photocatalysis. Herein, an efficient GQDs/BiOCl-VO heterojunction photocatalyst was fabricated by loading graphene quantum dots (GQDs) onto BiOCl nanosheets containing oxygen vacancies. ESR and XPS characterizations confirmed the formation of oxygen vacancy. Combining experimental analysis and DFT calculations, it was found that oxygen vacancy promoted the chemical adsorption of O2, while GQDs accelerated electron transfer. Benefiting from the synergistic effect of oxygen vacancy, GQDs, and dye sensitization, the as-prepared GQDs/BiOCl-VO sample exhibited improved efficiency for RhB degradation under visible-light irradiation. A 2 wt% GQDs/BiOCl-VO composite effectively degraded 98% of RhB within 20 min. The main active species were proven to be hole (h+) and superoxide radical (·O2-) via ESR analysis and radical trapping experiments. This study provided new insights into the effective removal of organic pollutants from water by combining defect engineering and quantum dot doping techniques in heterojunction catalysts.

6.
Heliyon ; 9(11): e21270, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37954349

RESUMO

In this work, bismuth oxychloride (BiOCl) and Sn-doped BiOCl (SBCl) with improved visible light photocatalytic activity were synthesized via the co-precipitation method. The XRD analysis determined the tetragonal phase of BiOCl, 1 %, 5 %, and 10 % SBCl. The crystallite sizes were in the range of 20-34 nm. These results confirmed that the Sn ion was successfully incorporated into the BiOCl lattice. This was further confirmed by FT-IR and Raman analysis. The optical properties, such as the band gap energy, were studied using UV-vis DRS. It was found that doping BiOCl with Sn has a minor effect on the band gap tuning. BET shows that the SBCl samples have acquired a larger specific surface area (14.66-42.20 m2/g) than BiOCl (13.49 m2/g). The photocatalytic performance showed that SBCl samples have higher photocatalytic activity than BiOCl in degrading Rhodamine B (RhB) dye under visible light irradiation. Among the SBCl samples, 5 % SBCl exhibited the highest photocatalytic efficiency which degraded 91.2 % of the RhB dye in 60 min. Moreover, the photoelectrochemical activities of the as-synthesized BiOCl and SBCl were investigated using linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in the dark and under visible light irradiation. Both studies showed that SBCl exhibits enhanced photoelectrochemical activities than BiOCl. Hence, it can be suggested that SBCl possesses visible light active properties and can be potentially used as a photocatalyst and photoelectrode material.

7.
Environ Sci Pollut Res Int ; 30(37): 87830-87850, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37434054

RESUMO

Fe-BOC-X photocatalyst was successfully prepared by solvothermal method. The photocatalytic activity of Fe-BOC-X was determined by ciprofloxacin (CIP), a typical fluoroquinolone antibiotic. Under sunlight irradiation, all Fe-BOC-X showed better CIP removal performance than original BiOCl. In comparison, the photocatalyst with iron content of 50 wt% (Fe-BOC-3) has excellent structural stability and the best adsorption photodegradation efficiency. The removal rate of CIP (10 mg/L) by Fe-BOC-3 (0.6 g/L) reached 81.4% within 90 min. At the same time, the effects of photocatalyst dosage, pH, persulfate, persulfate concentration, and combinations of different systems (PS, Fe-BOC-3, Vis/PS, Vis/Fe-BOC-3, Fe-BOC-3/PS, and Vis/Fe-BOC-3/PS) on the reaction were systematically discussed. In reactive species trapping experiments, electron spin resonance (ESR) signals revealed that the photogenerated holes (h+), hydroxyl radical (•OH), sulfate radical (•SO4-), and superoxide radical (•O2-) played an important role in CIP degradation; hydroxyl radicals (•OH) and sulfate radicals (•SO4-) play a major role. Various characterization methods have demonstrated that Fe-BOC-X has larger specific surface area and pore volume than original BiOCl. UV-vis DRS indicate that Fe-BOC-X has wider visible light absorption and faster photocarrier transfer and provides abundant surface oxygen absorption sites for effective molecular oxygen activation. Accordingly, a large number of active species were produced and participated in the photocatalytic process, thus effectively promoting the degradation of ciprofloxacin. Based on HPLC-MS analysis, two possible decomposition pathways of CIP were finally proposed. The main degradation pathways of CIP are mainly due to the high electron density of piperazine ring in CIP molecule, which is mainly attacked by various free radicals. The main reactions include piperazine ring opening, decarbonylation, decarboxylation, and fluorine substitution. This study can better open up a new way for the design of visible light driven photocatalyst and provide more ideas for the removal of CIP in water environment.


