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1.
Environ Geochem Health ; 46(2): 63, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38302793

RESUMO

This study investigates the effect of boundary conditions and treatment-time on the electro-desalination of artificially-contaminated soil. The effect of ion exchange membranes (IEM), calcium chloride (CaCl2), and ethylenediaminetetraacetic acid (EDTA) on the removal of salt (i.e., Na+, Cl-, and Ca2+) and metal (i.e., Co2+ and Fe2+) ions from the soil by electrokinetic (EK) was studied. The outcomes demonstrate that an increase in treatment-time decreases the electroosmosis and ion removal rate, which might be attributed to the formation of acid-base fronts in soil, except in the IEM case. Because a high pH jump and electroosmotic flow (EOF) of water were not observed within the soil specimen due to the IEM, the removal of ions was only by diffusion and electromigration. The collision of acid-base fronts produced a large voltage gradient in a narrow soil region with a reduced electric field (EF) in its remaining parts, causing a decrease in EOF and ion transport by electromigration. The results showed that higher electroosmosis was observed by using CaCl2 and EDTA; thus, the removal rate of Co2+, Na+, and Ca2+ was greater than Cl- due to higher EOF. However, for relatively low EOF, the removal of Cl- exceeded that of Co2+, Na+, and Ca2+, possibly due to a lack of EOF. In addition, the adsorption of Fe2+ in soil increased with treatment-time due to the corrosion of the anode during all EK experiments except in the case of IEM, where an anion exchange membrane (AEM) was introduced at the anode-soil interface.


Assuntos
Recuperação e Remediação Ambiental , Poluentes do Solo , Ácido Edético , Solo , Cloreto de Cálcio , Íons , Poluentes do Solo/análise
2.
Nanotechnology ; 32(34)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34015775

RESUMO

Demand for freshwater increases day by day as impurity increases due to the industrial, domestic and municipal waste in the water. Inappropriate disposal of coal fly ash (CFA) is not eco-friendly, therefore the need is to convert it into some beneficial material like zeolite. Zeolite-based composites with metal oxides show high cation interchange capacity, fast adsorption, and high efficiency for the removal of wastewater pollutants. In this research work, metal oxide along with zeolite (derived for CFA) was prepared. Metal oxide (WO3) and magnetite (Fe3O4) based zeolite composite was used adsorption enhanced photocatalytic degradation of rhodamine B dye. Ternary composite (zeolite/WO3/Fe3O4) was characterized using a scanning electron microscope, x-ray diffraction, Fourier transform infrared spectroscopy. The bandgap energy of composite was estimated using Tauc plot method from the data obtained after UV-visible spectroscopy. The behavior of composite under acidic and basic conditions was analyzed using pHpzcof the composite. Influencing parameters like pH, dye concentration, contact time, and catalyst dosage was optimized under ultraviolet irradiations (254 nm). The results show that maximum degradation was achieved with zeolite/WO3/Fe3O4composite under optimized conditions of pH = 7, catalyst dosage = 10 mg/100 ml, RhB concentration 10 ppm, and time 60 min. The first-order kinetic model was best fitted to the experimental data. RSM was used as a statistical tool to analyze the data.

