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Industrial dye effluent causes significant risks to the environment. The present study was focused on photocatalytic degradation of the dye Direct Red 28 using a ternary composite of graphitic carbon nitride, TiO2, and polyorthoanisidine (g-C3N4/TiO2/POA), prepared by in-situ oxidative polymerization o-anisidine. The synthesized composite g-C3N4/TiO2/POA properties were characterized using different analytical techniques. X-ray diffraction (XRD) results revealed the prominent pattern of TiO2 and g-C3N4 in the composite peak at 2θ° while Fourier transform infrared (FTIR) results provided the confirmation peaks for g-C3N4/TiO2/POA and POA at 1,110 cm−1 and 1,084 cm−1 for C-O-C ether. Scanning electron microscopy (SEM) demonstrated an increase in the average size of the composite up to 428 nm. The energy-dispersive X-ray spectroscopy (EDX) spectrum provided the weight percentages of the C, O, and Ti in the composite were 8.5%, 45.69%, and 45.81%, respectively. The photocatalytic degradation of Direct Red 28 dye under UV irradiation using a composite showed that 86% Direct Red 28 dye was degraded by a 30 mg/L dose of g-C3N4/TiO2/POA in 240 min at pH 2. After four consecutive cycles, the utilized composite showed 79% degradation of Direct Red 28, demonstrating the stability and effectiveness of the g-C3N4/TiO2/POA photocatalyst. The high reusability and efficiency of the g-C3N4/TiO2/POA composite are due to increased light absorption range and reduced e−/h+ recombination rate in the presence of g-C3N4 and POA.

In this study, linear sweep voltammetry (LSV) was implemented for the sensitive detection of 2-nitrophenol (2-NP) in phosphate buffer solution (PBS) at pH 7.00 with lab-made nanocomposite materials for environmental remediation. Initially, a flat glassy carbon electrode (GCE) modified using the inorganic-organic binary Au-NPs@ZnO/CTSN(Chitosan) nanocomposites (NCs) was used as a working electrode (WE). The NCs of Au NPs@ZnO/CTSN were basically prepared by an ultra-sonochemical process and fabricated on a GCE using conducting coating binder such as PEDOT:PSS. Before the electrochemical examination, the Au NPs@ZnO/CTSN NC was fully characterized by Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy-dispersive X-ray Spectroscopy (EDS), Brunauer-Emmett-Teller (BET), X-Ray Diffraction analysis (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), and X-Ray Photoelectron Spectroscopy (XPS) to analyze the functional, morphological, structural, elemental, surface area, crystallinity, and binding energy analyses. A linear concentration range (LDR) of 2-NP from 15⁓150 μM was evaluated by LSV in room conditions. From the slope of the calibration curve, the sensor sensitivity was calculated and found to be 20.9905 μAμM−1cm−2. At signal/noise ratio of 3, the lower limit of detection (LOD) is obtained as 0.45 ± 0.023 μM. Additionally, pH optimization, sensor-probe characterization, stability, and validity are fully analyzed in identical conditions by LSV. Besides this, the assembled 2-NP sensor probe as Au NPs@ZnO/CTSN NCs/PEDOT:PSS/GCE for validity test was performed elaborately and found the reliable and satisfactory results. This is a new approach to the development of electrochemical sensors for environmental chemical analysis using an electrochemical process with gold-nanoparticle decorated ZnO-chitosan for the safety of environmental and healthcare fields on a broad scale.

An electrochemical nitrite sensor probe is introduced herein using a modified flat glassy carbon electrode (GCE) and SrTiO3 material doped with spherical-shaped gold nanoparticles (Au-NPs) and polypyrrole carbon (PPyC) at a pH of 7.0 in a phosphate buffer solution. The nanocomposites (NCs) containing Au-NPs, PPyC, and SrTiO3 were synthesized by ultrasonication, and their properties were thoroughly characterized through structural, elemental, optical, and morphological analyses with various conventional spectroscopic methods, such as field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller method. The peak currents due to nitrite oxidation were characterized in detail and analyzed using conventional cyclic voltammetry (CV) as well as differential pulse voltammetry (DPV) under ambient conditions. The sensor response increased significantly from 0.15 to 1.5 mM of nitrite ions, and the sensor was fabricated by coating a conducting agent (PEDOT:PSS) on the GCE to obtain the Au-NPs/PPyC/SrTiO3 NCs/PEDOT:PSS/GCE probe. The sensor’s sensitivity was determined as 0.5 μA/μM∙cm2 from the ratio of the slope of the linear detection range by considering the active surface area (0.0316 cm2) of the flat GCE. In addition, the limit of detection was determined as 20.00 ± 1.00 µM, which was found to be satisfactory. The sensor’s stability, pH optimization, and reliability were also evaluated in these analyses. Overall, the sensor results were found to be satisfactory. Real environmental samples were then analyzed to evaluate the sensor’s reliability through DPV, and the results showed that the proposed novel electrochemical sensor holds great promise for mitigating water contamination in the real samples with the lab-made Au-NPs/PPyC/SrTiO3 NC. Thus, this study provides valuable insights for improving sensors for broad environmental monitoring applications using the electrochemical approach.

Understanding the eigenvalue distribution of sequence Toeplitz matrices has advanced significantly in recent years. Notable contributors include Bogoya, Grudsky, Böttcher, and Maximenko, who have derived precise asymptotic expansions for these eigenvalues under certain conditions related to the generating function as the matrix size increases. Building on this foundation, the Stefano Serra-Capizzano conjectured that, under certain assumptions about $ \Omega $ and $ \Phi $, a similar expansion may hold for the eigenvalues of a sequence of preconditioned Toeplitz matrices $ T_{n}^{-1}(\Phi) T_n(\Omega) $, given a monotonic ratio $ r = \Omega/\Phi $. In contrast to current eigenvalue solvers, this work presents a novel method for efficiently calculating the eigenvalues of a sequence of large preconditioned banded symmetric Toeplitz matrices (PBST). Our algorithm uses a higher-order spline fitting extrapolation technique to gather spectral data from a smaller sequence of PBST matrices in order to forecast the spectrum of bigger matrices.

