Characterization Techniques Research Articles

Enhanced adsorption, anticancer and antibacterial potentials of Pontederia crassipes L. extract mediated ecofriendly synthesized ZnO/biochar nanohybrid

This current study presents a green synthesis approach of ZnO, biochar and ZnO/biochar nanostructures using leaves of Pontederia crassipes L. The green fabricated nanomaterials were investigated using different characterization techniques, including as XRD, UV–Vis, TEM, FE-SEM, EDX, BET/BJH, and FTIR. The fabricated nanomaterials were well crystallized with an average crystallite size of 40 nm (ZnO), 43 nm (biochar), and 48 nm (ZnO/biochar). A coomassie brilliant blue G250 (CBB) and methylene blue (MB) removal study was conducted to optimizing (optimize) the influence of operating factors on the adsorption efficiency. Employing a ZnO/biochar 98 % and 99 % adsorption efficiencies were reached in an optimum condition for CCB and MB, respectively. Adopting ZnO/biochar heterostructure as an anticancer for MCF-7 human breast cancer cells was also evaluated. The MTT assay revealed that ZnO/biochar samples exhibit a promise in vitro cytotoxic efficacy against the MCF-7 cell line with IC50 being 79.82 μg /mL. In addition, antimicrobial activity of ZnO/biochar nanoparticles was evaluated on Gram-negative and Gram-positive bacteria. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were used as test microorganisms. The results revealed that the ZnO/biochar possesses an antibacterial inhibition zone of 11 and 9 mm on E. coli, and S. aureus, respectively.

Spin-Electrochemistry of Transition Metal Oxides for Energy Storage: Concepts, Advances and Perspectives.

Developing high-capacity and cyclically stable transition metal (TM)-based electrode materials for energy storage devices, such as aqueous ion energy storage systems, is crucial for addressing the growing issue of energy scarcity. The spin state, or spin configuration of the d-electrons, plays a vital role in the electrochemical energy storage performance of these materials. However, there has been a lack of systematic descriptions regarding the role of spin configurations in electrochemical energy storage to date. This review aims to elucidate the advantages of controlling the spin states of metal centers to enhance energy storage performance and highlights recent progress in employing spin state regulation in electrochemical energy storage. Additionally, it covers the various characterization techniques used to determine spin states. Finally, we discuss the future prospects and challenges within this emerging field, with the aim of accelerating the development of spin-based electrochemical energy storage technologies. This review also seeks to provide clear and reliable directions for the design and preparation of novel energy storage materials.

Study on the methanol aqueous phase reforming performances over Pt/CeO2 catalysts: The effect of CeO2 morphologies and oxygen vacancies

CeO2-supported catalysts have been extensively studied for hydrogen production via aqueous phase reforming of methanol (APRM) although several issues remain unclear, such as the influence of different morphologies on catalytic performance and the role of their oxygen vacancies in enhancing hydrogen yield. In this study, CeO2 with three distinct morphologies were synthesized, and platinum was loaded onto these supports via a photoreduction method to produce highly-dispersed catalysts designated as Pt/CeO2-R (rod-shaped), Pt/CeO2-C (cubic) and Pt/CeO2-O (octahedral) respectively. A series of APRM experiments suggested that Pt/CeO2-R exhibited the highest hydrogen production capacity (146.2 mmol-H2/gcat.). This superior performance is likely to attribute to the highly-dispersed Pt on the rod-shaped CeO2 support, which provides a substantial number of active metal sites, promoting the efficient adsorption and activation of methanol throughout the process. The anchoring effect of platinum on support surface and redox properties of Pt species were also thoroughly investigated with various characterization techniques. Further analysis revealed a strong correlation between turnover frequency (TOF) and the presence of oxygen vacancies on Pt/CeO2. Notably, abundant oxygen vacancies on catalyst enhanced substrate adsorption and the rapid conversion of CO* intermediates adsorbed on platinum, which accelerated the water-gas shift (WGS) reaction through a faster redox pathway, leading to higher hydrogen production with low CO selectivity.

