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1.
Environ Res ; 241: 117653, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37980982

RESUMO

When confronted with wastewater that is characterized by complex composition, stable molecular structure, and high concentration, relying solely on photocatalytic technology proves inadequate in achieving satisfactory degradation results. Therefore, the integration of other highly efficient degradation techniques has emerged as a viable approach to address this challenge. Herein, a novel strategy was employed whereby the exfoliated g-C3N4 nanosheets (CNs) with exceptional photocatalytic performance, were intimately combined with porous rod-shaped cobalt ferrite (CFO) through a co-calcination process to form the composite CFO/CNs, which exhibited remarkable efficacy in the degradation of various organic pollutants through the combination of photocatalysis and Fenton-like process synergistically, exemplified by the representative case of tetracycline hydrochloride (TCH, 200 mL, 50 mg/L). Specifically, under 1 mM of peroxymonosulfate (PMS) and illumination conditions, 50 mg of 1CFO/9CNs achieved a TCH removal ratio of ∼90% after 60 min of treatment. Furthermore, this work comprehensively investigated the influence of various factors, including catalyst and PMS dosages, solution pH, and the presence of anions and humate, on the degradation efficiency of pollutants. Besides, quenching experiments and EPR tests confirmed the establishment of an S-scheme heterojunction between CNs and CFO, which facilitated the effective spatial separation of photoexcited charge carriers and preserved the potent redox potential of photogenerated electrons and holes. This work offers a valuable reference for the integration of photocatalysis with the PMS-based Fenton-like process.


Assuntos
Elétrons , Poluentes Ambientais , Porosidade , Iluminação
2.
Environ Res ; 246: 118128, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38191037

RESUMO

In this investigation, a magnetic nanobiocomposite, denoted as CoFe2O4/Activated Carbon integrated with Chitosan (CoFe2O4/AC@Ch), was synthesized based on a microwave-assisted for the efficacious adsorption of P-nitroaniline (PNA). The physicochemical properties of the said nano biocomposite were thoroughly characterized using a suite of analytical methodologies, namely FESEM/EDS, BET, FTIR, XRD, and VSM. The results confirm the successful synthesis of the nanobiocomposite, with its point of zero charge (pHZPC) determined to be 6.4. Adsorptive performance towards PNA was systematically examined over a spectrum of conditions, encompassing variations in PNA concentration (spanning 10-40 mg/L), adsorbent concentration (10-200 mg/L), contact periods (2.5-22.5 min), and solution pH (3-11). Upon optimization, the conditions converged to an adsorbent concentration of 200 mg/L, pH 5, PNA concentration of 10 mg/L, and a contact duration of 22.5 min, under which an impressive PNA adsorption efficacy of 98.6% was attained. Kinetic and isotherm analyses insinuated the adsorption mechanism to adhere predominantly to the pseudo-second-order kinetic and Langmuir isotherm models. The magnetic nanocomposite was recovered and used in 4 cycles, and the absorption rate reached 86%, which shows the good stability of the magnetic nanocomposite in wastewater treatment. Conclusively, these empirical outcomes underscore the viability of the formulated magnetic nanobiocomposite as a potent, recyclable adsorbent for the proficient extraction of PNA from aqueous matrices.


Assuntos
Poluentes Químicos da Água , Adsorção , Poluentes Químicos da Água/análise , Compostos de Anilina , Cinética , Fenômenos Magnéticos , Concentração de Íons de Hidrogênio
3.
Environ Res ; 258: 119484, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38914250

RESUMO

The present research utilizes a sol-gel approach to create a CoFe2O4/g-C3N4 nanocomposite (NC) and explored several analytical methods to evaluate physical, chemical and optical based characteristics via XRD, FTIR, UV-vis, SEM/EDS and XPS for the prepared pure CoFe2O4, g-C3N4, and CoFe2O4/g-C3N4 NC. The XRD results show that the prepared g-C3N4, CoFe2O4, exhibits hexagonal and cubic phases respectively, whereas the g-C3N4/CoFe2O4 NC exhibit mixing of two phases. The energy band gaps for pure g-C3N4, CoFe2O4 and g-C3N4/CoFe2O4 NC values are viz., 2.75, 1.3, and 2.4 eV. As photocatalysts, synthesized materials were utilized for the decomposition of Rhodamine-B (RhB) dye. Finally, the CoFe2O4/g-C3N4 NC showed good performance of photocatalysis for RhB dye disintegration under the stimulus of visible light. According to the induced visible light, the rate at which the photocatalytic degradation occurs for the CoFe2O4/g-C3N4 NC was found to be 57% in 120 min and this is greater when compared with pure catalysts like CoFe2O4 (28%) and g-C3N4 (10%). These outcomes suggest that the prepared NC have efficiently worked during the photocatalytic process compared with its pure materials.