3.
Phys Chem Chem Phys ; 17(5): 3704-14, 2015 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-25557285

RESUMO

Spray coating technology has demonstrated great potential in the slow release fertilizers industry. The better understanding of the key spray parameters benefits both the environment and low cost coating processes. The use of starch based materials to coat the slow release fertilizers is a new development. However, the hydraulic spray jet breakup of the non-Newtonian starchy solutions is a complex phenomenon and very little known. The aim of this research was to study the axial and radial distributions of the Sauter Mean Diameter (SMD) and velocity vectors in pulsing spray patterns of native and modified tapioca starch solutions. To meet the objective, high speed imaging and Phase Doppler Anemometry (PDA) techniques were employed to characterize the four compositions of the starch-urea-borax complex namely S0, S1, S2 and S3. The unheated solutions exhibited very high viscosities ranging from 2035 to 3030 cP. No jet breakup was seen at any stage of the nozzle operation at an injection pressure of 1-5 bar. However, at 80 °C temperature and 5 bar pressure, the viscosity was reduced to 455 to 638 cP and dense spray patterns emerged from the nozzle obscuring the PDA signals. The axial size distribution revealed a significant decrease in SMD along the spray centreline. The smallest axial SMD (51 to 79 µm) was noticed in S0 spray followed by S1, S2 and S3. Unlikely, the radial SMD in S0 spray did not vary significantly at any stage of the spray injection. This trend was attributed to the continuous growth of the surface wave instabilities on the native starch sheet. However, SMD obtained with S1, S2 and S3 varied appreciably along the radial direction. The mean velocity vector profiles followed the non-Gaussian distribution. The constant vector distributions were seen in the near nozzle regions, where the spray was in the phase of development. In far regions, the velocity vectors were poly-dispersed and a series of ups and downs were seen in the respective radial distributions.

4.
Scientifica (Cairo) ; 2024: 3318047, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38855033

RESUMO

Finding new catalysts and pyrolysis technologies for efficiently recycling wasted plastics into fuels and structured solid materials of high selectivity is the need of time. Catalytic pyrolysis is a thermochemical process that cracks the feedstock in an inert gas environment into gaseous and liquid fuels and a residue. This study is conducted on microwave-assisted catalytic recycling of wasted plastics into nanostructured carbon and hydrogen fuel using composite magnetic ferrite catalysts. The composite ferrite catalysts, namely, NiZnFe2O4, NiMgFe2O4, and MgZnFe2O4 were produced through the coprecipitation method and characterized for onward use in the microwave-assisted valorization of wasted plastics. The ferrite nanoparticles worked as a catalyst and heat susceptor for uniformly distributed energy transfer from microwaves to the feedstock at a moderate temperature of 450°C. The type of catalyst and the working parameters significantly impacted the process efficiency, gas yield, and structural properties of the carbonaceous residue. The tested process took 2-8 minutes to pulverize feedstock into gas and carbon nanotubes (CNTs), depending on the catalyst type. The NiZnFe2O4-catalyzed process produced CNTs with good structural properties and fewer impurities compared to other catalysts. The NiMgFe2O4 catalyst performed better in terms of hydrogen evolution by showing 87.5% hydrogen (H2) composition in the evolved gases. Almost 90% of extractable hydrogen from the feedstock evolved during the first 2 minutes of the reaction.

5.
Dalton Trans ; 52(19): 6343-6359, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37083039

RESUMO

Solar photocatalysis has emerged as a pollution-free and inexhaustible technique that has been extensively researched in the domains of environmental remediation and energy production. Herein, we have integrated ZnO and CdS nanoparticles through Cu as a solid-state electron mediator to design a ZnO-Cu-CdS Z-scheme heterosystem via a sol-gel route and further tested this as a photocatalyst for dye degradation, H2 evolution, and CO2 reduction. Within 60 min of visible light exposure, about 97% of methylene blue (MB) is degraded with a degradation rate constant of 0.042 min-1 for the ZnO0.45Cu0.1CdS0.45 catalyst. The MB degradation with this catalyst is 84, 21, 4.8, and 2 times as high as those of ZnO, CdS, ZnO0.5CdS0.5, and Cu0.1ZnO0.9 catalysts. The ZnO-Cu-CdS catalyst manifests an H2 evolution efficiency of 5579 µmol h-1 g-1, which is 169, 41, 3.9, and 3.5 times as high as those of ZnO, CdS, ZnO0.5CdS0.5, and Cu0.1ZnO0.9 catalysts. Using H2 as a reducing agent, the CO production rate over the ZnO0.45Cu0.1CdS0.45 catalyst reaches 770 µmol h-1 g-1, which is 3 and 1.8 times higher than those of ZnO0.5CdS0.5 and Cu0.1ZnO0.9 catalysts. Besides, the optimal CH4 production rate over ZnO0.45Cu0.1CdS0.45 reaches 890 µmol h-1 g-1. The improved photocatalytic response of the ZnO-Cu-CdS catalyst is assigned to the delayed recombination of photoexcited charge carriers through a Z-scheme charge transport mode, maintaining the photocarriers with strong redox potentials and the dual role of Cu to serve as a conductive bridge to accelerate the charge transfer rate and enhance the light absorption due to its SPR phenomenon. This research offers a promising strategy for developing binary/ternary Z-scheme heterojunction photocatalytic systems for different photocatalytic applications.