Stacking-order independent inter-layer charge transfer in MBE-grown MoSe2 and WSe2 heterostructures

MoSe2/WSe2 heterostructure is gaining significant research interest due to its unique electrical and optical properties, making them suitable for various advanced applications. This work focuses on inter-layer charge transfer effects on MBE-grown MoSe2 and WSe2 heterostructures. Bilayer (BL)-MoSe2/BL-WSe2 and BL-WSe2/BL-MoSe2 have been grown over a c-plane sapphire substrate using molecular beam epitaxy (MBE). Different characterization techniques including Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and reflection high-energy electron diffraction (RHEED) confirm the phase, composition, surface morphology, and crystalline quality of the films, respectively. The band diagram using Ultraviolet-visible (UV-Vis) spectroscopy, XPS core level spectra, XPS valence band spectra and surface work function shows that individual MoSe2 and WSe2 BLs grown over c-plane sapphire are n-type and p-type semiconductors, respectively. This study shows that when the individual BLs form MoSe2/WSe2 and WSe2/MoSe2 heterostructures, a unidirectional electron transfer occurs from the WSe2 to MoSe2, which is independent of WSe2 and MoSe2 stacking order. As a result, the Fermi level position changes for both the materials in their heterostructures, which makes MoSe2 more n-type semiconductor and WSe2 more p-type semiconductor. MoSe2/WSe2 and WSe2/MoSe2 heterostructures show a type II band alignment with a conduction band offset of 0.57 eV and a valance band offset of 0.51 eV These findings contribute to a deeper understanding of the interfacial charge transfer effects and design of MoSe2 and WSe2 heterostructures for potential device applications.

The investigation of highly efficient chlorinated hydrocarbons removal based on metal nanoparticles carbonaceous synthetic particles: The degradation behavior and selective transformation mechanism

Overconsumption in industrial manufacturing has led to critical emissions of chloroalkanes, posing a significant environmental threat. In this study, the innovative biochar (BC) particles containing nanocrystalline: NZVI, Fe/Pd, Fe/Ni were prepared by impregnation-liquid phase reduction using the pyrolysis of coconut husk as precursors to explore the degradation capabilities of chloroform (CF) via orthogonal experiment. The results indicated that when the pH value was 3, the temperature was 20 ℃, and the reaction time was 60 min, the CF removal efficiency of Fe/Ni-BC reached 80.38 ± 2.08 %, outperforming all other tested synthetic particles. Advanced characterization techniques showed that the abundant dispersed metallic nanoparticle sites would refresh the surface crystal morphology, improve the adsorption enrichment ability of biochar, enhance electron transfer capacity of synthetic particles, and further participate in reductive dechlorination by inducing an electrophilic attack of active hydrogen. Theoretical calculations verified that hydrogen activation and CF facile adsorption would be easily achieved after the introduction of metal nanoparticles, profiting from the multiple synergistic effects between special π-delocalized bond of biochar in carbon layer and multiple nanoparticles docking sites, and thus enhancing the specific CF catalytic selectivity of Fe/Ni as the active center. Collectively, the CF degradation on Fe/Ni-BC was a complex chemisorption process along with reductive hydrogenation decomposition, which achieved the parent CF reduction and promoted the conversion of the low-chlorinated benign products. These findings offer new insights into the developed multifunctional BC and their comprehensive assessment of CF sewage remediation.

Trametes versicolor laccase-derived silver nanoparticles: Green synthesis, structural characterization and multifunctional biological properties