This study refines a single-layer Feed-Forward Neural Network (FFNN) for the treatment of textile dye wastewater, concentrating on percentage decolorization (%DEC) and percentage chemical oxygen demand (%COD) reduction. The optimized neural network configuration comprises four input and one output neuron, fine-tuned based on the mean squared error (MSE). The training phase demonstrates a consistent MSE decline, reaching its lowest at epoch 209 for %DEC and epoch 34 for %COD, with corresponding MSEs of $1.799 \times 10^{-5}$ and $ 1.4 \times 10^{-3} $, respectively. The maximum absolute errors for %DEC and %COD were found to be $ 4.0787 $ and $ 2.4486 $, while the mean absolute errors were $ 0.4821 $ and $ 0.7256 $, respectively. In contrast to second-degree polynomial regression, the FFNN model exhibits enhanced predictive accuracy, as indicated by higher $ R^2 $ values of $ 0.99363 $ for %DEC and $ 0.99716 $ for %COD, and reduced error metrics.

Dopamine (DA), a critical biomolecule involved in neurotransmission, is implicated in a variety of neurological disorders. Therefore, accurate detection of DA is crucial for the swift diagnosis of conditions arising from abnormal DA levels. Consequently, we utilized a novel nanocomposite material comprising In2O3-doped ZnO decorated on mesoporous carbon (In2O3·ZnO@MC) as the active nanomaterial for the fabrication of a glassy carbon electrode (GCE). The structural and morphological properties of In2O3·ZnO@MC were comprehensively analyzed utilizing a variety of characterization techniques to confirm its functionality as the sensing nanomaterial. This innovative sensor demonstrates the ability to detect a wide range of DA concentrations, ranging from 0.5 to 2056 μM, in a neutral phosphate buffer solution, exhibiting a high sensitivity of 0.2153 μAμM−1cm−2 and an acceptable detection limit of 0.024 μM. This sensor enables precise DA level measurements in real samples due to its high sensitivity and selectivity. Moreover, it is a dependable and trustworthy sensor for DA measurement due to its outstanding reproducibility, repeatability, and stability.

The primary objective of this research endeavor is to develop a highly sensitive and selective electrochemical sensor for the accurate detection of hydroquinone (HQ), a prevalent environmental contaminant. To achieve this, we employed a novel nanocomposite consisting of Ga2O3-doped ZnO (Ga2O3.ZnO) as the active nanomaterial for fabricating a glassy carbon electrode (GCE). The structure and morphology of the Ga2O3.ZnO nanocomposite were rigorously analyzed using a diverse range of techniques to ensure its suitability as the sensing nanomaterial. This innovative sensor exhibits remarkable capabilities, enabling the detection of HQ across a broad concentration range, spanning from 1 to 11070 µM, in a neutral phosphate buffer solution. It boasts an exceptionally high sensitivity of 1.0229 µA µM−1 cm−2 and an impressive detection limit of 0.063 µM. Thanks to its exceptional sensitivity and specificity, this sensor can precisely quantify HQ levels in real-world samples. Moreover, its outstanding reproducibility, repeatability, and stability establish it as a dependable and resilient choice for HQ determination.

In clinical applications, there is a lack of wound dressings that combine efficient resistance to drug-resistant bacteria with good self-healing properties. In this study, a series of adhesive self-healing conductive antibacterial hydrogel dressings based on oxidized sodium alginate-grafted dopamine/carboxymethyl chitosan/Fe3+ (OSD/CMC/Fe hydrogel)/polydopamine-encapsulated poly(thiophene-3-acetic acid) (OSD/CMC/Fe/PA hydrogel) were prepared for the repair of infected wound. The Schiff base and Fe3+ coordination bonds of the hydrogel structure are dynamic bonds that can be repaired automatically after the hydrogel network is disrupted. Macroscopically, the hydrogel exhibits self-healing properties, allowing the hydrogel dressing to adapt to complex wound surfaces. The OSD/CMC/Fe/PA hydrogel showed good conductivity and photothermal antibacterial properties under near-infrared (NIR) light irradiation. In addition, the hydrogels exhibit tunable rheological properties, suitable mechanical properties, antioxidant properties, tissue adhesion properties and hemostatic properties. Furthermore, all hydrogel dressings improved wound healing in the infected full-thickness defect skin wound repair test in mice. The wound size repaired by OSD/CMC/Fe/PA3 hydrogel + NIR was much smaller (12%) than the control group treated with Tegaderm™ film after 14 days. In conclusion, the hydrogels have high antibacterial efficiency, suitable conductivity, great self-healing properties, good biocompatibility, hemostasis and antioxidant properties, making them promising candidates for wound healing dressings for the treatment of infected skin wounds.

Development and designing of effective visible light photocatalysts to overcome the drastrous situation of water pollution requires material with excellent charge transferring skills. In this regard, an efficient ternary nanocomposite photocatalyst comprised of SnS2 nanostructure linked with polypyrrole-doped carbon black (PPC) and platinum nanoparticles (Pt NPs) was successfully fabricated. Effective ternary photocatalyst was synthesized by hydrothermal technique followed by ultra-sonication and photo-reduction methodologies. The XRD measurements confirmed the hexagonal phase of SnS2, and the proper formation of nanocomposite. TEM examination revealed Pt NPs of 5–15 nm in size, dense cocoon like layered structure of PPC along with irregular pellets of SnS2. Acquired diffuse reflectance data confirmed the visible light band gap of synthesized nanomaterials. The Pt@PPC/SnS2 photocatalyst showed excellent destructive potential under visible light with 92.40 % removal of antibiotic gemifloxacin (GFX) in 30 minutes, almost 347 % more efficient than bare SnS2, and was found to be ultrafast for the removal of methylene blue (MB) with total elimination of dye just in 10 minutes. The photoluminescence and photocurrent transient analysis revealed enhanced light absorption capability and increased photo-induced carrier transfer with effective separation behavior, together with increased effective surface area of the ternary photocatalyst as evidenced by the BET surface area measurement.