Assuntos
Cobalto , Compostos Férricos , Grafite , Rodaminas , Cobalto/química , Rodaminas/química , Compostos Férricos/química , Grafite/química , Compostos de Nitrogênio/química , Fotólise , Nanocompostos/química , Catálise , Nitrilas/química
4.
Environ Res ; 254: 118676, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38763285

RESUMO

In this study, magnetic CoFe2O4-PAC nanocatalysts were synthesized through facile hydrothermal and co‒precipitation approaches with ultrasonic irradiation, which were used for the treatment of hypersaline petrochemical wastewater (HPCW). When an ultrasound‒induced synthesis process (US@CoFe2O4‒PAC) was used, a more efficient and stable magnetic spinel CoFe2O4‒PAC nanocatalyst was developed. The application of this nanocatalyst as a PMS activator, not only caused eradication of 90.4% of chemical oxygen demand (COD) of a HPCW after 90 min reaction time under the optimum conditions (pH 5-6, catalyst dose 1.0 g/L and 1.0 mM PMS), but also led to marginal leaching of iron (314 µg/L) and cobalt (95 µg/L) from the nanocatalyst. Recycling experiments over five consecutive runs showed a negligible decrease (7.2%) in COD removal efficiency which proved the stability and reusability of magnetic US@CoFe2O4-PAC. Two main mechanisms of adsorption and catalytic oxidation processes (homogeneous and heterogeneous PMS) are involved simultaneously in the PMS/US@CoFe2O4-PAC system, which are responsible for the destruction of refractory contaminants of HPCW through the generation of SO4•‒ and OH• radicals. COD of HPCW was mainly removed through SO4•- radical attack (73.6%) and the biodegradability of HPCW was enhanced dramatically after 90 min reaction time. The germination index (GI) of raw HPCW was increased 17.1 ± 4.2% and 24.3 ± 8.8% after 15 and 90 min reaction time, respectively, even PMS/US@CoFe2O4-PAC system showed less impact on phytotoxicity mitigation. Hence, it can be recommended to dilute the effluent before using for irrigational purpose. The findings of this study present practical significance of spinel US@CoFe2O4-PAC, which is an environment‒friendly catalyst, easy to handle and can sustain long‒term operation for the treatment of recalcitrant hypersaline wastewater and the other potential practical applications.


Assuntos
Cobalto , Compostos Férricos , Águas Residuárias , Poluentes Químicos da Água , Águas Residuárias/química , Cobalto/química , Compostos Férricos/química , Catálise , Biodegradação Ambiental , Eliminação de Resíduos Líquidos/métodos , Salinidade
5.
Environ Res ; 258: 119395, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38909944

RESUMO

In this study, we report the development of a novel CuOx(3 wt%)/CoFe2O4 nanocubes (NCs) photocatalyst through simple co-precipitation and wet impregnation methods for the efficient photocatalytic degradation of triclosan (TCS) pollutants. Initially, rod-shaped bare CoFe2O4 was synthesized using a simple co-precipitation technique. Subsequently, CuOx was loaded in various percentages (1, 2, and 3 wt%) onto the surface of bare CoFe2O4 nanorods (NRs) via the wet impregnation method. The synthesized materials were systematically characterized to evaluate their composition, structural and electrical characteristics. The CuOx(3 wt%)/CoFe2O4 NCs photocatalyst exhibited superior photocatalytic degradation efficiency of TCS (89.9%) compared to bare CoFe2O4 NRs (62.1 %), CuOx(1 wt%)/CoFe2O4 (80.1 %), CuOx(2 wt%)/CoFe2O4 (87.0 %) under visible light (VL) irradiation (λ ≥ 420 nm), respectively. This enhanced performance was attributed to the improved separation effectiveness of photogenerated electron (e-) and hole (h+) in CuOx(3 wt%)/CoFe2O4 NCs. Furthermore, the optimized CuOx(3 wt%)/CoFe2O4 NCs exhibited strong stability and reusability in TCS degradation, as demonstrated by three successive cycles. Genetic screening on Caenorhabditis elegans showed that CuOx(3 wt%)/CoFe2O4 NCs reduced ROS-induced oxidative stress during TCS photocatalytic degradation. ROS levels decreased at 30, 60, and 120-min intervals during TCS degradation, accompanied by improved egg hatching rates. Additionally, expression levels of stress-responsible antioxidant proteins like SOD-3GFP and HSP-16.2GFP were significantly normalized. This study demonstrates the efficiency of CuOx(3 wt%)/CoFe2O4 NCs in degrading TCS pollutants, offers insights into toxicity dynamics, and recommends its use for future environmental remediation.


