Chemical synthesis and super capacitance performance of novel CuO@Cu4O3/rGO/PANI nanocomposite electrode.

Copper oxide-based nanocomposites are promising electrode materials for high-performance supercapacitors due to their unique properties that aid electrolyte access and ion diffusion to the electrode surface. Herein, a facile and low-cost synthesis in situ strategy based on co-precipitation and incorporation processes of reduced graphene oxide (rGO), followed by in situ oxidative polymerization of aniline monomer has been reported. CuO@Cu4O3/rGO/PANI nanocomposite revealed the good distribution of CuO@Cu4O3 and rGO within the polymer matrix which allows improved electron transport and ion diffusion process. Galvanostatic charge-discharge (GCD) results displayed a higher specific capacitance value of 508 F g-1 for CuO@Cu4O3/rGO/PANI at 1.0 A g-1 in comparison to the pure CuO@Cu4O3 278 F g-1. CuO@Cu4O3/rGO/PANI displays an energy density of 23.95 W h kg-1 and power density of 374 W kg-1 at the current density of 1 A g-1 which is 1.8 times higher than that of CuO@Cu4O3 (13.125 W h kg-1) at the same current density. The retention of the electrode was 93% of its initial capacitance up to 5000 cycles at a scan rate of 100 mV s-1. The higher capacitance of the CuO@Cu4O3/rGO/PANI electrode was credited to the formation of a fibrous network structure and rapid ion diffusion paths through the nanocomposite matrix that resulted in enhanced surface-dependent electrochemical properties.

Synergetic and advanced isotherm investigation for the enhancement influence of zeolitization and ß-cyclodextrin hybridization on the retention efficiency of U(vi) ions by diatomite.

In synergetic investigations, the adsorption effectiveness of diatomite-based zeolitic structure (ZD) as well as its ß-cyclodextrin (CD) hybrids (CD/ZD) towards uranium ions (U(vi)) was evaluated to examine the influence of the transformation procedures. The retention behaviors and mechanistic processes have been demonstrated through analyzing the steric and energetic factors employing the modern equilibrium approach (a monolayer model with a single energy level). After the saturation phase, the uptake characteristics of U(vi) were dramatically improved to 297.5 mg g-1 after the CD blending procedure versus ZD (262.3 mg g-1) or 127.8 mg g-1. The steric analysis indicated a notable increase in binding site levels after the zeolitization steps (Nm = 85.7 mg g-1) as well as CD implementation (Nm = 91.2 mg g-1). This finding clarifies the reported improvement in the ability of CD/ZD to effectively retain the U(vi) ions. Furthermore, every single active site of the CD/ZD material has the capacity to adsorb around four ions, which are aligned according to a vertical pattern. The energetic aspects, specifically Gaussian energy (<8 kJ mol-1) along with retention energy (<40 kJ mol-1), validate the regulated influences of the physical mechanistic processes. The physical adsorption of U(vi) seems to depend on various intermolecular forces, such as van der Waals forces, in conjunction with zeolitic ion exchanging pathways (0.6-25 kJ mol-1). The thermodynamic assets have been evaluated to confirm the exothermic together with spontaneous adsorption U(vi) by ZD and its blend with CD (CD/ZD).

Steric and energetic studies on the influence of cellulose on the adsorption effectiveness of Mg trapped hydroxyapatite for enhanced remediation of chlorpyrifos and omethoate pesticides.

Magnesium-trapped hydroxyapatite (Mg.HP) was hybridized with cellulose fiber to produce a bio-composite (CLF/HP) with enhanced adsorption affinities for two types of toxic pesticides (chlorpyrifos (CF) and omethoate (OM)). The enhancement influence of the hybridized cellulose on the adsorption performances of Mg.HP was illustrated based on the determined steric and energetic factors. The computed CF and OM adsorption performances of CLF/HP during the saturation phases are 279.8 mg/g and 317.9 mg/g, respectively, which are significantly higher than the determined values using Mg/HP (143.4 mg/g (CF) and 145.3 mg/g (OM)). The steric analysis demonstrates a strong impact of the hybridization process on the reactivity of the surface of the composite. While CLF/HP reflects effective uptake site densities (Nm) of 93.3 mg/g (CF) and 135.3 mg/g (OM), the estimated values for Mg.HP are 51.2 mg/g (CF) and 46.11 mg/g (OM), which explain the reported enhancement in the adsorption performances of the composite. The capacity of each uptake site to be occupied with more than one molecule (n (CF) = 3-3.74 and n (OM) = 2.35-3.54) suggests multimolecular uptake. The energetic factors suggested physical mechanistic processes of spontaneous and exothermic behaviors either during the uptake of CF or OM.

High-performance biosensors based on angular plasmonic of a multilayer design: new materials for enhancing sensitivity of one-dimensional designs.

