ACS Omega
October 2024
Well-dispersed Au and Ag nanoparticles (NPs) have been immobilized on a zinc imidazolate metal-organic framework, Zn(mim), using the "one-pot" method and tested as catalysts in ammonia borane hydrolysis. The AuNPs@Zn(mim) and AgNPs@Zn(mim) materials were characterized by FTIR, XRD, ICP-OES, TGA, BET, SEM, and TEM. The AgNPs@Zn(mim) catalyst showed a high yield (98.
View Article and Find Full Text PDFIn recent years, heterogeneous photocatalysis has emerged as a promising alternative for the treatment of organic pollutants. This technique offers several advantages, such as low cost and ease of operation. However, finding a semiconductor material that is both operationally viable and highly active under solar irradiation remains a challenge, often requiring materials of nanometric size.
View Article and Find Full Text PDFHerein, we report the efficient photocatalytic degradation of the diclofenac drug using the ZnPrAlO photocatalyst [x, y] = (0.00, 0.00), (0.
View Article and Find Full Text PDFThis work adopted a green synthesis route using cashew tree gum as a mediating agent to obtain Ni-doped ZnO nanoparticles through the sol-gel method. Structural analysis confirmed the formation of the hexagonal wurtzite phase and distortions in the crystal lattice due to the inclusion of Ni cations, which increased the average crystallite size from 61.9 nm to 81.
View Article and Find Full Text PDFIn this work, a ZnO hemisphere-like structure co-doped with Er and Cr was obtained by the co-precipitation method for photocatalytic applications. The dopant's effect on the ZnO lattice was investigated using X-ray diffraction, Raman, photoluminescence, UV-Vis and scanning electron microscopy/energy dispersive spectroscopy techniques. The photocatalytic response of the material was analyzed using methylene blue (MB) as the model pollutant under UV irradiation.
View Article and Find Full Text PDFCurr Drug Discov Technol
March 2023
Aims And Background: Natural preservatives are a viable alternative to replace chemical preservatives that have potential toxicity and carcinogenic effects.
Objective: To prove the effectiveness in increasing the microbiological stability of Minas Frescal cheese with the addition of a bacteriocin obtained from Latilactobacillus sakei as a natural preservative.
Methods: A new broad-spectrum bacteriocin was evaluated for its functional activity in vitro and in situ when applied in the formulation of Minas Frescal cheese.
TiO/Karaya composite was synthesized by the sol-gel method for the photoinactivation of pathogens. This is the first time that we have reported this composite for an antimicrobial approach. The structure, morphology, and optical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-rays (EDS), Fourier transform infrared spectroscopy (FTIR), and diffuse reflectance, and the surface area was characterized by the BET method.
View Article and Find Full Text PDFFood Chem
July 2022
Matrix complexity of fruit juices and their low antimony level requires sensitive, cost-effective instruments, time-consuming and error-prone sample pretreatment methods. Therefore, a flow-batch procedure (HG-FBA-AFS) was developed for the fast and sensitive determination of total inorganic Sb in grape juice samples by hydride generation atomic fluorescence spectrometry. The sample pretreatment, pre-reduction and stibine formation steps run through the mixing chamber.
View Article and Find Full Text PDFIbuprofen (IBU) is one of the most-sold anti-inflammatory drugs in the world, and its residues can reach aquatic systems, causing serious health and environmental problems. Strategies are used to improve the photocatalytic activity of zinc oxide (ZnO), and thosethat involvethe inclusion of metalhave received special attention. The aim of this work was to investigate the influence of the parameters and toxicity of a photoproduct using zinc oxide that contains cerium (ZnO-Ce) for the photodegradation of ibuprofen.
View Article and Find Full Text PDFUltrason Sonochem
November 2021
An ultrasonic reactor (UR) was developed and coupled to a digital movie-based flow-batch analyzer (DM-FBA) for the ultrasonic-assisted extraction (UAE) and fast determination of catalase and lipase activities in bovine and poultry livers. The lab-made UR mainly consisted of a borosilicate glass container and a piezoelectric disc. The DM-FBA mainly consisted of a webcam, an ultrasonic actuator controller, a peristaltic pump, six solenoid valves, a valve driver, a mixing chamber, a magnetic stirrer, an Arduino Mega 2560, and a personal computer.
View Article and Find Full Text PDFThis paper aimed to develop a new photocatalytic reactor design with a rotary tree branch structure for wastewater treatment in the textile industry. The brass sheet calcined at 500 °C (B500) was used as the photocatalyst and as a substrate for ZnO nanoparticle immobilization (B500ZnO). The photoreactor performance was evaluated toward the photodegradation of an aqueous solution of Reactive Black 5 dye (AS-RB5), raw wastewater (RW), and treated wastewater (TW).
View Article and Find Full Text PDFThis work describes a 3D-printed robotic system named RSAWA (robotic system for automatic water analysis) for fully automated water analysis. RSAWA consists of a robotic arm coupled to a syringe pump, temperature and conductivity sensors, a low-cost webcam as colorimetric detector, and a 96-well microplate placed on a 3D-printed platform. The robotic system is controlled by software and it performs all analytical procedures.
View Article and Find Full Text PDFFlowers-like ZnO structures were synthesized using Arabic Gum (AGZnO) or Karaya Gum (KGZnO). The AGZnO and KGZnO were characterized by X-ray diffractometry, Fourier Transformed Infrared, Scanning Electron Microscopy, Photoluminescence, nitrogen adsorption/desorption and diffuse reflectance techniques. The materials were tested in the discoloration of Methylene Blue (MB) dye under visible light and scavenger studies were also performed.