Assuntos
Cobalto , Cobre , Triclosan , Triclosan/química , Triclosan/toxicidade , Animais , Cobre/química , Catálise , Cobalto/química , Compostos Férricos/química , Compostos Férricos/toxicidade , Luz , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/efeitos da radiação , Fotólise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
6.
Sensors (Basel) ; 24(6)2024 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-38544189

RESUMO

In this study, a novel flexible ethanol gas sensor was created by the deposition of a CoFe2O4 (CFO) thin film on a thin mica substrate using the pulsed laser deposition technique. Transition electron microscopy (TEM) investigations clearly demonstrated the successful growth of CFO on the mica, where a well-defined interface was observed. Ethanol gas-sensing studies showed optimal performance at 200 °C, with the highest response of 19.2 to 100 ppm ethanol. Operating the sensor in self-heating mode under 7 V applied voltage, which corresponds to a temperature of approximately 200 °C, produced a maximal response of 19.2 to 100 ppm ethanol. This aligned with the highest responses observed during testing at 200 °C, confirming the sensor's accuracy and sensitivity to ethanol under self-heating conditions. In addition, the sensor exhibited good selectivity to ethanol and excellent flexibility, maintaining its high performance after bending and tilting up to 5000 times. As this is the first report on flexible self-heated CFO gas sensors, we believe that this research holds great promise for the future development of high-quality sensors based on this approach.

7.
Environ Geochem Health ; 46(8): 261, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38916678

RESUMO

A simple sol-gel combustion process was employed for the creation of MFe2O4 (M=Ni, Co) nanoparticles. The synthesized nanoparticles, acting as both photocatalysts and gas sensors, were analyzed using various analytical techniques. MFe2O4 (M=Ni, Co) material improved the degradation of methylene blue (MB) under UV-light irradiation, serving as an enhanced electron transport medium. UV-vis studies demonstrated that NiFe2O4 achieved a 60% degradation, while CoFe2O4 nanostructure exhibited a 76% degradation efficacy in the MB dye removal process. Furthermore, MFe2O4 (M=Ni, Co) demonstrated chemosensitive-type sensor capabilities at ambient temperature. The sensor response and recovery times for CoFe2O4 at a concentration of 100 ppm were 15 and 20, respectively. Overall, the synthesis of MFe2O4 (M=Ni, Co) holds the potential to significantly improve the photocatalytic and gas sensing properties, particularly enhancing the performance of CoFe2O4. The observed enhancements make honey MFe2O4 (M=Ni, Co) a preferable choice for environmental remediation applications.


Assuntos
Cobalto , Compostos Férricos , Azul de Metileno , Níquel , Cobalto/química , Cobalto/análise , Níquel/química , Níquel/análise , Compostos Férricos/química , Azul de Metileno/química , Nanopartículas Metálicas/química , Gases , Catálise , Raios Ultravioleta , Recuperação e Remediação Ambiental/métodos , Nanopartículas/química , Óxido de Alumínio , Óxido de Magnésio
8.
Environ Geochem Health ; 46(8): 302, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38990227