6.
Adv Colloid Interface Sci ; 311: 102830, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36592501

RESUMO

The photocatalytic technology illustrates an eco-friendly and sustainable route to overcome environmental and energy issues. The successful construction of a photocatalyst depends on four key elements: light absorption ability, the density of active sites, redox capacity, and photoinduced electron-hole recombination rate. Sincemost of intrinsic semiconductor photocatalysts cannot meet all these requirements, they are often modified to boost their photocatalytic properties. Many strategies have been adopted to design novel and efficient photocatalysts for diverse applications. Herein, we review the most efficient of these strategies and methods focused on effectively overcoming the efficiency limitations of photocatalysts to promote their large-scale application. Subsequently, a particular aim is put on the most current studies for photocatalytic applications, including CO2 reduction, N2 fixation, H2 evolution, and pollutants degradation. Finally, key challenges and future perspectives in designing and implementing semiconductor photocatalysts for large-scale applications are discussed. Therefore, it is foreseen that this review will work as a guide for future research and provides a variety of strategies to develop novel and high-performance photocatalysts for various applications.


Assuntos
Semicondutores
7.
ACS Omega ; 8(15): 14122-14130, 2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37091425

RESUMO

The rise in the production of plastic waste has prompted the exploration of various recovery options instead of landfilling, burning, and other unethical ways of decomposing. The experimentally generated rate constants for the thermal processing of plastic waste do not yield enough liquid fuels and gases for commercial-scale usage. It is imperative to predict kinetic rate constants statistically using an appropriate combination of activation energies (E a) and frequency factors (A o) for the optimized thermal valorization of plastic waste. This approach also assists in controlling the selectivity and quantity of the pyrolysis products. A statistical kinetic model was tested to find the best combination of rate constants from different combinations of E a and A o to pyrolyze the high-density polyethylene. Two series of E a and A o were first assumed using R software. These series were then used to predict kinetic rate constants and analyze their sensitivity independently using MATLAB. The rate constants were varied from their originally predicted values during the sensitivity analysis. It was found that the rate constant k(7) dominated the other predicted rate constants where high oil and gas yields were concerned. The gas yield increased from lower to higher extreme positions in the range of 60%-74% with the first series and from 65% to 81% with the second series. The maximum oil content was found around 74% and 65% with the first series and second series, respectively.

8.
Sci Rep ; 13(1): 9057, 2023 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-37270598

RESUMO

This study performed in-situ microwave pyrolysis of plastic waste into hydrogen, liquid fuel and carbon nanotubes in the presence of Zeolite Socony Mobil ZSM-5 catalyst. In the presented microwave pyrolysis of plastics, activated carbon was used as a heat susceptor. The microwave power of 1 kW was employed to decompose high-density polyethylene (HDPE) and polypropylene (PP) wastes at moderate temperatures of 400-450 °C. The effect of plastic composition, catalyst loading and plastic type on liquid, gas and solid carbon products was quantified. This in-situ CMP reaction resulted in heavy hydrocarbons, hydrogen gas and carbon nanotubes as a solid residue. A relatively better hydrogen yield of 129.6 mmol/g as a green fuel was possible in this process. FTIR and gas chromatography analysis revealed that liquid product consisted of C13+ fraction hydrocarbons, such as alkanes, alkanes, and aromatics. TEM micrographs showed tubular-like structural morphology of the solid residue, which was identified as carbon nanotubes (CNTs) during X-ray diffraction analysis. The outer diameter of CNTs ranged from 30 to 93 nm from HDPE, 25-93 nm from PP and 30-54 nm for HDPE-PP mixure. The presented CMP process took just 2-4 min to completely pyrolyze the plastic feedstock into valuable products, leaving no polymeric residue.