Isolated enzymes serve as advantageous platforms for the fabrication of nanomaterials. The objective of this study was to fabricate silver nanoparticles (AgNPs) incorporated with Trametes versicolor laccase and evaluate their diverse biological properties. The AgNPs fabricated through laccase-mediated methods were characterized using various characterization techniques including UV–visible (UV–vis) spectroscopy, Energy-dispersive X-ray (EDX) spectroscopy, Dynamic light scattering (DLS) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and Field emission scanning electron microscopy (FE-SEM). The results showed that the laccase-incorporated AgNPs were spherical in shape with a Z-average diameter of 19.40 nm and a zeta potential of −19.2 mV. The AgNPs exhibited significant dose-dependent in vitro α-amylase, urease, and DPPH free radical inhibitory activities, with maximum inhibitions of 83.49 ± 1.06 %, 68.95 ± 3.60 %, and 67.36 ± 3.40 %, respectively, at a concentration of 1000 μg mL−1. Furthermore, the intrinsic pathway-mediated anticoagulant activity of the fabricated AgNPs was confirmed through the activated partial thromboplastin time (aPTT) assay, which serves as a global coagulation assay. Additionally, the laccase-incorporated AgNPs demonstrated antibacterial properties against both standard gram-positive strains of Staphylococcus epidermidis and Streptococcus mutans, with minimum inhibitory concentration (MIC) values of 2 and 4 μg mL−1, and minimum bactericidal concentration (MBC) values of 16 and 16 μg mL−1, respectively. The dose-dependent antibacterial performance of the AgNPs against both bacterial populations was also confirmed through flow cytometry. Moreover, the AgNPs exhibited 61.53 ± 3.17 % and 63.03 ± 1.44 % biofilm degradation against S. epidermidis and S. mutans, respectively, at the maximum tested concentration (20∗MIC).

Modifying metal ion ratios in nickel-aluminum layered double hydroxide/reduced graphene oxide composites for selective electrochemical detection of antibiotics

Antimicrobial resistance (AMR) is a global threat that occurs as microorganisms evolve to resist antibiotic (ATB) overuse. To monitor this overuse, inexpensive, affordable, and adaptable sensors are required. While electrochemical sensors are promising, they cannot often distinguish between overlapping electrochemical interactions from multiple ATBs, resulting in poor analyte selectivity. To overcome this challenge, we design electrocatalysts consisting of nickel aluminum layered double hydroxides (NiAl-LDH) and their composites by altering the metal ion ratio to adjust the surface properties and selectivity of sensors. Synthesis of LDH and its graphene oxide (GO) composites is conducted using a low-temperature hydrothermal method. The prepared materials are characterized using various morphological and structural characterization techniques. Electrochemical characterization confirms that tuning the metal ion ratio allows sensors to differentiate between electrochemical reactions, improving the selective detection of amoxicillin and tetracycline from their mixtures. Addition of graphene oxide also enhances sensing capabilities. The optimized sensor has sensitivities of 137.6 nA µM−1 cm−2 and 161.4 nA µM−1 cm−2, and lower detection limits of 4.3 nM and 3.6 nM, respectively, for amoxicillin (Amx) and tetracycline (TC). Interferents have no significant effect on the detection of relatively low concentrations (10 µM) of the two ATBs. The electrodes can also detect the two analytes in tap water samples. This sensor methodology can potentially improve environmental antibiotic detection to mitigate the risk of antimicrobial resistance.

A novel deep learning‐based technique for efficient characterization of engineered cementitious composites cracks for durability assessment

AbstractEngineered Cementitious Composites also known as Strain‐hardening cementitious composites (SHCCs) has unique cracking patterns like cracks that have tiny widths and showcase high density. All of this makes it difficult and laborious to compute crack parameters from crack patterns. Unfortunately, this is an essential part of assessing durability and micromechanical modeling. SHSnet is developed to perform end‐to‐end semantic segmentation of SHCC cracks. SHSnet is efficient, attention based deep encoder‐decoder network with large receptive field. Loss function based on Tversky function were used for training the model. SHSnet with loss function shows promising result with mPrecision, mF1Score and mIoU of 0.87, 0.84 and 0.83 respectively for complex SHCC cracks while requiring at least an order of fewer computational parameters than those in the literature. An image processing unit is then used to estimate the width, number, and length of the cracks from the segmentation mask. Test results show that the computed crack parameters with SHSnet are exactly the same as that computed with an optical microscope but require ~100× less time. Results demonstrate that SHSnet works equally well in SHCCs with different surface textures, crack density, and widths; the final result was far superior to a conventional technique. This technique also shows promising results in an automatic evaluation of crack parameters relevant to durability and visualizing crack patterns even in the presence of artifacts during progressive testing. The results also demonstrate the necessity to accurately and densely calculate crack length and maximum crack width; else the durability results are expected to be significantly more conservative than the actual value.