Our current research focuses on developing an efficient electrochemical Dopamine sensor for diagnosing neurological disorders related to abnormal Dopamine levels. We utilized a Ga2O3-doped ZnO decorated SWCNT (Ga2O3·ZnO@SWCNT) nanocomposite to modify a glassy carbon electrode. The structure and morphology of the Ga2O3·ZnO@SWCNT nanocomposite was examined utilizing a variety of approaches to ensure of their appropriateness as the sensing nanomaterial. The sensor effectively detects Dopamine within a wide range (1.0–2056 μM) in neutral phosphate buffer solution, exhibiting high sensitivity (0.2536 μAμM−1cm−2) and a practical detection limit (0.052 μM). It accurately quantifies Dopamine in human blood serum and commercial dopamine injection samples, displaying excellent reproducibility, repeatability, and stability. This proposed Dopamine sensor proves to be a reliable tool for Dopamine determination.

In present report, an efficient, reliable ternary photocatalyst based on Bi2O3 nanostructure accompanied by polypyrrole doped carbon black (PPC) and palladium nanoparticles (Pd NPs) was created employing simple ultra-sonication and photo-reduction methodologies for treatment of contaminated water. XRD studies confirmed the tetragonal phase of β-Bi2O3 while elemental composition and nanocomposite development amongst Pd NPs, PPC and Bi2O3 has been confirmed by XPS and FTIR investigations. TEM studies revealed the presence of Pd NPs of 5–15 nm, stacked layers of dense beads of PPC along with irregular ball like particles of Bi2O3 grown in high density in designed ternary photocatalyst. Newly developed Pd@PPC/Bi2O3 photocatalytic framework was found to be highly effective when employed on colorless insecticide imidacloprid (IMD) and methylene blue (MB) dye under visible light. Newly fabricated Pd@PPC/Bi2O3 photocatalyst showed excellent removing skills with 93.60 % elimination of IMD just in 30 min representing 276 % more effectual than pristine Bi2O3. Furthermore, Pd@PPC/Bi2O3 nanostructure was found to be stable and exceptionally active towards MB, with a total dye elimination achieved within 12 min. Enhanced performance of the ternary photocatalyst was attributed to increased surface area, enhanced charge carrier transfer with better separation behavior.

The current chaotic environmental situation especially water pollution prerequisites efficient novel photocatalysts for the proper treatment of these toxic structures through advanced oxidation process. However, the development of active photocatalytic structures requires further committed effort to ensure proper designing and essential band gap. In this report, an attempt has been made to fabricate a rapid and efficient photocatalyst based on SrTiO3 nanostructures, polypyrrole doped carbon black (PPyC) and Au nanoparticles to tackle serious problems of water contamination. Au@PPyC/SrTiO3 ternary photocatalyst was smoothly fabricated by sol gel route followed by ultrasonication and photoreduction technique. X-ray powder diffraction (XRD) studies revealed that SrTiO3 have cubic perovskite structure, while X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) confirmed the formation of ternary framework among Au, PPyC and SrTiO3 nanostructures. Transmission electron microscopy (TEM) revealed that SrTiO3 possessed irregular porous nanoparticles ranging from 10 to 100 nm, whereas the PPyC appeared as well-ordered chain of beads or interconnected branches of nanoparticles. Modification of bare SrTiO3 to Au@PPyC/SrTiO3 significantly increases the surface area to 2.48 times than that of SrTiO3. The photocatalytic performance of the newly developed Au@PPyC/SrTiO3 photocatalyst has been tested on insecticide imidacloprid and on methylene blue (MB) dye. The current Au@PPyC/SrTiO3 photocatalytic framework exhibited ultrafast skills by removing 96.65% of imidacloprid just in 15 min and found to be ∼3.5 times more effective than bare SrTiO3. Besides this Au@PPyC/SrTiO3 photocatalyst was proven to be extremely destructive for resistant MB dye structure.

Inducing roughness to achieve superhydrophobic surfaces through nanoparticlesʹ inclusion is a well-known concept; however, the consistency and secondary pollutants are challenges to be addressed. As a potential solution, we proposed a superhydrophobic nanofibrous membrane through the electrospinning of polyacrylonitrile and hydrophobic polydimethylsiloxane (PAN/H-PDMS) blended solution and post-heat treatment process. During carbonization, a drastic differential shrinkage between PAN and H-PDMS induces a hierarchically nanorough surface of the electrospun nanofiber. Thanks to the synergistic combination of micro-nano scale hierarchical roughness, a significant improvement in superhydrophobicity was observed with the water contact angle (WCA) of 163.48° and sliding angle (SA) of 4.2°. The proposed composite superhydrophobic nanofibrous membrane (CSN-M) exhibited excellent robustness against the tape peel, abrasion, and bending cycles by maintaining WCA higher than 158° and SA less than 6.5°. The outstanding self-healing feature recovered the WCA to 162.25° and lowered the SA to 5.0° after heat treatment at 60 °C. In addition, the CSN-M revealed a tensile modulus of 12.11 Mpa, a hydrostatic pressure of 39.18 cmH2O, and excellent breathability. The developed CSN-M is strong, with high permeability and outstanding mechano-chemical durability, making it a suitable choice for water/oil separation and self-cleaning applications.