9.
ACS Omega ; 8(29): 26065-26078, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37521654

RESUMO

In this study, dual S-scheme ZnIn2S4-Al2O3-ZnO (ZIS-Al-Zn) heterojunctions were produced by a facile, low cost, and rapid combustion technique. These heterojunctions accelerated the photocatalytic hydrogen production due to the multi-channel-promoted separation of photocarriers. By optimizing the content of the components, the synthesized ZIS-Al-Zn composite with 20 wt% of ZnIn2S4 and 30 wt% of Al2O3 in the ZIS-Al-Zn composite demonstrated the highest hydrogen production rate of 54.2 mmol g-1 h-1, which was nearly 11 and 8.30 times better than ZnO-Al2O3 and ZnO-ZnIn2S4 composites, respectively. The results of DRS, PL, EIS, LSV, and CV techniques showed the highest shift in the light absorption, rapid interfacial transfer, and quenched recombination of photocarriers over the ternary ZIS-Al-Zn composite than single and binary catalysts. The obtained results revealed the formation of a dual S-scheme mechanism of transfer of photocarriers in ZIS-Al-Zn heterojunctions, contributing to better hydrogen production efficiency. The optimized ZIS-Al-Zn composite also exhibited good stability and reusability.

10.
ACS Omega ; 8(21): 18891-18900, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37273618

RESUMO

Nonthermal plasma is a well-recognized environmentally advantageous method for producing green fuels. This work used different photocatalysts, including PZO, SxZO, and SxZCx for hydrogen production using an atmospheric argon coaxial dielectric barrier discharge (DBD)-based light source. The photocatalysts were produced using a sol-gel route. The DBD discharge column was filled with water, methanol, and the catalyst to run the reaction under argon plasma. The DBD reactor was operated with a 10 kV AC source to sustain plasma for water splitting. The light absorption study of the tested catalysts revealed a decrease in the band gap with an increase in the concentration of Sr and carbon nanotubes (CNTs) in the Sr/ZnO/CNTs series. The photocatalyst S25ZC2 demonstrated the lowest photoluminescence (PL) intensity, implying the most quenched recombination of charge carriers. The highest H2 evolution rate of 2760 µmol h-1 g-1 was possible with the S25ZC2 catalyst, and the lowest evolution rate of 56 µmol h-1 g-1 was observed with the PZO catalyst. The photocatalytic activity of S25ZC2 was initially high, which decreased slightly over time due to the deactivation of the photocatalyst. The photocatalytic activity decreased from 2760 to 1670 µmol h-1 g-1 at the end of the process.

11.
Heliyon ; 9(5): e16049, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37215830

RESUMO

Sensitivity analyses of rate constants for chemical kinetics of the pyrolysis reaction are essential for the efficient valorization of plastic waste into combustible liquids and gases. Finding the role of individual rate constants can provide important information on the process conditions, quality, and quantity of the pyrolysis products. The reaction temperature and time can also be reduced through these analyses. For sensitivity analysis, one possible approach is to estimate the kinetic parameters using MLRM (multiple linear regression model) in SPSS. To date, no research reports on this research gap are documented in the published literature. In this study, MLRM is applied to kinetic rate constants, which slightly differ from experimental data. The experimental and statistically predicted rate constants varied up to 200% from their original values to perform sensitivity analysis using MATLAB software. The product yield was examined after 60 min of thermal pyrolysis at a fixed temperature of 420 °C. The predicted rate constant "k(8)" with a slight difference of 0.02 and 0.04 from the experiment revealed 85% oil yield and 40% light wax after 60 min of operation. The heavy wax was missing from the products under these conditions. This rate constant can be utilized to maximize the commercial-scale extraction of liquids and light waxes from thermal pyrolysis of plastics.