Assuntos
Ciprofloxacina , Compostos Férricos , Ciprofloxacina/química , Luz , Oxigênio , Piperazinas , Catálise
8.
Adv Healthc Mater ; 12(30): e2301497, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37285593

RESUMO

Sonodynamic therapy (SDT) combines ultrasound and sonosensitizers to produce toxic reactive oxygen species (ROS) for cancer cell killing. Due to the high penetration depth of ultrasound (US), SDT breaks the depth penetration barrier of conventional photodynamic therapy for the treatment of deeply seated tumors. A key point to enhance the therapeutic efficiency of SDT is the development of novel sonosensitizers with promoted ability for ROS production. Herein, ultrathin Fe-doped bismuth oxychloride nanosheets with rich oxygen vacancies and bovine serum albumin coating on surface are designed as piezoelectric sonosensitizers (BOC-Fe NSs) for enhanced SDT. The oxygen vacancies of BOC-Fe NSs provide electron trapping sites to promote the separation of e- -h+ from the band structure, which facilitates the ROS production under the ultrasonic waves. The piezoelectric BOC-Fe NSs create a built-in field and the bending bands, further accelerating the ROS generation with US irradiation. Furthermore, BOC-Fe NSs can induce ROS generation by a Fenton reaction catalyzed by Fe ion with endogenous H2 O2 in tumor tissues for chemodynamic therapy. The as-prepared BOC-Fe NSs efficiently inhibited breast cancer cell growth in both in vitro and in vivo tests. The successfully development of BOC-Fe NSs provides a new nano-sonosensitiser option for enhanced SDT for cancer therapy.


Assuntos
Neoplasias , Terapia por Ultrassom , Humanos , Oxigênio , Espécies Reativas de Oxigênio , Bioensaio , Ferro , Linhagem Celular Tumoral
9.
J Colloid Interface Sci ; 640: 839-850, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36905893

RESUMO

Sonodynamic therapy (SDT) is considered as a new-rising strategy for cancer therapeutics, but the inefficient production of reactive oxygen species (ROS) by current sonosensitizers seriously hinders its further applications. Herein, a piezoelectric nanoplatform is fabricated for enhancing SDT against cancer, in which manganese oxide (MnOx) with multiple enzyme-like activities is loaded on the surface of piezoelectric bismuth oxychloride nanosheets (BiOCl NSs) to form a heterojunction. When exposed to ultrasound (US) irradiation, piezotronic effect can remarkably promote the separation and transport of US-induced free charges, and further enhance ROS generation in SDT. Meanwhile, the nanoplatform shows multiple enzyme-like activities from MnOx, which can not only downregulate the intracellular glutathione (GSH) level, but also disintegrate endogenous hydrogen peroxide (H2O2) to generate oxygen (O2) and hydroxyl radicals (•OH). As a result, the anticancer nanoplatform substantially boosts ROS generation and reverses tumor hypoxia. Ultimately, it reveals remarkable biocompatibility and tumor suppression in a murine model of 4 T1 breast cancer under US irradiation. This work provides a feasible pathway for improving SDT using piezoelectric platforms.


Assuntos
Peróxido de Hidrogênio , Neoplasias , Camundongos , Humanos , Animais , Espécies Reativas de Oxigênio/metabolismo , Neoplasias/terapia , Oxigênio/metabolismo , Linhagem Celular Tumoral
10.
J Environ Manage ; 333: 117411, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36758401

RESUMO

As an environmentally benign disinfection strategy, photocatalytic bacterial inactivation using nanoparticles involves photogenerated reactive species that cause cellular oxidative stress. Rationalising the structural performance of photocatalysts for the practical uses such as wastewater treatment has attracted significant attention; however, the contribution of reactive species to their photocatalytic antibacterial activities at the molecular and transcriptomic levels remains unclear. In this study, nontoxic bismuth oxychloride (BiOCl) photocatalysts with different nanoscale thicknesses, including nanosheets (Ns, ∼5.4 nm), nanoplates (Np, ∼1.8 nm), and ultra-nanosheets (Uns, ∼1.1 nm), were synthesised under hydrothermal conditions. Among the three samples, BiOCl Uns exhibited the most effective photocatalytic degradation efficiency with the calculated apparent rate constant of 0.0294 min-1, ∼4 times faster than that of Ns, whereas BiOCl Ns possessed the most pronounced bactericidal effect (5.4 log inactivation). Such findings indicate the distinct role of the photoactive species responsible for photocatalytic bacterial inactivation. Moreover, transcriptome analysis of Escherichia coli after photocatalytic treatment revealed that the underlying photocatalytic antibacterial mechanism at the genetic expression level involves cellular component biosynthesis, energy metabolism, and material transportation. Notably, the differences between BiOCl Ns and BiOCl Uns were significantly enriched in purine metabolism. Therefore, the cost-effective preparation of BiOCl nanosheets with nanoscale thickness-modulated photocatalytic antibacterial activity has remarkable potential for sustainable environmental and biomedical applications.