Characterization of Nano Calcium Carbonate Extracted from Eggshells

Organic waste, especially eggshells, represents a valuable resource for the synthesis of calcium carbonate nanoparticles, which have significant industrial and medical applications. This study describes the methodology for converting eggshells into calcium carbonate nanoparticles through heat treatment and nano milling processes. Advanced characterization techniques, including TEM, SEM, and AFM, were used to analyze the morphology and structure of the synthesized nanoparticles. The particles were found to be of nanometer dimensions, with a size of around 150 nm and a distinctive spherical shape, as shown in the TEM images. SEM images showed that the surface of calcium carbonate nanoparticles synthesized from eggshells is smooth, crystalline, and spherical or nearly spherical. FTIR analysis revealed the presence of distinct functional groups for calcium carbonate, with peaks at 713–868 cm⁻¹, consistent with previous studies. The results show that nanoparticles manufactured from calcium carbonate possess unique properties that enhance their applicability in various fields, and promote sustainability and environmental preservation.

Functionalized cellulose nanocrystals for enhanced wood protection: Synthesis, characterization, and performance

This study developed eco-friendly protective materials for wood preservation, focusing on enhancing fungal decay resistance, insect damage prevention, and improving physical and mechanical properties. The research examined the penetration of cellulose nanocrystals (CNCs) and their functionalized compounds into wood tissue, evaluating their impact on poplar wood. Methodology included optimizing CNC production through acid hydrolysis, testing various temperature and time combinations. CNCs were then functionalized with Poly(dimethylsiloxane)-bis(3-aminopropyl) terminated (PDMS-NH), copper hydroxide, zinc oxide, and silver nanoparticles. Characterization techniques such as AFM, TEM, ESEM, XRD, FTIR, and μ-Raman spectroscopy analyzed CNCs and their derivatives. Wood samples were impregnated with CNCs and functionalized CNCs using pressure and vacuum treatments, then tested for weight gain, durability against white rot (Trametes versicolor) and brown rot (Coniophora puteana) fungi, resistance to insect attack (Trichoferus holosericeus), leaching resistance, and mechanical properties. Key findings included successful optimization of CNC production and functionalization, improved resistance against decay fungi (especially with CNC3/Cu treatment), elevating durability classification from "non-durable" to "low durability". However, treatments showed limited effectiveness against insect infestation. Leaching resistance varied among treatments, with CNC3/PDMS-NH performing best. Mechanical properties, particularly modulus of elasticity, improved significantly with CNC3 impregnation, especially in less degraded wood samples. The study contributes to eco-friendly wood protection systems development, demonstrating functionalized CNCs' potential to enhance wood durability and mechanical properties. Further research is needed to improve insect resistance and optimize the leaching performance of CNC-based treatments, paving the way for more sustainable wood preservation methods.

Development of surface-texturized black silicon through metal-assisted chemical etching and its application in the thermophotovoltaic field: a review and recommendation

Abstract The Shockley-Queisser limit poses a significant challenge in solar technology research, limiting the theoretical efficiency to around 30%. Thermophotovoltaic (TPV) systems have emerged as a solution by incorporating a thermal absorber in traditional solar cell setups to achieve total efficiency beyond the limits. The efficiency of the overall system heavily depends on the performance and quality of the thermal absorber, which absorbs photons from the heat source and transfers them to the TPV cell. However, complex and expensive fabrication processes have hindered widespread adoption of TPV technology. The well-established metal assisted chemical etching (MACE) method could be the best choice to mitigate these as it is a cost-effective, scalable, and mass-production-friendly process, which is widely used for surface texturization, creating nanostructures like nanopores, pyramids, and nanowires. MACE
technique is also suitable for producing highly efficient silicon-based thermal absorbers with over 90% absorption rate, which can contribute to increased total conversion efficiency. However, it does not come without challenges such as maintaining control over the etch rate in order to achieve uniformity. This paper comprehensively reviews the utilization of MACE for fabricating silicon-based thermal absorbers in TPV systems with the range of effective wavelengths of 600 – 2000 nm which corresponds to the energy level of 0.55 – 1.85 eV. The advantages and challenges of MACE, along with characterization techniques, are extensively discussed. By providing valuable insights, this paper aims to support researchers interested in advancing TPV technology.