12.
ACS Omega ; 8(45): 43139-43150, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-38024725

RESUMO

This study investigated a ternary CdS/TiO2/g-C3N4 heterojunction for degrading synthetic dyes and hydrogen production from aqueous media through visible light-initiated photocatalytic reactions. CdS, TiO2, and g-C3N4 were combined in different mass ratios through a simple hydrothermal method to create CdS/TiO2/g-C3N4 composite photocatalysts. The prepared heterojunction catalysts were investigated by using FTIR, XRD, EDX, SEM, and UV-visible spectroscopy analysis for their crystal structures, functional groups, elemental composition, microtopography, and optical properties. The rhodamine B dye was then degraded by using fully characterized photocatalysts. The maximum dye degradation efficiency of 99.4% was noted in these experiments. The evolution rate of hydrogen from the aqueous solution with the CdS/TiO2/g-C3N4 photocatalyst remained 2910 µmol·h-1·g-1, which is considerably higher than those of g-C3N4, CdS, CdS/g-C3N4, and g-C3N4/TiO2-catalyzed reactions. This study also proposes a photocatalytic activity mechanism for the tested ternary CdS/TiO2/g-C3N4 heterojunctions.

13.
ACS Omega ; 8(50): 47623-47634, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38144129

RESUMO

Even low concentrations of pollutants in water, particularly heavy metals, can significantly affect the ecosystem and human health. Adsorption has been determined to be one of the most effective techniques of removing pollution from wastewater among the various strategies. To remove heavy metals such as Zn2+ and Pb2+, we prepared a silica-coated CuMgFe2O4 magnetic adsorbent using sol-gel method and tested it for wastewater treatment. X-ray diffraction investigation validated the creation of cubic spinel structure, while morphological analysis showed that silica coating reduces the particle size but boosts the surface roughness of the nanoparticles and also reduces the agglomeration between particles. UV-visible spectroscopy indicates a rise in bandgap and magnetic characteristics analysis indicates low values of magnetization due to silica coating. The kinetic and isotherm parameters for heavy metal ions adsorption onto silica-coated Cu0.50Mg0.50Fe2O4 nanoparticles are calculated by applying pseudo-first-order, pseudo-second-order, Langmuir and Freundlich models. Adsorption kinetics revealed that the pseudo-second-order and Langmuir models are the best fit to explain adsorption kinetics. Synthesized adsorbent revealed 92% and 97% removal efficiencies for Zn2+ and Pb2+ ions, respectively.

14.
Curr Pharm Des ; 28(36): 2965-2983, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35466867

RESUMO

Cancer nano-therapeutics are rapidly evolving and are often used to overcome a number of concerns with traditional drug delivery methods, including non-specific drug targeting and distribution, low oral bioavailability, and poor hydrophilicity. Modern nano-based targeting techniques have been developed as a result of advances in nano vehicle engineering and materials science, which may bring people with cancer a new hope. Clinical trials have been authorized for a number of medicinal nanocarriers. Nanocarriers with the best feasible size and surface attributes have been developed to optimize biodistribution and increase blood circulation duration. Nanotherapeutics can carry preloaded active medicine towards cancerous cells by preferentially leveraging the specific physiopathology of malignancies. In contrast to passive targeting, active targeting strategies involving antigens or ligands, developed against specific tumor sites, boost the selectivity of these curative nanovehicles. Another barrier that nanoparticles may resolve or lessen is drug resistance. Multifunctional and complex nanoparticles are currently being explored and are predicted to usher in a new era of nanoparticles that will allow for more individualized and customized cancer therapy. The potential prospects and opportunities of stimuli-triggered nanosystems in therapeutic trials are also explored in this review.


Assuntos
Nanopartículas , Neoplasias , Humanos , Sistemas de Liberação de Fármacos por Nanopartículas , Distribuição Tecidual , Sistemas de Liberação de Medicamentos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Preparações Farmacêuticas , Portadores de Fármacos/uso terapêutico
15.
Materials (Basel) ; 15(10)2022 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-35629531