RESUMO

In this study, a highly efficient CoFe2O4-anchored g-C3N4 nanocomposite with Z-scheme photocatalyst was developed by facile calcination and hydrothermal technique. To evaluate the crystalline structure, sample surface morphology, elemental compositions, and charge conductivity of the as-synthesized catalysts by various characterization techniques. The high interfacial contact of CoFe2O4 nanoparticles (NPs) with g-C3N4 nanosheets reduced the optical bandgap from 2.67 to 2.5 eV, which improved the charge carrier separation and transfer. The photo-degradation of methylene blue (MB) and rhodamine B (Rh B) aqueous pollutant suspension under visible-light influence was used to investigate the photocatalytic degradation activity of the efficient CoFe2O4/g-C3N4 composite catalyst. The heterostructured spinel CoFe2O4 anchored g-C3N4 photocatalysts (PCs) with Z-scheme show better photocatalytic degradation performance for both organic dyes. Meanwhile, the efficiency of aqueous MB and Rh B degradation in 120 and 100 min under visible-light could be up to 91.1% and 73.7%, which is greater than pristine g-C3N4 and CoFe2O4 catalysts. The recycling stability test showed no significant changes in the photo-degradation activity after four repeated cycles. Thus, this work provides an efficient tactic for the construction of highly efficient magnetic PCs for the removal of hazardous pollutants in the aquatic environment.


Assuntos
Cobalto , Compostos Férricos , Azul de Metileno , Nanocompostos , Rodaminas , Poluentes Químicos da Água , Cobalto/química , Compostos Férricos/química , Catálise , Nanocompostos/química , Rodaminas/química , Poluentes Químicos da Água/química , Azul de Metileno/química , Fotólise , Luz , Compostos Inorgânicos de Carbono/química , Nitrilas/química , Processos Fotoquímicos , Compostos de Nitrogênio/química , Grafite
9.
Angew Chem Int Ed Engl ; : e202413774, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39136239

RESUMO

Developing sustainable energy solutions is critical for addressing the dual challenges of energy demand and environmental impact. In this study, a zinc-nitrate (Zn-NO3-) battery system was designed for the simultaneous production of ammonia (NH3) via the electrocatalytic NO3- reduction reaction (NO3RR) and electricity generation. Continuous wave CO2 laser irradiation yielded precisely controlled CoFe2O4@nitrogen-doped carbon (CoFe2O4@NC) hollow nanocubes from CoFe Prussian blue analogs (CoFe-PBA) as the integral electrocatalyst for NO3RR in 1.0-M KOH, achieving a remarkable NH3 production rate of 10.9 mgh-1cm-2 at -0.47 V versus RHE with exceptional stability. In-situ and ex-situ methods revealed that the CoFe2O4@NC surface transformed into high-valent Fe/CoOOH active-species, optimizing the adsorption energy of NO3RR (*NO2 and *NO species) intermediates. Furthermore, DFT calculations validated the possible NO3RR pathway on CoFe2O4@NC starting with NO3- conversion to *NO2 intermediates, followed by reduction to *NO. Subsequent protonation forms the *NH and *NH2 species, leading to NH3 formation via final protonation. The Zn-NO3- battery utilizing the CoFe2O4@NC cathode exhibits dual functionality by generating electricity with a stable open-circuit voltage of 1.38-V versus Zn/Zn2+ and producing NH3. This study inspires the simple design of low-cost catalysts for NO3RR-to-NH3 conversion and positions the Zn-NO3- battery as a promising technology for industrial applications.

10.
Anal Biochem ; 662: 114914, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36272452

RESUMO

The fabrication of electrochemical sensing platforms for cancer monitoring by quantifying circulating tumor cells (CTCs) in blood holds promise for providing a low-cost, rapid, feasible, and safe approach for cancer diagnosis. Here, we isolate cancer cells using CoFe2O4 nanoparticles functionalized with folic acid and chitosan as an inexpensive magnetic nanoprobe. This electrochemical cytosensing platform was realized using polyaniline-folic acid nanohybrids with a three-dimensional hierarchical structure that presents abundant affinity sites toward overexpressed folate bioreceptors on cancer cells, in addition to retaining satisfied conductivity. Furthermore, 3D modeling and simulation of the polyaniline-folic acid structures were conducted to investigate the stable complex between aniline and folate, and the interaction between the polyaniline-folate complex and folate receptor alpha1, a bioreceptor on MCF-7 was revealed for the first time. The limit of detection was calculated to be 4 cells mL-1 with a linear range from 50 to 106 cells mL-1.