Facile Synthesis of Fluorescent Carbon Quantum Dots with High Product Yield Using a Solid-Phase Strategy.

The liquid-phase method is the most commonly utilized strategy for synthesizing fluorescent carbon quantum dots (CQDs). However, the liquid-phase synthesis of CQDs faces challenges such as low yield, complex purification, and the use of toxic solvents, which limit large-scale production and practical applications. In this study, fluorescent CQDs with a high product yield of 78% were synthesized using glucose as a carbon source through a green and facile one-step solid-phase approach, without solvents or post-treatment. A systematic study of the structure and fluorescence properties of the synthesized CQDs was conducted using various characterization techniques. The results indicated that the mean size of obtained CQDs was 4.1 nm, and that their surface had abundant oxygen-containing functional groups, resulting in favorable water solubility. The synthesized CQDs exhibited excitation-dependent fluorescence, with optimal excitation and emission wavelengths at 358 and 455 nm, respectively. Additionally, the CQDs solution showed bright blue fluorescence under 365 nm UV light, with a quantum yield of 6.21% and a fluorescence lifetime of 3.02 ns. This study offers valuable insights into the green and efficient synthesis of fluorescent CQDs powder.

Structural-modulated substrate of MXene for surface-enhanced Raman scattering sensing.

The distinctive structure of MXene offers exceptional electron transport properties, abundant surface chemistry, and robust mechanical attributes, thereby bestowing it with remarkable advantages and promising prospects in the realm of surface-enhanced Raman scattering (SERS). This review comprehensively outlines the evolution, synthesis methodologies, and characterization techniques employed for MXene-based SERS substrates. It delves into the intricacies of its SERS enhancement mechanism, substrate variants, and performance metrics, alongside showcasing its diverse applications spanning molecular detection, biosensing, and environmental monitoring. Furthermore, it endeavors to pinpoint the research bottlenecks and chart the future research trajectories for MXene-based SERS substrates.

A perspective on structured light's applications

For the past few decades, structured light has been gaining popularity across various research fields. Its fascinating properties have been exploited for both previously unforeseen and established applications from new perspectives. Crucial to this is the several techniques that have been proposed for both their generation and characterization. On the one hand, the former has been boosted by the invention of computer-controlled devices, which combined with a few optical components allow flexible and complete control of the spatial and polarization degrees of freedom on light, thus enabling a plethora of proof-of-principle experiments for novel and old applications. On the other hand, characterizing light beams is important not only for gaining better insights into light's properties but also for potentially being used as metrics. In this perspective, we thus offer our take on a few key applied research fields where structured light is particularly promising, as well as some pivotal generation and characterization techniques. In addition, we share our vision of where we believe structured light's applications are moving toward.

Predictive Modeling and Adsorption Behavior, Kinetics, and Thermodynamic Studies of <i>Anthocleista grandiflora </i>Leaf Extract for Corrosion Inhibition of Carbon Steel in Seawater

This study investigates the corrosion inhibition performance of Anthocleista grandiflora leaf (AGL) extract on carbon steel in seawater, considering the effects of temperature, immersion time, and inhibitor concentration. Predictive modeling, adsorption behavior, and the kinetics and thermodynamics of the inhibition process were examined. The weight loss technique,characterization techniques combined with response surface methodology (RSM), revealed that the AGL extract follows the Langmuir adsorption model, exhibiting physical adsorption with ΔG values between −16.24 to −15.49kJ/mol, indicating spontaneous and endothermic inhibition. The thermodynamic parameters entropy (−198.87 to −52.58 J/mol), enthalpy (20.42 to 53.42 kJ/mol), and activation energy (13.68 to 56.32 kJ/mol further support this. The corrosion reaction follows first-order kinetics, with the half-life decreasing as the rate constant and extract concentration increase.The SEM images revealed that the AGL extract formed a protective surface layer on the mild steel, effectively preventing pitting. This protective effect became more pronounced as the concentration of the extract increased. RSM optimization identified optimal conditions for maximum inhibition efficiency (98.70%) and corrosion rate (0.058 mm/y) at 800 ppm, 303 K, and 45 days, with a prediction accuracy of 95%, making it suitable for application in the oil and gas industry.