RESUMO

This study investigated the production of Cu2+-doped CoFe2O4 nanoparticles (CFO NPs) using a facile sol-gel technique. The impact of Cu2+ doping on the lattice parameters, morphology, optical properties, and electrical properties of CFO NPs was investigated for applications in electrical devices. The XRD analysis revealed the formation of spinel-phased crystalline structures of the specimens with no impurity phases. The average grain size, lattice constant, cell volume, and porosity were measured in the range of 4.55-7.07 nm, 8.1770-8.1097 Å, 546.7414-533.3525 Å3, and 8.77-6.93%, respectively. The SEM analysis revealed a change in morphology of the specimens with a rise in Cu2+ content. The particles started gaining a defined shape and size with a rise in Cu2+ doping. The Cu0.12Co0.88Fe2O4 NPs revealed clear grain boundaries with the least agglomeration. The energy band gap declined from 3.98 eV to 3.21 eV with a shift in Cu2+ concentration from 0.4 to 0.12. The electrical studies showed that doping a trace amount of Cu2+ improved the electrical properties of the CFO NPs without producing any structural distortions. The conductivity of the Cu2+-doped CFO NPs increased from 6.66 × 10-10 to 5.26 × 10-6 ℧ cm-1 with a rise in Cu2+ concentration. The improved structural and electrical characteristics of the prepared Cu2+-doped CFO NPs made them a suitable candidate for electrical devices, diodes, and sensor technology applications.

16.
Materials (Basel) ; 15(9)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35591559

RESUMO

The use of ZnO as a photocatalyst with a reduced recombination rate of charge carriers and maximum visible light harvesting remains a challenge for researchers. Herein, we designed and synthesized a unique La/ZnO/CNTs heterojunction system via a sol-gel method to evaluate its photocatalytic performance for hydrogen evolution. A ferrocene powder catalyst was tested for the production of CNT forests over Si/SiO2/Al2O3 substrate. A chemical vapor deposition (CVD) route was followed for the forest growth of CNTs. The La/ZnO/CNTs composite showed improved photocatalytic efficiency towards hydrogen evolution (184.8 mmol/h) in contrast to 10.2 mmol/h of pristine ZnO. The characterization results show that promoted photocatalytic activity over La/ZnO/NTs is attributed to the spatial separation of the charge carriers and extended optical absorption towards the visible light spectrum. The optimum photocatalyst shows a 16 h cycle performance for hydrogen evolution. The H2 evolution rate under visible light illumination reached 10.2 mmol/h, 145.9 mmol/h and 184.8 mmol/h over ZnO, La/ZnO and La/ZnO/CNTs, respectively. Among the prepared photocatalysts, ZnO showed the lowest H2 evolution rate due to the fast recombination of electron-hole pairs than heterojunction photocatalysts. This research paves the way for the development of ZnO and CNT-based photocatalysts with a wide optical response and reduced charge carrier recombinations.

17.
Nanomaterials (Basel) ; 12(12)2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35745460

RESUMO

Zinc oxide (ZnO) nanoparticles were loaded over non-thermal plasma (P1) and citric acid (P2)-functionalized cotton fabrics using a room temperature sonification process. The cotton samples were pretreated with dielectric barrier discharge (DBD) plasma and citric acid to introduce some reactive moieties on the fabric to enhance the adhesion power of ZnO nanoparticles with an average particle size of 41 nm. The nanoparticles were dispersed homogeneously on the surface of the P1 sample, which enhanced the antibacterial, UV protection and photocatalytic self-cleaning characteristics of ZnO-loaded fabric. The self-cleaning efficiency of P1 and P2 samples was measured to be about 77% and 63%, respectively. The inhibition zones of 5.5 mm and 5.4 mm were produced by sample P1 against E. coli and S. aureusbacteria, respectively, which were slightly higher than the inhibition zones produced by sample P2. The inhibition zone of the samples roughly decreased by 17% after performing 10 wash cycles. The unloaded cotton fabric had a UPF value of 70.02 units and blocking percentage of 70.92% and 76.54% for UVA and UVB radiations, respectively. The UVA-blocking capacity of samples P1 and P2 was 95.27% and 91.22, respectively. Similarly, the UVB blocking capacity was 94.11% and 92.65%, respectively. The pre-coating plasma treatment was found to be helpful in improving the UV-blocking ability of ZnO-loaded cotton fabric.