Assuntos
Técnicas Biossensoriais , Nanopartículas , Nanoestruturas , Ácido Fólico , Nanoestruturas/química , Nanopartículas/química , Compostos de Anilina/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas
11.
Int J Mol Sci ; 24(11)2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37298534

RESUMO

Low-cost, sustainable hydrogen production requires noble metal-free electrocatalysts for water splitting. In this study, we prepared zeolitic imidazolate frameworks (ZIF) decorated with CoFe2O4 spinel nanoparticles as active catalysts for oxygen evolution reaction (OER). The CoFe2O4 nanoparticles were synthesized by converting agricultural bio-waste (potato peel extract) into economically valuable electrode materials. The biogenic CoFe2O4 composite showed an overpotential of 370 mV at a current density of 10 mA cm-2 and a low Tafel slope of 283 mV dec-1, whereas the ZIF@CoFe2O4 composite prepared using an in situ hydrothermal method showed an overpotential of 105 mV at 10 mA cm-2 and a low Tafel slope of 43 mV dec-1 in a 1 M KOH medium. The results demonstrated an exciting prospect of high-performance noble metal-free electrocatalysts for low-cost, high-efficiency, and sustainable hydrogen production.


Assuntos
Nanopartículas , Zeolitas , Agricultura , Eletrodos , Oxigênio , Hidrogênio
12.
J Environ Manage ; 326(Pt A): 116584, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36403318

RESUMO

In this study, the photocatalytic activity of ZnO was effectively improved via its combination with spinel cobalt ferrite (SCF) nanoparticles. The catalytic performance of ZnO@SCF (ZSCF) was investigated in coupling with UV irradiation and ultrasound (US), as a heterogeneous sono-photocatalytic process, for the decontamination of phenanthrene (PHE) from contaminated soil. Soil washing tests were conducted in a batch environment, after extraction assisted by using Tween 80. Several characterization techniques such as XRD, FESEM-EDS, BET, TEM, UV-vis DRS, PL and VSM were utilized to determine the features of the as-prepared catalysts. ZSCF showed an excellent catalytic activity toward degradation of PHE in the presence of US and UV with a significant synergic effect. It was found that more than 93% of PHE (35 mg/L) and 87.5% of TOC could be eliminated by the integrated ZSCF/US/UV system under optimum operational conditions (pH: 8.0, ZSCF: 1.5 g/L, UV power: 6.0 W and US power: 70 W) within 90 min of reaction. After five times of use, ZSCF illustrated good reusability in the decontamination of PHE (87%) and TOC (79%). Quenching tests revealed the contribution of h+, HO• and e- species during PHE degradation over ZSCF/UV/US and an S-scheme photocatalytic mechanisms was proposed for the possible charge transfer routes under the ZSCF system. This study provides the important role of SCF in enhancing the ZnO photocatalytic activity due to its high performance, easy recovery and excellent durability, which it make an efficient and promising catalyst in environmental clean-up applications.


Assuntos
Tensoativos , Óxido de Zinco , Solo
13.
Molecules ; 28(10)2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37241810

RESUMO

A magnetically induced self-assembled graphene nanoribbons (GNRs) method is reported to synthesize MFe2O4/GNRs (M = Co,Ni). It is found that MFe2O4 compounds not only locate on the surface of GNRs but anchor on the interlayers of GNRs in the diameter of less than 5 nm as well. The in situ growth of MFe2O4 and magnetic aggregation at the joints of GNRs act as crosslinking agents to solder GNRs to build a nest structure. Additionally, combining GNRs with MFe2O4 helps to improve the magnetism of the MFe2O4. As an anode material for Li+ ion batteries, MFe2O4/GNRs can provide high reversible capacity and cyclic stability (1432 mAh g-1 for CoFe2O4/GNRs and 1058 mAh g-1 for NiFe2O4 at 0.1 A g-1 over 80 cycles).