Herein, the proposed work reports a simple chemical approach; solution combustion method to synthesize ZnO nanoparticles and Nd-doped ZnO (Nd2O3-ZnO) nanocomposites (0.001 g–5 g) using the combustion technique. The combustion approach is considered one of the environmentally friendly, cost-effective, high yields, and most straightforward procedures for rapidly preparing nanomaterials on a large scale. The prepared nano samples were characterized through standard analytical methods, including scanning electron microscopy (SEM), X-ray Diffraction (XRD), UV–Vis–NIR, and Fourier transform infrared spectroscopy. The XRD results and SEM image showed that the manufactured Nd2O3–ZnO nanostructured samples were crystalline with uniform distribution of Nd dopants on the host ZnO samples, clear with higher Nd concentration ratios. Moreover, as the Nd was raised in the Nd2O3–ZnO nanostructures, the direct energy bandgap values of the Nd: ZnO nanocomposites were detected to decline from 3.35 eV for pure ZnO to reach 3.26 eV, and the indirect bandgap diminished from 3.28 eV to 3.20 eV. All prepared Nd2O3–ZnO samples were applied for photocatalytic degradation of Rhodamine B, Methylene Blue, and both. The photocatalytic efficiency increased with the Nd doping ratio. The best photocatalyst is 0.5 g Nd2O3 doped-ZnO, which degrades Methylene Blue, Rhodamine B, and combination solutions containing both dyes with 100% against ZnO alone with 80% within 60 min under the visible light. Compared to the pure ZnO nanoparticles, the synthesized Nd2O3–ZnO nanostructured samples disclosed improvements in the structural morphology, optical, energy bandgaps, dielectric refraction, and electrical and photocatalytic properties.

The designing of highly specific visible light responsive photocatalysts requires highly dedicative efforts and still a challenging task. The current work focused to design a decidedly novel visible-light derived ternary photocatalyst based on ZnO nanostructures in conjugation with activated carbon (AC) and gold (Au) nanoparticles for environmental remediation task. The AC and AuNPs doped ZnO ternary frameworks were produced by the hydrothermal approach followed by ultra-sonication technique. The XRD data revealed hexagonal wurtzite form of ZnO while the XPS and FTIR investigation confirmed the creation of highly capable framework in conjugation with AC, AuNPs, and ZnO. The TEM images clearly revealed that AuNPs (4–10 nm) were uniformly dispersed onto ZnO nanoparticles (20–80 nm) and the AC possesses sheets like morphology (stacking pattern arrangement). The UV–vis examination demonstrates a lowering of energy band gap upon the incorporation of AC and AuNPs into ZnO matrix. The newly designed novel ternary AC@Au/ZnO photocatalyst was applied for the photocatalytic destruction of gemifloxacin mesylate antibiotic drug under visible light illumination. The impeccable AC@Au/ZnO organization displayed astonishing results with 98.0% destruction of gemifloxacin mesylate drug. The newly fabricated AC@Au/ZnO framework showed the highest degradation efficiency, which was 2.21 times compared to bare ZnO. Additionally, the AC@Au/ZnO ternary framework was found to be highly detrimental during the photodegradation of methylene blue (MB) dye under visible light illumination.

Microstructural, optical, AC dielectric impedance, and conductivity properties of pure PVA and PVA: NaSe SCF samples doped with various NaSe salt fillers were investigated. The XRD study confirmed the semi-crystalline structure of the PolVA:NaSe SCF samples which explicated the semi-crystalline nature of the pure PolVA as a matrix. This is related to a strong intermolecular contact among PolVA chains over intermolecular hydrogen connections. As NaSe salt fillers in the PolVA matrix increased, bandgap energies decreased. The Urbach energy was also changed with the variation of Mo concentration. The AC dielectric properties were enhanced with the introduction of NaSe salt fillers. As the NaSe salt fillers increase, the DC electrical conductivity parameters decrease. The AC impedance parameters infer that the prepared sample is a potential dielectric candidate. The studied material can be used in electronic and optoelectronic applications, especially CUT-OFF laser filters.

The ultimate objective of this research work is to design a sensitive and selective electrochemical sensor for the efficient detection of ascorbic acid (AA), a vital antioxidant found in blood serum that may serve as a biomarker for oxidative stress. To achieve this, we utilized a novel Yb2O3.CuO@rGO nanocomposite (NC) as the active material to modify the glassy carbon working electrode (GCE). The structural properties and morphological characteristics of the Yb2O3.CuO@rGO NC were investigated using various techniques to ensure their suitability for the sensor. The resulting sensor electrode was able to detect a broad range of AA concentrations (0.5–1571 µM) in neutral phosphate buffer solution, with a high sensitivity of 0.4341 µAµM−1cm−2 and a reasonable detection limit of 0.062 µM. The sensor’s great sensitivity and selectivity allowed it to accurately determine the levels of AA in human blood serum and commercial vitamin C tablets. It demonstrated high levels of reproducibility, repeatability, and stability, making it a reliable and robust sensor for the measurement of AA at low overpotential. Overall, the Yb2O3.CuO@rGO/GCE sensor showed great potential in detecting AA from real samples.

Abstract Herein, we demonstrate the effectiveness of surface-enhanced Raman scattering (SERS) to detect trace concentration of potentially harmful imidacloprid pesticide. To achieve this ultimate objective, a rapid and highly effective methodology for the fabrication of active and stable porous silicon (PSi) plated palladium nanoparticles (PdNPs) SERS substrates by an electrochemical anodization and immersion plating routes was applied. The PSi layers were fabricated by the electrochemical anodization of a silicon wafer in ethanoic fluoride solution, followed by uniformly deposition of PdNPs via a simple immersion plating technique. The structural features and morphology of fabricated frameworks of PSi-Pd NPs have been investigated by field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectra. The PSi substrate demonstrates a meso-porous morphology with good distribution, good pore density and average pore sizes around 20 nm. The SERS performance of Si–Pd NPs and PSi–Pd NPs substrates has been examined taking imidacloprid (an insecticide) as a target analyte. The SERS signal of imidacloprid using PSi–Pd NPs substrate exhibited immense enhancement compared to the Si-Pd NPs substrate. The active substrate revealed excellent detectable performance with a concentration as low as 10–9 M imidacloprid and an enhancement factor (EF) of 1.2 × 105. This large EF is fundamentally ascribed to the combined effect of the electromagnetic improvement and charge transfer mechanisms. Additionally, no aging effect was observed for the present substrates kept in air for two weeks. Striking enhancement in Raman spectral signals obtained with the current PSi–Pd NPs substrates can provide a simple and smooth platform towards the sensitive detection of various target analytes.