Nickel Oxide-Impregnated Phosphated Silica Catalyst: Synthesis and Application for Ethanol Dehydration into Diethyl Ether (DEE)

The synthesis, characterization, and application of a NiO-PO4/SiO2 catalyst for ethanol dehydration to diethyl ether were successfully conducted. The sol-gel method utilized TEOS as the silica source, NaHCO3 as a template, and different phosphoric acid concentrations (1, 2, and 3 M). Calcination occurred at temperatures of 400, 500, and 600 °C. The catalyst with the highest acidity underwent impregnation with 1, 2, and 3% (w/w) nickel precursor proceeded by calcination with N2 gas. Characterization techniques included FTIR, XRD, SEM-EDX, and AAS. The application of SP 2-NiO 3% catalyst as the catalyst with the highest acidity demonstrated significant activity and selectivity in diethyl ether production at 175, 200, and 225 °C temperatures, yielding 88% conversion and 5.07% diethyl ether selectivity at its optimum temperature of 225 °C.

Exploring the cytotoxic and antioxidant properties of lanthanide-doped ZnO nanoparticles: a study with machine learning interpretation

BackgroundLanthanide-based nanomaterials offer a promising alternative for cancer therapy because of their selectivity and effectiveness, which can be modified and predicted by leveraging the improved accuracy and enhanced decision-making of machine learning (ML) modeling.MethodsIn this study, erbium (Er3+) and ytterbium (Yb3+) were used to dope zinc oxide (ZnO) nanoparticles (NPs). Various characterization techniques and biological assays were employed to investigate the physicochemical and optical properties of the (Er, Yb)-doped ZnO NPs, revealing the influence of the lanthanide elements.ResultsThe (Er, Yb)-doped ZnO NPs exhibited laminar-type morphologies, negative surface charges, and optical bandgaps that vary with the presence of Er3+ and Yb3+. The incorporation of lanthanide ions reduced the cytotoxicity activity of ZnO against HEPG-2, CACO-2, and U87 cell lines. Conversely, doping with Er3+ and Yb3+ enhanced the antioxidant activity of the ZnO against DPPH, ABTS, and H2O2 radicals. The extra tree (ET) and random forest (RF) models predicted the relevance of the characterization results vis-à-vis the cytotoxic properties of the synthesized NPs.ConclusionThis study demonstrates, for the first time, the synthesis of ZnO NPs doped with Er and Yb via a solution polymerization route. According to characterization results, it was unveiled that the effect of optical bandgap variations influenced the cytotoxic performance of the developed lanthanide-doped ZnO NPs, being the undoped ZnO NPs the most cytotoxic ones. The presence alone or in combination of Er and Yb enhanced their scavenging capacity. ML models such as ET and RF efficiently demonstrated that the concentration and cell line type are key parameters that influence the cytotoxicity of (Er, Yb)-doped ZnO NPs achieving high accuracy rates of 98.96% and 98.67%, respectively. This study expands the knowledge of lanthanides as dopants of nanomaterials for biological and medical applications and supports their potential in cancer therapy by integrating robust ML approaches.Graphical abstract

Crystallographic characterization of gypsum synthesized from marine wastes (Babylonia japonica, Olive sayana, and Conasprella bermudensis)