14.
Small ; 18(3): e2104213, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34816590

RESUMO

Multiferroics with simultaneous electric and magnetic orderings are highly desirable for sensing, actuation, data storage, and bio-inspired systems, yet developing flexible materials with robust multiferroic properties at room temperature is a long-term challenge. Utilizing water-soluble Sr3 Al2 O6 as a sacrificial layer, the authors have successfully self-assembled a freestanding BaTiO3 -CoFe2 O4 heteroepitaxial nanostructure via pulse laser deposition, and confirmed its epitaxial growth in both out-of-plane and in-plane directions, with highly ordered CoFe2 O4 nanopillars embedded in a single crystalline BaTiO3 matrix free of substrate constraint. The freestanding nanostructure enjoys super flexibility and mechanical integrity, not only capable of spontaneously curving into a roll, but can also be bent with a radius as small as 4.23 µm. Moreover, piezoelectricity and ferromagnetism are demonstrated at both microscopic and macroscopic scales, confirming its robust multiferroicity at room temperature. This work establishes an effective route for flexible multiferroic materials, which have the potential for various practical applications.


Assuntos
Nanoestruturas , Compostos de Bário/química , Nanoestruturas/química , Temperatura , Titânio/química
15.
Environ Res ; 215(Pt 1): 114269, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36103925

RESUMO

The global occurrence of textile dyes pollution has recently emerged, posing a serious threat to ecological systems. To abate dye contamination, we here developed a novel magnetic porous CoFe2O4@MIL-53(Al) nanocomposite by incorporating magnetic CoFe2O4 nanoparticles with MIL-53(Al) metal-organic framework. This nanocomposite possessed a surface area of 197.144 m2 g-1 and a pore volume of 0.413 cm3 g-1. The effect of contact time (5-120 min), concentration (5-50 mg L-1), dosage (0.1-1.0 g L-1), and pH (2-10) on Congo red adsorption was clarified. CoFe2O4@MIL-53(Al) could remove 95.85% of Cong red dye from water with an accelerated kinetic rate of 0.6544 min-1 within 10 min. The kinetic and isotherm models showed the predominance of Bangham and Temkin. According to Langmuir, the maximum uptake capacities of CoFe2O4@MIL-53(Al), CoFe2O4, and MIL-53(Al) adsorbents were 43.768, 17.982, and 15.295 mg g-1, respectively. CoFe2O4@MIL-53(Al) was selected to optimize Cong red treatment using Box-Behnken experimental design. The outcomes showed that CoFe2O4@MIL-53(Al) achieved the highest experimental uptake capacity of 35.919 mg g-1 at concentration (29.966 mg L-1), time (14.926 min), and dosage (0.486 g L-1). CoFe2O4@MIL-53(Al) could treat dye mixture (methylene blue, methyl orange, Congo red, malachite green, and crystal violet) with an outstanding removal efficiency of 81.24% for 30 min, and could be reused up to five cycles. Therefore, novel recyclable and stable CoFe2O4@MIL-53(Al) is recommended to integrate well with real dye treatments systems.


Assuntos
Estruturas Metalorgânicas , Nanocompostos , Poluentes Químicos da Água , Purificação da Água , Adsorção , Corantes/química , Vermelho Congo , Violeta Genciana , Azul de Metileno/química , Nanocompostos/química , Água , Poluentes Químicos da Água/química
16.
Environ Res ; 205: 112424, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34838758

RESUMO

The activation of peroxymonosulfate (PMS) by nanocatalysts has shown promise as an effective wastewater treatment protocol. Magnetic CoFe2O4/Ag-nanoparticles (NPs) anchored on functionalized multiwalled carbon nanotubes (fMWCNTs), a support material, were synthesized using a one-pot solvothermal method. The surface morphologies and physicochemical properties of the CoFe2O4/Ag-fMWCNT hybrid nanocomposite catalyst were investigated by powder X-ray diffraction analysis, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and nitrogen adsorption-desorption isotherms. The activity of the nanocomposite combined with PMS (serving as an activator) toward the degradation of rhodamine B, methylene blue, methyl orange, and methyl red was investigated. The obtained optimal 0.02 g CoFe2O4/Ag-fMWCNTs exhibited the highest PMS activation performance, with a removal percentage of 100% for 20 ppm dye concentration at pH 6.5 within 14 min. In addition, the rhodamine B degradation product was investigated by analyzing the intermediate products by liquid chromatography/mass spectrometry (LC-MS). The homogeneous distribution of CoFe2O4/Ag NPs on fMWCNTs accelerated PMS activation and enhanced the catalytic degradation of dyes. The effects of the reaction parameters on the dye degradation efficiency were investigated by using different nanocatalysts (fMWCNTs, CoFe2O4/fMWCNTs, and CoFe2O4/Ag-fMWCNTs) as well as by varying the pH (3-11), dye concentration (10-50 mg/l), catalyst dose (0.002-0.3 g), and PMS dose (0.02-0.1 g). Quenching experiments revealed that sulfate radicals are primarily responsible for rhodamine B degradation. A plausible mechanism for catalytic PMS activation was also proposed. Complete decolorization occurred within the first few minutes of the reaction. Furthermore, the catalytic activity of the CoFe2O4/Ag-fMWCNT/PMS hybrid nanocomposite remained stable after five successive cycles. This study verifies the applicability of CoFe2O4/Ag-fMWCNTs as an ultrafast catalyst for the complete removal of persistent organic pollutants via PMS activation, revealing their promising application in wastewater treatment.