In this study, gold nanoparticles (AuNPs) decorated polythiophene (Pth) nanocomposite modified glassy carbon electrode (GCE) has been used to fabricate an electrochemical sensor for the sensitive and selective detection of hydrazine. Transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) were used to adequately characterize the nanocomposite. The research findings revealed that AuNPs with cubic phase and diameter range 10–22 nm were monodispersed over the polymeric surface. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) investigation demonstrated that the AuNPs decorated Pth greatly improved the electrocatalytic performance compared with pure Pth modified GCE. This extraordinary electrochemical property is attributed to the synergistic coupling effect between AuNPs and Pth. The mechanistic analysis using CV voltammograms measured in varying scan rates revealed irreversible diffusion-controlled kinetics involving four-electron (4e−) transfer process of hydrazine oxidation. In amperometric (i-t) detection, the proposed sensor showed high sensitivity 0.1817 μAμMcm−2 and a low detection limit 0.77 μM (S/N = 3) over the concentration range 1–963 μM. Moreover, this proposed nanocomposite-based sensor was highly selective toward hydrazine in the presence of common interfering species, especially in high concentrations of sugars (e.g. glucose, sucrose, fructose, and galactose) and exhibited promising analytical results of recovery tests in water samples with acceptable recovery with a relative standard deviation less than 5%.

Herein, a simple hydrothermal rout was developed to produce highly efficient yttrium vanadate (YVO4) nanoparticles photocatalyst for catalytic degradation of methylene blue (MB) dye and phenol as color and colorless organics under UV illumination. The XRD results confirmed a crystalline, single phase of YVO4 with a tetragonal structure at either 12 h (sample Y-12) or 24 h (sample Y-24) hydrothermal treatment. The mesoporous character was evaluated using N2 sorption measurement. The TEM investigation revealed self-assembled

ZnO-doped Polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) polymeric films were prepared in this study through an easy and inexpensive solution-casting method. The scope of the study was based on the structural, dielectric, and optical parameters, as well as on the optical limiting effects of the ZnO-doped polymer blend (PB) as nanocomposite films. The X-ray diffraction (XRD) analysis indicated that the synthesized nanocomposites were semicrystalline. The calculated crystalline size of the polymeric semicrystalline peak decreased as ZnO increased or enhanced the blend polymer. Fourier’s transformer infrared (FT-IR) study confirmed a substantial dispersion of ZnO nanoparticles in a polymeric PVA/PVP matrix. The optical absorption properties suggested focusing on the surface plasmonic peak (SPR). The refractive index values ranged from 1.718 for the pure PB ZnO0 sample in the Hossam, Ibrahim, and Heba model to 3.036 for the PB ZnO5 film from the Anani model. Nonlinear optical parameters (χ((3)), and n(2)) were calculated and analyzed for the PB ZnO nanocomposite films under investigation. The maximum value for χ((1)) was 0.550, while for χ((3)), its susceptibility value was 155.85 × 10−13 esu, and for the nonlinear refractive index (n((2)), it was 20.87 × 10−11 esu. A gradual decrease was revealed in the optical limiting sources, as a high content of ZnO was induced in the blend PVA/PVP polymer. Due to their unique properties, these materials can be used in electronic and optoelectronic devices.

Nanoscale surface roughness has conventionally been induced by using complicated approaches; however, the homogeneity of superhydrophobic surface and hazardous pollutants continue to have existing challenges that require a solution. As a prospective solution, a novel bubbled-structured silica nanoparticle (SiO2) decorated electrospun polyurethane (PU) nanofibrous membrane (SiO2@PU-NFs) was prepared through a synchronized electrospinning and electrospraying process. The SiO2@PU-NFs nanofibrous membrane exhibited a nanoscale hierarchical surface roughness, attributed to excellent superhydrophobicity. The SiO2@PU-NFs membrane had an optimized fiber diameter of 394 ± 105 nm and was fabricated with a 25 kV applied voltage, 18% PU concentration, 20 cm spinning distance, and 6% SiO2 nanoparticles. The resulting membrane exhibited a water contact angle of 155.23°. Moreover, the developed membrane attributed excellent mechanical properties (14.22 MPa tensile modulus, 134.5% elongation, and 57.12 kPa hydrostatic pressure). The composite nanofibrous membrane also offered good breathability characteristics (with an air permeability of 70.63 mm/s and a water vapor permeability of 4167 g/m2/day). In addition, the proposed composite nanofibrous membrane showed a significant water/oil separation efficiency of 99.98, 99.97, and 99.98% against the water/xylene, water/n-hexane, and water/toluene mixers. When exposed to severe mechanical stresses and chemicals, the composite nanofibrous membrane sustained its superhydrophobic quality (WCA greater than 155.23°) up to 50 abrasion, bending, and stretching cycles. Consequently, this composite structure could be a good alternative for various functional applications.

The new proton-conducting composite electrolyte films (PCCEFs) consisting of polyvinyl alcohol (PVA) with varying ammonium fluoride salt concentrations were created using an expanded liquid casting process. The X-ray diffraction (XRD) study confirms the composite electrolyte films (CEFs) formation. The improvement in AMF02 salt doping compared to the PVA matrix film approach resulted in decreased variation in the crystalline size values, thus explaining how [NH4+] and polymer PVA matrix films interact. The band gaps decrease when the AMF02 salt filler concentration increases due to increased crystallite size. The suggested composites evaluated successful CUT-OFF laser filters and attenuation, as well as limiting laser power systems. For the 11.11 wt% AMF02 doping salt, the highest DC conductivity was 73.205 × 10−9 (siemens/m) at ambient temperature. Our dielectric results demonstrate that the CEFs are usually suitable for optoelectronic systems. There is a huge need to develop low dielectric permittivity composite electrolyte films (CEFs) for microelectronic devices and the high-frequency region.