View Article and Find Full Text PDFNovel green photocatalysts based on ZnO in the presence of arabic gum (AGZ) or karaya gum (KGZ) were synthesized by a sol-gel method for photocatalytic performance. The materials were characterized by XRD, FTIR spectroscopy, SEM, nitrogen adsorption/desorption, and PL and diffuse reflectance spectroscopy. Photocatalytic test was performed using methylene blue (MB) dye as the target pollutant under visible light.
View Article and Find Full Text PDFIn this paper, a flow-batch analysis (FBA) system, hydride generation (HG), and atomic fluorescence spectrometry (AFS) are coupled for the first time to develop a fast and sensitive FBA-HG-AFS method for automated inorganic antimony speciation in waters, whether from the sea, mineral water, tap water, or lakes. Unlike previous automated flow methods that use confluent fluids and complex devices, the main advantage of the proposed FBA-HG-AFS method is an innovative use of a simple laboratory made flow-batch chamber to simultaneously perform mixing, homogenization, reactions, antimony hydride formation, and gas-liquid separation. The FBA-HG-AFS method was optimized using two-level full factorial and Box-Behnken designs, and validated on the basis of real repeated measurements and analysis of variance, yielding a satisfactory working range (100-2000 ng L), precision (RSD = 4%), sensitivity, and limit of detection (6 ng L) for the water samples analyzed.
View Article and Find Full Text PDFTalanta
February 2018
A lab-made magnetic-mechanical robotic (MMR) system coupled to a flow-batch analyzer (FBA) for magnetic nanoparticles solid phase extraction (MSPE) is presented. As an illustrative application, an NMR-FBA couple was connected to a graphite furnace atomic absorption spectrometer (GFAAS) for quantification of trace cadmium in edible oils. Factors affecting MSPE, such as the amount of adsorbent, the type, concentration and volume of the eluent and elution time were studied.
View Article and Find Full Text PDFHydrogen fuels generated by water splitting using a photocatalyst and solar irradiation are currently gaining the strength to diversify the world energy matrix in a green way. CdS quantum dots have revealed a hydrogen generation improvement when added to TiO2 materials under visible-light irradiation. In the present paper, we investigated the performance of TiO2 nanotubes coupled with CdS quantum dots, by a molecular bifunctional linker, on photocatalytic hydrogen generation.
View Article and Find Full Text PDFThis study proposes the use of digital movies (DMs) in a flow-batch analyzer (FBA) to perform automatic, fast and accurate titrations. The term used for this process is "Digital movie-based on automatic titrations" (DMB-AT). A webcam records the DM during the addition of the titrant to the mixing chamber (MC).
View Article and Find Full Text PDFCp-Ti is the most common material used for dental implants, but its elastic modulus is around five times higher than that of bone. Recently, promising alloys that add Nb, Ta, Zr and Mo to Ti have been developed. The mechanical properties of these alloys are directly related to its microstructure and the presence of interstitial elements, such as oxygen, carbon, nitrogen and hydrogen.
View Article and Find Full Text PDFDensity functional theory (DFT) was used to examine the interaction between molecular oxygen (O₂) and macrocyclic iron complexes of the type FeN₄ during the formation of FeN₄--O₂ adducts. In order to understand how this interaction is affected by different macrocyclic ligands, O₂ was bonded to iron-tetraaza[14]annulene (FeTAA), iron-tetramethyl-tetraaza[14]annulene (FeTMTAA), iron-hexamethyl-tetraaza[14]annulene (FeHMTAA), iron dibenzotetraaza[14]annulene (FeDBTAA), and two iron-tetramethyl-dibenzotetraaza[14]annulene complexes (FeTMDBTAA1, FeTMDBTAA2). The ground state for FeN₄-O₂ adducts was the open-shell singlet.
View Article and Find Full Text PDFIn this study, a micro-flow-batch analyzer (μFBA) with solenoid micro-pumps for the photometric determination of iodate in table salt is described. The method is based on the reaction of iodate with iodide to form molecular iodine followed by the reaction with N,N-diethyl-p-phenylenediamine (DPD). The analytical signal was measured at 520 nm using a green LED integrated into the μFBA built in the urethane-acrylate resin.
View Article and Find Full Text PDFA method for the determination of phosphorus in mineralized biodiesel using a micro-flow-batch analyzer (μFBA) with solenoid micro-pumps was proposed. The samples were mineralized using an ashing procedure at 550 °C followed by dissolution of the residue. The determination of phosphorus was performed by employing the well-known molybdenum blue method.
View Article and Find Full Text PDFThis work introduces the monosegmented flow-batch (MSFB) analysis concept. This system combines favourable characteristics of both flow-batch and the monosegmented analysers, allowing use of the flow-batch system for slow reaction kinetics without impairing sensitivity or sampling throughput. The MSFB was evaluated during spectrophotometric determination of boron in plant extracts, which is a method that involves a slow reaction between boron and azomethine-H.
View Article and Find Full Text PDFThe principal thermodynamic advantages of using microemulsions over standard emulsions for flow metal analysis are the greatly increased analyte stability and emulsive homogeneity that improve both the ease of sample preparation, and the analytical result. In this study a piston propelled flow-batch analyzer (PFBA) for the determination of Cu, Cr and Pb in gasoline and naphtha by graphite furnace atomic absorption spectrometry (GF AAS) was explored. Investigative phase modeling for low dilution was conducted both for gasoline and naphtha microemulsions.
View Article and Find Full Text PDFJ Pharm Biomed Anal
March 2012
A flow injection photometric system that exploits Schlieren signals for analytical measurement is described. The system was designed to be used as a new strategy for determining the contents of sodium chloride, potassium chloride and glucose, each respectively in injectable drugs. The proposed methodology was based on the difference between the refractive indices of the sample zone and of the carrier stream.
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