Assuntos
Nanocompostos , Nanotubos de Carbono , Cobalto , Corantes , Compostos Férricos , Peróxidos
17.
Environ Res ; 215(Pt 2): 114270, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36100101

RESUMO

Nowadays, antibiotic water pollution is an increasingly dangerous environmental threat. Thus, water treatment is essential for their reduction and removal. In recent decades, photocatalysts have attracted much attention due to their influential role in solving this issue. The photocatalytic process, which is one of the green processes and part of advanced oxidation processes, can be a good choice for treating contaminated water containing non-degradable organic matter. However, the design of high-performance photocatalysts under free sunlight can be challenging. In this study, g-C3N4-Ca, Mg codoped CoFe2O4-ZnO (gCN-CFO-ZnO) nanocomposite photocatalyst was applied in removing penicillin G (PENG) from drug effluents. Also, the effects of contaminant concentration, initial pH, irradiation time, and zinc oxide ratio in the nanocomposites were investigated. The hydrothermal method was carried out to prepare the appropriate composites. Then, the obtained products were characterized by powder X-Ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FT-IR), Raman, field-emission scanning and transmission electron microscope (FE-SEM&TEM), energy dispersive X-Ray (EDX), diffuse reflectance spectroscopy (DRS), vibrating sample magnetometer (VSM) and Photoluminescence (PL) techniques. According to the findings, the degradation of PENG in an acidic environment occurred remarkably; under the same conditions, with decreasing pH from 9 to 5 in the gCN-CFO-ZnO (33.33%) nanocomposite, the degradation efficiency grew from 47% to 74%. Also, the degradation rate of PENG in gCN-CFO-ZnO (16.66%) and gCN-CFO-ZnO (50%) nanocomposites under optimal conditions (pH = 5, PENG the concentration of 10 ppm, and irradiation time of 120 min) was achieved 52% and 60%, respectively. Further, gCN-CFO-ZnO (33.33%) nanocomposite showed higher efficiency in PENG degradation compared to the other two nanocomposites.


Assuntos
Nanocompostos , Óxido de Zinco , Antibacterianos , Catálise , Luz , Nanocompostos/química , Penicilina G , Pós , Espectroscopia de Infravermelho com Transformada de Fourier , Óxido de Zinco/química
18.
Environ Res ; 212(Pt C): 113394, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35537501

RESUMO

The co-existence of organic contaminants and heavy metals including 4-chlorophenol (4-CP) and Cr(VI) in aquatic system have become a challenging task in the wastewater treatment. Herein, the synchronous photocatalytic decomposition of 4-CP and Cr(VI) over new Z-scheme CoFe2O4/P-BiOBr heterojunction nanocomposites were revealed. In this work, the nanocomposites were successfully developed via a surfactant-free hydrothermal method. The heterojunction interface was created by decorating magnetic CoFe2O4 nanoparticles onto P-BiOBr nanosheets. The as-fabricated CoFe2O4/P-BiOBr nanocomposites substantially improved the synchronous decomposition of 4-CP and Cr(VI) compared to the single-phase component samples under visible light irradiation. Particularly, the 30-CoFe2O4/P-BiOBr nanocomposite displayed the best photocatalytic performance, which decomposed 95.6% 4-CP and 100% Cr(VI) within 75 min. The photocatalytic improvement was assigned to the Z-scheme heterojunction assisted charge migration between CoFe2O4 and P-BiOBr, and the acceleration of charge carrier separation was validated by the findings of charge dynamics measurements. The harmful 4-CP was photodegraded into smaller organics whereas the Cr(VI) was photoreduced into Cr(III) after 30-CoFe2O4/P-BiOBr photocatalysis, and the good recyclability of fabricated nanocomposite in photocatalytic reaction also showed promising potential for practical applications in environmental remediation. Finally, the radical quenching tests confirmed that there existed the Z-scheme path of charge migration in CoFe2O4/P-BiOBr nanocomposite, which was the mechanism responsible for its high photoactivity.