18.
Materials (Basel) ; 15(13)2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35806682

RESUMO

The development of cost-effective co-catalysts of high photocatalytic activity and recyclability is still a challenge in the energy transformation domain. In this study, 0D/2D Schottky heterojunctions, consisting of 0D ZnO and 2D Ti3C2, were successfully synthesized by the electrostatic self-assembling of ZnO nanoparticles on Ti3C2 nanosheets. In constructing these heterojunctions, Ti3C2 nanosheets acted as a co-catalyst for enhancing the transfer of excitons and their separation to support the photocatalytic response of ZnO. The as-prepared ZnO/Ti3C2 composites demonstrate an abbreviated charge transit channel, a huge interfacial contact area and the interfacial electrons' transport potential. The extended optical response and large reactive area of the ZnO/Ti3C2 composite promoted the formation of excitons and reactive sites on the photocatalyst's surface. The ZnO/Ti3C2 Schottky heterojunction showed significantly high photocatalytic activity for hydrogen production from a water-ethanol solution under the light illumination in the visible region. The hydrogen evolution overoptimized the ZnO/Ti3C2 composition with 30 wt.% of Ti3C2, which was eight times higher than the pristine ZnO. These findings can be helpful in developing 0D/2D heterojunction systems for photocatalytic applications by utilizing Ti3C2 as a low-cost co-catalyst.

19.
Assay Drug Dev Technol ; 20(5): 191-210, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35852823

RESUMO

Combination therapy has become much more effective in treating cancer because it produces combinatorial anticancer results, lowers specific drug-related toxicities, and inhibits multidrug resistivity through several modes of action. Combined drug delivery (CDD) to cancerous tissues, primarily based on nanotechnology, has developed as a viable method in recent years, surpassing various biomedical, biophysical, and biological obstacles that the body erects to prevent antitumor drugs from reaching their target tissues. In a combined strategy, the prolonged, regulated, and targeted administration of chemotherapeutic medicines improves therapeutic anticancer benefits while reducing drug-related adverse effects. CDD systems have several advantages over traditional drug systems, such as improved solubility, higher permeability for traveling through biomembranes, a significantly longer half-life to expand the treatment time, and low cytotoxicity. CDDs are mostly used to treat neurological, cardiovascular, neoplastic, infectious, and inflammatory diseases. Many CDDs are designed to enhance hydrophilicity to improve transportation inside or across biomembranes, particularly the cornea and skin. CDDs could be delivered to particular cells, organs, or tissues, resulting in increased bioavailability. The most widely utilized nanocarriers for CDDs of anticancer medicines are summarized in this review. This study also covers the chemical or enzymatic decomposition of CDDs and their bioactivity and pharmacokinetics. Additional clinical trials will enhance the usefulness of CDDs in treating drug-resistant tumors.


Assuntos
Antineoplásicos , Neoplasias , Antineoplásicos/química , Antineoplásicos/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Humanos , Nanotecnologia , Neoplasias/tratamento farmacológico , Preparações Farmacêuticas
20.
Materials (Basel) ; 15(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35683124

RESUMO

An environmentally friendly non-thermal DC plasma reduction route was adopted to reduce Ag+ ions at the plasma−liquid interface into silver nanoparticles (AgNPs) under statistically optimized conditions for biological and photocatalytic applications. The efficiency and reactivity of AgNPs were improved by statistically optimizing the reaction parameters with a Box−Behnken Design (BBD). The size of the AgNPs was chosen as a statistical response parameter, while the concentration of the stabilizer, the concentration of the silver salt, and the plasma reaction time were chosen as independent factors. The optimized parameters for the plasma production of AgNPs were estimated using a response surface methodology and a significant model p < 0.05. The AgNPs, prepared under optimized conditions, were characterized and then tested for their antibacterial, antioxidant, and photocatalytic potentials. The optimal conditions for these three activities were 3 mM of stabilizing agent, 5 mM of AgNO3, and 30 min of reaction time. Having particles size of 19 to 37 nm under optimized conditions, the AgNPs revealed a 82.3% degradation of methyl orange dye under UV light irradiation. The antibacterial response of the optimized AgNPs against S. aureus and E. coli strains revealed inhabitation zones of 15 mm and 12 mm, respectively, which demonstrate an antioxidant activity of 81.2%.

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