Successful integration of perovskite cell with silicon cell to form a tandem solar device has shown tremendous potential for outperforming the state-of-the-art single junction silicon devices. This tandem approach has enabled high efficiencies up to 29% within a short period of time and one can find sufficient work and various strategies being applied to enhance the efficiency in these devices. At this point in time, a compilation of all these studies, with a critical review and perspectives is extremely relevant and essential. With this motivation the present review has been brought out, with all achievements attained so far by optimizing various components namely the electron/hole transport layer and absorber layer, functional layers in bottom cell, transparent contacts, deposition techniques and the innovative light management tactics used. The review also outlines the solutions proposed by various researchers to overcome the challenges that restrict the efficiency of tandem strategy in three distinct configurations, namely, monolithic (2T), four terminal (4T) and three terminal (3T) configurations. Finally, the perspectives provide real insights into choosing suitable materials, techniques and methods and achieve efficiencies near and beyond Shockley Queisser limit, thus spiking high hopes that this device would be the dominant energy conversion device in future.

Nanofiber-based facial masks have attracted the attention of modern cosmetic applications due to their controlled drug release, biocompatibility, and better efficiency. In this work, Azadirachta indica extract (AI) incorporated electrospun polyvinyl alcohol (PVA) nanofiber membrane was prepared to obtain a sustainable and hydrophilic facial mask. The electrospun AI incorporated PVA nanofiber membranes were characterized by scanning electron microscope, Ultraviolet-visible spectroscopy (UV-Vis) drug release, water absorption analysis, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging, and antibacterial activity (qualitative and quantitative) at different PVA and AI concentrations. The optimized nanofiber of 376 ± 75 nm diameter was obtained at 8 wt/wt% PVA concentration and 100% AI extract. The AI nanoparticles of size range 50~250 nm in the extract were examined through a zeta sizer. The water absorption rate of ~660% and 17.24° water contact angle shows good hydrophilic nature and water absorbency of the nanofiber membrane. The UV-Vis also analyzed fast drug release of >70% in 5 min. The prepared membrane also exhibits 99.9% antibacterial activity against Staphylococcus aureus and has 79% antioxidant activity. Moreover, the membrane also had good mechanical properties (tensile strength 1.67 N, elongation 48%) and breathability (air permeability 15.24 mm/s). AI-incorporated nanofiber membrane can effectively be used for facial mask application.

Exposure to hydroquinone (HQ) can cause various health hazards and negative impacts on the environment. Therefore, we developed an efficient electrochemical sensor to detect and quantify HQ based on palladium nanoparticles deposited in a porous silicon-polypyrrole-carbon black nanocomposite (Pd@PSi−PPy−C)-fabricated glassy carbon electrode. The structural and morphological characteristics of the newly fabricated Pd@PSi−PPy−C nanocomposite were investigated utilizing FESEM, TEM, EDS, XPS, XRD, and FTIR spectroscopy. The exceptionally higher sensitivity of 3.0156 μAμM−1 cm−2 and a low limit of detection (LOD) of 0.074 μM were achieved for this innovative electrochemical HQ sensor. Applying this novel modified electrode, we could detect wide-ranging HQ (1–450 μM) in neutral pH media. This newly fabricated HQ sensor showed satisfactory outcomes during the real sample investigations. During the analytical investigation, the Pd@PSi−PPy−C/GCE sensor demonstrated excellent reproducibility, repeatability, and stability. Hence, this work can be an effective method in developing a sensitive electrochemical sensor to detect harmful phenol derivatives for the green environment.

Sweat is a natural body excretion produced by skin glands, and the body cools itself by releasing salty sweat. Wetness in the underarms and feet for long durations causes itchiness and an unpleasant smell. Skin-friendly reusable sweat pads could be used to absorb sweat. Transportation of moisture and functionality is the current challenge that many researchers are working on. This study aims to develop a functional and breathable sweat pad with antimicrobial and quick drying performance. Three layered functional sweat pads (FSP) are prepared in which the inner layer is made of an optimized needle-punched coolmax/polypropylene nonwoven blend. This layer is then dipped in antimicrobial ZnO solution (2, 4, and 6 wt.%), and super absorbent polymer (SAP) is embedded, and this is called a functional nonwoven (FNW1) sheet. Electrospun nanofiber-based nanomembranes of polyamide-6 are optimized for bead-free fibers. They are used as a middle layer to enhance the pad’s functionality, and the third layer is again made of needle-punched optimized coolmax/polypropylene nonwoven sheets. A simple nonwoven-based sweat pad (SSP) is also prepared for comparison purposes. Nonwoven sheets are optimized based on better comfort properties, including air/water vapor permeability and moisture management (MMT). Nonwoven webs having a higher proportion of coolmax show better air permeability and moisture transfer from the inner to the outer layer. Antimicrobial activity of the functional nonwoven layer showed 8 mm of bacterial growth, but SSP and FSP showed only 6 mm of growth against Staphylococcus aureus. FSP showed superior comfort and antibacterial properties. This study could be a footstone toward highly functional sweat pads with remarkable comfort properties.

Synthetic antibiotics have captured the market in recent years, but the side effects of these products are life-threatening. In recent times, researchers have focused their research on natural-based products such as natural herbal oils, which are eco-friendly, biocompatible, biodegradable, and antibacterial. In this study, polyethylene oxide (PEO) and aqueous ginger extract (GE) were electrospun to produce novel antibacterial nanomembrane sheets as a function of PEO and GE concentrations. A GE average particle size of 91.16 nm was achieved with an extensive filtration process, inferring their incorporation in the PEO nanofibres. The presence of the GE was confirmed by Fourier transform infrared spectroscopy (FTIR) through peaks of phenol and aromatic groups. The viscoelastic properties of PEO/GE solutions were analysed in terms of PEO and GE concentrations. Increasing PEO and GE concentrations increased the solution’s viscosity. The dynamic viscosity of 3% was not changed with increasing shear rate, indicating Newtonian fluid behaviour. The dynamic viscosity of 4 and 5 wt% PEO/GE solutions containing 10% GE increased exponentially compared to 3 wt%. In addition, the shear thinning behaviour was observed over a frequency range of 0.05 to 100 rad/s. Scanning Electron Microscopy (SEM) analysis also specified an increase in the nanofibre’s diameter with increasing PEO concentration, while SEM images displayed smooth morphology with beadless nanofibres at different PEO/GE concentrations. In addition, PEO/GE nanomembranes inhibited the growth of Staphylococcus aureus, as presented by qualitative antibacterial results. The extent of PEO/GE nanomembrane’s antibacterial activity was further investigated by the agar dilution method, which inhibited the 98.79% Staphylococcus aureus population at 30% GE concentration.