Assuntos
Nanopartículas , Catálise , Bismuto/química , Antibacterianos
11.
Polymers (Basel) ; 15(3)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36771887

RESUMO

The ever-present risk of surgical items being retained represents a real medical peril for the patient and potential liability issues for medical staff. Radiofrequency scanning technology is a very good means to substantially reduce such accidents. Radiolucent medical-grade polyvinyl chloride (PVC) used for the production of medical items is filled with radiopaque agents to enable X-ray visibility. The present study proves the suitability of bismuth oxychloride (BiOCl) and documents its advantages over the classical radiopaque agent barium sulfate (BaSO4). An addition of BiOCl exhibits excellent chemical and physical stability (no leaching, thermo-mechanical properties) and good dispersibility within the PVC matrix. As documented, using half the quantity of BiOCl compared to BaSO4 will provide a very good result. The conclusions are based on the methods of rotational rheometry, scanning electron microscopy, dynamic mechanical analysis, atomic absorption spectroscopy, and the verification of zero leaching of BiOCl out of a PVC matrix. X-ray images of the studied materials are presented, and an optimal concentration of BiOCl is evaluated.

12.
Chemosphere ; 315: 137742, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36608890

RESUMO

Tailoring energy band structure of bismuth oxychloride (BiOCl)-based photocatalysts by virtue of the metal and/or non-metal elements is one of the promising strategy to address environmental issues, especially plays a crucial role in water remediation. However, it still remains a great challenge to balance the light-harvesting and charge carriers separation. Herein, a feasible strategy was proposed for the simultaneous integration of energy-band modulation and surface hydroxylation to alleviate the as-mentioned contradiction and long-standing issues. By using a simple one-pot hydrothermal method, In-S-co-doped BiOCl photocatalyst coupling with surface hydroxylation (denoted as In/BOC-S-OH) was prepared by the simultaneous co-precipitation and ripening process and exhibited a good photocatalytic activity for removing tetracycline (TC) under visible light-irradiation than the counterparts of In-doped BiOCl (In/BOC), S-doped BiOCl (In/BOC-S) or surface -OH modification BiOCl (In/BOC-OH). Such satisfied photocatalytic efficiency benefits from the synergistic effect on the visible light capture, charge migration and separation associated with the introduction of intermediate energy levels and surface defect, respectively. Accompanying with the introduction of In and S hetero-atoms intercalation, both the potentials of valence and conduction bands were adjusted and the reduction of the bandgap could promote the capture of photons. Meanwhile, the powerful polarization effect associated with the non-uniform charge distribution could promote the special separation of carriers. More importantly, the surface defects induced by hydroxylation could act as traps for photogenerated electrons to stimulate the rapid separation of carriers, thereby causing the cleavage of antibiotics on the catalytic surface. This research offers a reliable strategy and promising scheme via effective solar energy conversion and charge carrier separation to advance photocatalytic wastewater remediation.


Assuntos
Luz , Tetraciclina , Hidroxilação , Antibacterianos/química , Oxirredução
13.
Environ Technol ; 44(13): 1877-1889, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-34890301

RESUMO

This work mainly focuses on the preparation and performance study of SrTiO3-BiOCl composite photocatalysis. The SrTiO3-BiOCl photocatalysts are prepared via the facial microwave hydrothermal method. XRD, UV-vis DRS, SEM, TEM, XPS, N2 adsorption and desorption isothermal experiment, FT-IR, and PL are applied to characterize the prepared samples. The spherical particles of SrTiO3 grow on the flaky BiOCl, and the crystal size is uniform and evenly disperses on the BiOCl. The catalytic performance of the samples was evaluated over the degradation rates of methylene blue(MB). Typically, the clearance rates of MB reached to 99.65% over SrTiO3-BiOCl-50% under visible light, which was much higher than that of SrTiO3 and BiOCl (55.86%, 79.79%, respectively). The active species capturing experiments and ESR showed that the holes (h+) and ·OH are playing the main roles in the degradation process.