19.
Environ Toxicol ; 37(12): 2877-2888, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36073959

RESUMO

This study aimed to synthesize the nickel (Ni) doped cobalt ferrite (CFO) nanoparticles and to determine its anticancer effect on breast cancer MCF-7 cells. The various concentrations of Ni (0.2%, 0.4%, 0.6%, 0.8%, and 1%) doped CFO nanoparticles were synthesized using Coriandrum sativum extracts by precipitation technique. The synthesized Ni-CFO was characterized by X-ray diffraction, Fourier transform infrared spectroscopic, transmission electron microscopy, and vibrating sample magnetometer analyses. The results show that 0.8% Ni-CFO nanoparticles showed good magnetic properties and antioxidant activity than other concentrations of Ni-CFO. The results showed that the administration of 0.8% Ni-CFO nanoparticles promoted apoptosis, and reduced cell adhesion and migration of MCF-7 cells, as demonstrated by increased lipid peroxidation, decreased antioxidant levels such as superoxide dismutase, catalase, and glutathione peroxidase, and increased formation of reactive oxygen species. Moreover, administration of 0.8% Ni-CFO nanoparticles decreased the Bcl-2 expression while activating the expression of p53, Bax, and cleaved caspase 3, 8 and 9 protein expression. Notably, 0.8% Ni-CFO treatment reduced phospho-PI3K, phospho-Akt, and phospho-mTOR expression levels. As a result, via altering apoptotic related proteins, 0.8% Ni-CFO induced cell death. Therefore, the 0.8% Ni-CFO could be utilized to treat breast cancer.


Assuntos
Neoplasias da Mama , Nanopartículas , Humanos , Feminino , Células MCF-7 , Níquel/farmacologia , Níquel/química , Espécies Reativas de Oxigênio/metabolismo , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Cobalto/farmacologia , Apoptose , Antioxidantes/farmacologia , Proteínas Reguladoras de Apoptose , Serina-Treonina Quinases TOR , Antibacterianos/farmacologia
20.
J Environ Manage ; 310: 114693, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35189554

RESUMO

In this study, 3D flower-like magnetic CoFe-LDHs/CoFe2O4 was prepared by a facile urea hydrothermal method and utilized to activate peroxymonosulfate (PMS) for degrading aniline (AN). CoFe-LDHs/CoFe2O4 was systematically characterized to explore the relationship between its structure and catalytic performance. Compared with CoFe-LDHs synthesized by co-precipitation method, CoFe-LDHs/CoFe2O4 exhibited three dimensional structure and larger specific surface, which could increase the degradation efficiency of AN markedly. 96% of 10 mg L-1 AN could be eliminated by 0.3 mM PMS and 50 mg L-1 CoFe-LDHs/CoFe2O4 at initial pH 6 within 5 min and the total organic carbon (TOC) removal efficiency could be high to 52.8% in 30 min. CoFe-LDHs/CoFe2O4 can be separated by a magnet easily due to its magnetism, which makes it avoid secondary pollution and provide convenience. After recycling six times, the degradation efficiency still maintained at 92.6%. Besides, CoFe-LDHs/CoFe2O4/PMS can degrade AN in practical water samples effectively. In addition, the possible mechanism of CoFe-LDHs/CoFe2O4/PMS system for the degradation of AN was proposed. The radical scavenging experiments confirmed that SO4·-, HO· and O2·- were involved and SO4·- played a dominant role in the degradation of AN, and it was further proved by electron Paramagnetic Resonance (EPR) as well. Our findings can provide some new insights into the efficient and skillful design and application of heterogeneous catalyst for environmental remediation.


Assuntos
Magnetismo , Peróxidos , Compostos de Anilina , Fenômenos Magnéticos , Peróxidos/química
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