Textile-supported nanocomposite as a scaffold has been extensively used in the medical field, mainly to give support to weak or harmed tissues. However, there are some challenges in fabricating the nanofiber/textile composite, i.e., suitable porous structure with defined pore size, less skin contact area, biocompatibility, and availability of degradable materials. Herein, polyamide-6 (PA) nanofibers were synthesized using needleless electrospinning with the toothed wheel as a spinneret. The electrospinning process was optimized using different process and solution parameters. In the next phase, optimized PA nanofiber membranes of optimum fiber diameter with uniform distribution and thickness were used in making nanofiber membrane–textile composite. Different textile fabrics (woven, non-woven, knitted) were developed. The optimized nanofiber membranes were combined with non-woven, woven, and knitted fabrics to make fabric-supported nanocomposite. The nanofiber/fabric composites were compared with available market woven and knitted meshes for mechanical properties, morphology, structure, and chemical interaction analysis. It was found that the tear strength of the nanofiber/woven composite was three times higher than market woven mesh, and the nanofiber/knitted composite was 2.5 times higher than market knitted mesh. The developed composite structures with woven and knitted fabric exhibited improved bursting strength (613.1 and 751.1 Kpa), tensile strength (195.76 and 227.85 N), and puncture resistance (68.76 and 57.47 N), respectively, than market available meshes. All these properties showed that PA nanofibers/textile structures could be utilized as a composite with multifunctional properties.

Herein, an ultra-sonication technique followed by a photoreduction technique was implemented to prepare silver nanoparticle-decorated Chitosan/SrSnO3 nanocomposites (Ag-decorated Chitosan/SrSnO3 NCs), and they were successively used as electron-sensing substrates coated on a glassy carbon electrode (GCE) for the development of a 2,6-dinitrophenol (2,6-DNP) efficient electrochemical sensor. The synthesized NCs were characterized in terms of morphology, surface composition, and optical properties using FESEM, TEM, HRTEM, BET, XRD, XPS, FTIR, and UV-vis analysis. Ag-decorated Chitosan/SrSnO3 NC/GCE fabricated with the conducting binder (PEDOT:PSS) was found to analyze 2,6-DNP in a wide detection range (LDR) of 1.5~13.5 µM by applying the differential pulse voltammetry (DPV) approach. The 2,6-DNP sensor parameters, such as sensitivity (54.032 µA µM−1 cm−2), limit of detection (LOD; 0.18 ± 0.01 µM), limit of quantification (LOQ; 0.545 µM) reproducibility, and response time, were found excellent and good results. Additionally, various environmental samples were analyzed and obtained reliable analytical results. Thus, it is the simplest way to develop a sensor probe with newly developed nanocomposite materials for analyzing the carcinogenic contaminants from the environmental effluents by electrochemical approach for the safety of environmental and healthcare fields in a broad scale.

In this study, a selective 4-nitrophenol (4-NP) sensor was developed onto a glassy carbon electrode (GCE) as an electron-sensing substrate, which decorated with sol–gel, prepared Pt nanoparticles- (NPs) embedded polypyrole-carbon black (PPy-CB)/ZnO nanocomposites (NCs) using differential pulse voltammetry. Characterizations of the NCs were performed using Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS), Ultraviolet–visible Spectroscopy (UV–vis), Fourier Transform Infrared Spectroscopy (FTIR), High Resolution Transmission Electron Microscopy (HRTEM), and X-ray Diffraction Analysis (XRD). The GCE modified by conducting coating binders [poly(3,4-ethylenedioxythiophene) polystyrene sulfonate; PEDOT:PSS] based on Pt NPs/PPy-CB/ZnO NCs functioned as the working electrode and showed selectivity toward 4-NP in a phosphate buffer medium at pH 7.0. Our analysis of 4-NP showed the linearity from 1.5 to 40.5 µM, which was identified as the linear detection range (LDR). A current versus concentration plot was formed and showed a regression co-efficient R2 of 0.9917, which can be expressed by ip(µA) = 0.2493C(µM) + 15.694. The 4-NP sensor sensitivity was calculated using the slope of the LDR, considering the surface area of the GCE (0.0316 cm2). The sensitivity was calculated as 7.8892 µA µM−1 cm−2. The LOD (limit of detection) of the 4-NP was calculated as 1.25 ± 0.06 µM, which was calculated from 3xSD/σ (SD: Standard deviation of blank response; σ: Slope of the calibration curve). Limit of quantification (LOQ) is also calculated as 3.79 µM from LOQ = 10xLOD/3.3. Sensor parameters such as reproducibility, response time, and analyzing stability were outstanding. Therefore, this novel approach can be broadly used to safely fabricate selective 4-NP sensors based on nanoparticle-decorated nanocomposite materials in environmental measurement.