Assuntos
Bismuto , Micro-Ondas , Espectroscopia de Infravermelho com Transformada de Fourier , Bismuto/química , Compostos Orgânicos , Luz
14.
Chemosphere ; 307(Pt 2): 135967, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35952795

RESUMO

Controllable active site construction, crystal structure regulation and efficient charge separation are core issues in heterogeneous photo-Fenton. Herein, abundant oxygen vacancies and well-dispersed interfacial iron sites are simultaneously constructed in hierarchical nanosheet-assembled BiOCl microflowers. The composites exhibit superior performance in photo-Fenton oxidation of carbamazepine (10 mg L-1) with a low H2O2 concentration (1.3 mM). The high performance highly depends on the synergistic effects between oxygen vacancies and iron species. Rather than modulating the valence band, the involvements of oxygen vacancies and iron species could modify the conduction band of BiOCl. The presence of oxygen vacancies promotes the migration of photo-generated electrons and accelerates the redox cycling of ≡Fe(III)/≡Fe(II) to boost the activation of H2O2 to generate hydroxyl radicals, and oxygen vacancies can be well preserved after cyclic use. This work provides understanding on efficient utilization of oxygen vacancies and interfacial iron sites to assist photo-Fenton and the underlying electron transfer mechanism.


Assuntos
Ferro , Oxigênio , Carbamazepina , Catálise , Compostos Ferrosos , Peróxido de Hidrogênio/química , Ferro/química , Oxigênio/química
15.
J Control Release ; 349: 475-485, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35839934

RESUMO

Bismuth-based compounds are considered to be the best candidates for computed tomography (CT) imaging of gastrointestinal (GI) tract due to high X-ray absorption. Here, we report the introduction of polymer-coated bismuth oxychloride (BiOCl) nanosheets for highly efficient CT imaging in healthy mice and animal with colitis. We demonstrate simple, low cost and fast aqueous synthesis protocol which provides gram-quantity yield of chemically stable BiOCl nanosheets. The developed contrast gives 2.55-fold better CT enhancement compared to conventional contrast with negligible in vivo toxicity. As a major finding we report a regioselective CT imaging of GI tract by using nanoparticles coated with differentially charged polymers. Coating of nanoparticles with a positively charged polymer leads to their fast accumulation in small intestine, while the coating with negatively charged polymers stimulates prolonged stomach retention. We propose that this effect may be explained by a pH-controlled aggregation of nanoparticles in stomach. This feature may become the basis for advancement in clinical diagnosis of entire GI tract.


Assuntos
Bismuto , Polímeros , Animais , Bismuto/química , Trato Gastrointestinal/diagnóstico por imagem , Camundongos , Raios X
16.
J Colloid Interface Sci ; 622: 995-1007, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35567952

RESUMO

In view of the increasing threat of overuse of broad-spectrum antibiotics to water environment, here, a series of small molecular intercalated bismuth oxychloride (SBC-X) composite photocatalysts were successfully constructed by a simple stirring synthesis at room temperature. Among them, SBC-0.5 showed excellent photocatalytic performance against the three target broad-spectrum antibiotics in visible light, which was 3.06 times, 5.93 times and 11.64 times higher than that of monomer for degrading tetracycline, norfloxacin and ciprofloxacin, respectively. Through analysis, it was found that the excellent photocatalytic degradation performance of SBC-0.5 was mainly attributed to the greatly improved specific surface area, which increased to 14 times of monomer, providing a large number of reaction sites for the subsequent photocatalytic degradation. Besides, intercalated molecules as charge transfer bridges between nanosheets greatly accelerated the efficiency of photogenerated charge transfer between layers. Free radical trapping experiments and electron spin resonance indicated that superoxide anion radicals played a major role in the photocatalytic degradation, followed by singlet oxygen. Furthermore, nine potential degradation intermediates were identified, and the toxicity was greatly reduced confirmed by ECOSAR software prediction and soybean seed germination and seeding growth experiment. Our work will provide useful information for the purification of wastewater containing antibiotics.