This study focused on the synthesis of gypsum nanocrystals using conventional wet chemical precipitation method from marine mollusks like Babylonia Japonica, Olive Sayana, and Conasprella bermudensis. Different characterization techniques like Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDX) were used to confirm the formation of the nanocrystals. XRD data assessed various structural parameters, including the dimension of the unit cell, crystallinity index, specific surface area, lattice parameters, dislocation density, and macrostrain. The Rietveld refinement study did not reveal the formation of alternate phases, and the predicted lattice parameters, Full Width at Half Maximum (FWHM), and X-ray density contradicted the actual data. The synthesized gypsum displayed crystallite dimension within the acceptable range of <200 nm, as calculated using various XRD models and equations. Additionally, the values for strain (2 × 10−4 to 4 × 10−4), stress (−1 × 107 to 2 × 107 N/m2), and energy density (2.87 × 102 to 2.16 × 103 J/m3) were also estimated for the synthesized samples. The preferential growth calculation indicateed stable phase formation of gypsum along the (0 2 0) and (0 4 0) planes. Furthermore, The study compared the properties of gypsum, including pH, conductivity, and potential difference (PD), in soil extraction and an aqueous medium.

CoWO4/Reduced Graphene Oxide Nanocomposite-Modified Screen-Printed Carbon Electrode for Enhanced Voltammetric Determination of 2,4-Dichlorophenol in Water Samples.

Water pollution with phenolic compounds is a serious environmental issue that can pose a major threat to the water sources. This pollution can come from various agricultural and industrial activities. Phenolic compounds can have detrimental effects on both human health and the environment. Therefore, it is essential to develop and improve analytical methods for determination of these compounds in the water samples. In this work, the aim was to design and develop an electrochemical sensing platform for the determination of 2,4-dichlorophenol (2,4-DCP) in water samples. In this regard, a nanocomposite consisting of CoWO4 nanoparticles (NPs) anchored on reduced graphene oxide nanosheets (rGO NSs) was prepared through a facile hydrothermal method. The formation of the CoWO4/rGO nanocomposite was confirmed via different characterization techniques. Then, the prepared CoWO4/rGO nanocomposite was used to modify the surface of a screen-printed carbon electrode (SPCE) for enhanced determination of 2,4-DCP. The good electrochemical response of the modified SPCE towards the oxidation of 2,4-DCP was observed by using cyclic voltammetry (CV) due to the good properties of CoWO4 NPs and rGO NSs along with their synergistic effects. Under optimized conditions, the CoWO4/rGO/SPCE sensor demonstrated a broad linear detection range (0.001 to 100.0 µM) and low limit of detection (LOD) (0.0007 µM) for 2,4-DCP determination. Also, the sensitivity of CoWO4/rGO/SPCE for detecting 2,4-DCP was 0.3315 µA/µM. In addition, the good recoveries for determining spiked 2,4-DCP in the water samples at the surface of CoWO4/rGO/SPCE showed its potential for determination of this compound in real samples.

Synthesis, spectroscopic characterization techniques of aromatic iminoaniline derived compound, along with the evaluation of its LNO properties using quantum chemistry

In this research work, we synthesized a Schiff base derivative, N,N-dimethyl-4-{[(4-nitrophenyl)imino]-methyl}aniline, denoted as (n1). The molecule (n1) was characterized using spectroscopic analyses, including FT-IR, NMR 1H, and 13C. Our compound (n1) is an unsaturated molecule, consisting of two benzylic rings connected by a methylimine bridge. The resulting system comprises seven alternating π bonds. At both ends of (n1) and in the para position, there are the N(CH3)2 group with a strong electron-donating effect and the NO2 group with a strong electron-accepting effect. The molecular structure of our compound prompted us to evaluate and study its properties in the field of NLO. The assessment of NLO properties is conducted by determining the Egap and employing density functional theory (DFT) quantum chemistry studies. The optical gap of (n1), measured using the Tauc method, is found to be 2.7 eV, serving as a reference value for the choice of the DFT functional in theoretical calculations. Quantum chemistry studies were carried out using Gaussian09 software, and the results were visualized with GaussView05. CAM-B3lyp functional was chosen for theoretical calculations due to its close agreement with experimental values. The studies confirm that (n1) exhibits significant NLO properties. Additionally, NBO (Natural Bond Orbital) analyses provide insight into the mechanism and trajectory of intramolecular charge transfer in (n1).