Chemical sensors fabricated from porous silicon (PSi) for liquid organic analytes (ethanol, acetonitrile, methanol and acetone) are demonstrated, with an emphasis on the impact of the Ag electrical contact placement on sensor performance. Sensors with front side contact display larger shift in capacitance response (2–3 times more sensitive) compared to the backside sensor design as the solvents immediately interact with the pore openings before infiltration. Much slower response time (7–30 min range) for front side vs. (50–200 s scale range) for backside configuration is observed. Both sensor designs exhibit excellent solvent infiltration-evaporation reversible response, indicating no chemical reaction or surface modification occurred. The response time was in the order of ethanol > acetonitrile > methanol > acetone, which correlates well with the solvent vapor pressure. The capacitance shift in both sensor devices is likely related to the interface interaction, revealing a closer correlation with the dipole moments of solvents. This is supported by the photoluminescence quenching upon exposure to organic solvents, with a relative intensity decrease tracks with the dipole moment. The sensitivity remains sufficiently high during the repeated use, with excellent storage stability for backside contact. This comparative study suggests the viability of the current sensor structure and design particularly with backside contact for sensing of various chemical analytes with notably sensitivity and extremely rapid response. Keywords: Meso-porous silicon, Electrical sensor, Capacitance, Photoluminescence, Organic solvents

Copper-silver and cobalt-silver alloy nanoparticles deposited on reduced graphene oxide (CuAg/rGO and CoAg/rGO) were synthesized and examined as electrocatalysts for oxygen reduction reaction (ORR) and hydrogen peroxide reduction reaction (HPRR) in alkaline media. Characterization of the prepared samples was done by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction analysis (XRD), and scanning electron microscopy with integrated energy-dispersive X-ray spectroscopy (SEM-EDS). CuAg/rGO and CoAg/rGO nanoparticles diameter ranged from 0.4 to 9.2 nm. The Ag loading was ca. 40 wt.% for both electrocatalysts, with that for Cu and Co being 35 and 17 wt.%, respectively. CoAg/rGO electrocatalyst showed a Tafel slope of 109 mV dec−1, significantly lower than that for CuAg/rGO (184 mV dec−1), suggesting faster ORR kinetics. Additionally, a higher diffusion current density was obtained for CoAg/rGO (−2.63 mA cm−2) than for CuAg/rGO (−1.74 mA cm−2). The average value of the number of electrons transferred during ORR was 2.8 for CuAg/rGO and 3.3 for CoAg/rGO electrocatalyst, further confirming the higher ORR activity of the latter. On the other hand, CuAg/rGO showed higher peak current densities (−3.96 mA cm−2) for HPRR compared to those recorded for CoAg/rGO electrocatalyst (−1.96 mA cm−2).

Platinum–dysprosium (Pt–Dy) alloys prepared by the arc melting technique are assessed as potential electrodes for the oxygen reduction reaction (ORR) using voltammetry and chronoamperometry in alkaline media. A relatively small change (10 at.%) in the alloy composition brought a notable difference in the alloys’ performance for the ORR. Pt40Dy60 electrode, i.e., the electrode with a lower amount of Pt, was identified to have a higher activity towards ORR as evidenced by lower overpotential and higher current densities under identical experimental conditions. Furthermore, DFT calculations point out the unique single-atom-like coordination and electronic structure of Pt atoms in the Pt40Dy60 surface as responsible for enhanced ORR activity compared to the alloy with a higher Pt content. Additionally, Pt–Dy alloys showed activity in the oxygen evolution reaction (OER), with the OER current density lower than that of pure Pt.

Cyber-threats are becoming a big concern due to the potential severe consequences of such threats is false data injection (FDI) attacks where the measures data is manipulated such that the detection is unfeasible using traditional approaches. This work focuses on detecting FDIs for phasor measurement units where compromising one unit is sufficient for launching such attacks. In the proposed approach, moving averages and correlation are used along with machine learning algorithms to detect such attacks. The proposed approach is tested and validated using the IEEE 14-bus and the IEEE 30-bus test systems. The proposed performance was sufficient for detecting the location and attack instances under different scenarios and circumstances.

For specialized applications, it is incumbent to develop new materials that enable manufacturers to develop new processes and designs. For better fuel economy, structural integrity, and lightweight applications, the development of bimetallic steel/aluminum (Al) alloys having a strong interfacial bond is required. Therefore, a mild steel/Al-bearing alloy bimetallic composite was investigated in this study. Firstly, a tin (Sn) interlayer was developed between the steel substrate and the Al-bearing alloy by the tinning process. For further improvement in the interfacial integrity, alumina (Al2O3) nanoparticles were added to the Sn powder during the tinning process. Four different wt.% of Al2O3 nanoparticles of 0.25, 0.5, 1, and 1.5 were added and mixed thoroughly with Sn powder before mixing them with flux prior to the tinning process. Finally, molten Al-bearing alloy (Al–Sn-Si–Cu) was poured over the Al2O3 nanoparticles reinforced tinned steel substrate. A cross-section of the steel/Al-bearing alloy bimetallic composite was prepared for optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and shear testing. The cross-section microstructure of the steel/Al-bearing alloy bimetallic composite revealed irregular and discontinuous interfacial layers in the case of the low-temperature (170 °C) tinning process. However, a uniform, continuous interfacial layer was fabricated during the tinning process when additional preheat to the steel substrate and tinning process was adopted. It can be reported that low Al2O3 nanoparticles loading (0.25%) and steel substrate preheating were recommended for the better interfacial layer in the steel/Al-bearing alloy bimetallic composite.

Abstract Mesoporous α–Fe2O3 has been synthesized via a simple sol-gel procedure in the presence of Pluronic (F-127) triblock copolymer as structure directing agent. Silver (Ag) nanoparticles were deposited onto α–Fe2O3 matrix by the photochemical reduction approach. Morphological analysis revealed the formation of Ag nanoparticles with small sizes

The power industry is in the process of grid modernization with the introduction of phasor measurement units (PMUs), advanced metering infrastructure (AMI), and other technologies. Although these technologies enable more reliable and efficient operation, the risk of cyber threats has increased, as evidenced by the recent blackouts in Ukraine and New York. One of these threats is false data injection attacks (FDIAs). Most of the FDIA literature focuses on the vulnerability of DC estimators and AC estimators to such attacks. This paper investigates FDIAs for PMU-based state estimation, where the PMUs are comparable. Several states can be manipulated by compromising one PMU through the channels of that PMU. A Phase Locking Value (PLV) technique was developed to detect FDIAs. The proposed approach is tested on the IEEE 14-bus and the IEEE 30-bus test systems under different scenarios using a Monte Carlo simulation where the PLV demonstrated an efficient performance.