Assuntos
Antibacterianos , Bismuto , Antibacterianos/farmacologia , Catálise , Luz , Tetraciclina , Águas Residuárias
17.
Chemosphere ; 297: 134122, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35257701

RESUMO

The nanostructured, inner-coupled Bismuth oxyhalides (BiOX0.5X'0.5; X, X' = Cl, Br, I; X≠X') heterostructures were prepared using Quercetin (Q) as a sensitizer. The present study revealed the tuning of the band properties of as-prepared catalysts. The catalysts were characterized using various characterization techniques for evaluating the superior photocatalytic efficiency and a better understanding of elemental interactions at interfaces formed in the heterojunction. The material (BiOCl0.5Br0.5-Q) reflected higher degradation of MO (about 99.85%) and BPA (98.34%) under visible light irradiation than BiOCl0.5I0.5-Q and BiOBr0.5I0.5-Q. A total of 90.45 percent of total organic carbon in BPA was removed after visible light irradiation on BiOCl0.5Br0.5-Q. The many-fold increase in activity is attributed to the formation of multiple interfaces between halides, conjugated π-electrons and multiple -OH groups of quercetin (Q). The boost in degradation efficiency can be attributed to the higher surface area, 2-D nanostructure, inhibited electron-hole recombination, and appropriate band-gap of the heterostructure. Photo-response of BiOCl0.5Br0.5-Q is higher compared to BiOCl0.5I0.5-Q and BiOBr0.5I0.5-Q, indicating better light absorption properties and charge separation efficiency in BiOCl0.5Br0.5-Q due to band edge position. First-principles Density Functional Theory (DFT) based calculations have also provided an insightful understanding of the interface formation, physical mechanism, and superior photocatalytic performance of BiOCl0.5Br0.5-Q heterostructure over other samples.


Assuntos
Luz , Quercetina , Catálise
18.
J Colloid Interface Sci ; 608(Pt 3): 2752-2759, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34785052

RESUMO

Rocking-chair capacitive deionization (RCDI), as the next generation technique of capacitive deionization, has thrived to be one of the most promising strategies in the desalination community, yet was hindered mostly by its relatively low desalination rate and stability. Motivated by the goal of simultaneously enhancing the desalination rate and structural stability of the electrode, this paper reports an anion-driven flow-through RCDI (AFT-RCDI) system equipped with BiOCl nanostructure coated carbon sponge (CS@BiOCl for short; its backbone is derived from commercially available melamine foam with minimum capital cost) as the flow-through electrode. Owning to the rational design of the composite electrode material with minimum charge transfer resistance and ultrahigh structure stability as well as the superior flow-through cell architecture, the AFT-RCDI displays excellent desalination performance (desalination capacity up to 107.33 mg g-1; desalination rate up to 0.53 mg g-1s-1) with superior long-term stability (91.75% desalination capacity remained after 30 cycles). This work provides a new thought of coupling anion capturing electrode with flow-through cell architecture and employing a low-cost CS@BiOCl electrode with commercially available backbone material, which could shed light on the further development of low-cost electrochemical desalination systems.

19.
Nanomaterials (Basel) ; 11(9)2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34578537

RESUMO

Photocatalysis is a powerful strategy to address energy and environmental concerns. Sulfur-doped BiOCl was prepared through a facial hydrothermal method to improve the photocatalytic performance. Experimental results and theoretical calculations demonstrated that the band structure of the sulfur-doped BiOCl was optimally regulated and the light absorption range was expanded. It showed excellent visible-light photocatalytic water oxidation properties with a rate of 141.7 µmol h-1 g-1 (almost 44 times of that of the commercial BiOCl) with Pt as co-catalyst.

20.
J Environ Manage ; 297: 113256, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34311251

RESUMO

The first systematic synthesis of bismuth oxychloride/bismuth oxybromide/graphitic carbon nitride (BiOxCly/BiOmBrn/g-C3N4) nano-composites used a controlled hydrothermal method. The structure, morphology and characteristic of BiOxCly/BiOmBrn/g-C3N4 photocatalyst were measured by XRD, UV-vis-DRS, FT-IR, FE-TEM, FE-SEM-EDS, PL, BET, HR-XPS and EPR. Under visible light irradiation, the photodegradation activity was evaluated for the decolorization of crystal violet (CV) and 2-hydroxybenzoic acid (2-HBA) in aqueous solution. The catalytic performance showed that, when using sample BB2C1-4-250-30 wt% g-C3N4 composite as a photocatalyst, the best reaction-rate-constant (k) was 0.071 h-1. It was 1.5 times higher than the k value of BB2C1-4-250 as a photocatalyst. From the scavenging effect of various scavengers, the results of EPR showed that reactive OH was the main scavenger, while O2-, h+ and 1O2 were the second scavenger in CV degradation. In this study, a possible photodegradation mechanism was proposed and discussed. In this work, our method of BiOxCly/BiOmBrn/g-C3N4 preparation could be used for future mass production and the BiOxCly/BiOmBrn/g-C3N4 composite materials could be applied to the environmental pollution control in future.


Assuntos
Bismuto , Luz , Catálise , Fotólise , Espectroscopia de Infravermelho com Transformada de Fourier
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