In this study, a theoretical examination is conducted to investigate the biosensing capabilities of different surface plasmon resonance (SPR) based hybrid multilayer structures, which are composed of two-dimensional (2D) materials. The transfer matrix formulation is implemented to calibrate the results of this study. A He-Ne laser of wavelength = 632.8 nm is used to simulate the results. Many permutations and combinations of layers of silver (Ag), aluminum oxynitride (AlON), and 2D materials were utilized to obtain the optimized structure. Ten dielectrics and twelve 2D materials were tested for a highly sensitive multilayer hybrid sensing design, which is composed of the prism (Ohara S-FPL53)/Ag/AlON/WS2/AlON/sensing medium. The optimized biosensing design is capable of sensing and detecting analytes whose refractive variation is limited between 1.33 and 1.34. The maximum sensitivity, which is achieved by using the proposed design is 488.2° per RIU. Additionally, the quality factor, figure of merit, detection limit, and qualification limit values of the optimized design were also calculated to obtain a true picture of the sensing capabilities. The designing approach based on the multilayer hybrid SPR biosensors has the potential to develop various plasmonic biosensors that are related to food, chemical, and biomedical engineering fields.

Effective retention of cesium ions from aqueous environment using morphologically modified kaolinite nanostructures: experimental and theoretical studies.

Kaolinite can undergo a controlled morphological modification process into exfoliated nanosilicate sheets (EXK) and silicate nanotubes (KNTs). The modified structures were assessed as potential effective adsorbents for the retention of Cs+ ions. The impact of the modification process on the retention properties was assessed based on conventional and advanced equilibrium studies, considering the related steric and energetic functions. The synthetic KNTs exhibit a retention capacity of 249.7 mg g-1 as compared to EXK (199.8 mg g-1), which is significantly higher than raw kaolinite (73.8 mg g-1). The kinetic modeling demonstrates the high effectiveness of the pseudo-first-order kinetic model (R2 > 0.9) to illustrate the sequestration reactions of Cs+ ions by K, EXK, and KNTs. The enhancement effect of the modification processes can be illustrated based on the statistical investigations. The presence of active and vacant receptors enhanced greatly from 19.4 mg g-1 for KA to 40.8 mg g-1 for EXK and 46.9 mg g-1 for KNTs at 298 K. This validates the significant impact of the modification procedures on the specific surface area, reaction interface, and reacting chemical groups' exposure. This also appeared in the enhancement of the reactivity of their surfaces to be able to uptake 10 Cs+ ions by KNTs and 5 ions by EXK as compared to 4 ions by kaolinite. The thermodynamic and energetic parameters (Gaussian energy < 8.6 kJ mol-1; uptake energy < 40 kJ mol-1) show that the physical processes are dominant, which have spontaneous and exothermic properties. The synthetic EXK and KNT structures validate the high elimination performance of the retention of Cs+ either in the existence of additional anions or cations.

Sensing of heavy metal Pb2+ ions in water utilizing the photonic structure of highly controlled hexagonal TiON/TiO2 nanotubes.

The detection of heavy metals in water, especially Pb2+ ions, is important due to their severe hazardous effects. To address this issue, a highly controlled hexagonal TiON/TiO2 heterostructure has been synthesized in this study. The fabrication process involved the utilization of atomic layer deposition and direct current sputtering techniques to deposit TiO2 and TiON layers onto a porous Al2O3 membrane used as a template. The resulting heterostructure exhibits a well-ordered hollow tube structure with a diameter of 345 nm and a length of 1.2 µm. The electrochemical sensing of Pb2+ ions in water is carried out using a cyclic voltammetry technique under both light and dark conditions. The concentration range for the Pb2+ ions ranges from 10-5 to 10-1 M. The sensitivity values obtained for the sensor are 1.0 × 10-6 in dark conditions and 1.0 × 10-4 in light conditions. The remarkable enhancement in sensitivity under light illumination can be attributed to the increased activity and electron transfer facilitated by the presence of light. The sensor demonstrates excellent reproducibility, highlighting its reliability and consistency. These findings suggest that the proposed sensor holds great promise for the detection of Pb2+ ions in water, thereby facilitating environmental monitoring, water quality assessment, and safety regulation across various industries. Furthermore, the eco-friendly and straightforward preparation techniques employed in its fabrication provide a significant advantage for practical and scalable implementation.

Lp Quasi-norm Minimization: Algorithm and Applications.

Sparsity finds applications in diverse areas such as statistics, machine learning, and signal processing. Computations over sparse structures are less complex compared to their dense counterparts and need less storage. This paper proposes a heuristic method for retrieving sparse approximate solutions of optimization problems via minimizing the ℓp quasi-norm, where 0

SILAR-Deposited CuO Nanostructured Films Doped with Zinc and Sodium for Improved CO2 Gas Detection.

Gas sensing is of significant importance in a wide range of disciplines, including industrial safety and environmental monitoring. In this work, a low-cost SILAR (Successive Ionic Layer Adsorption and Reaction) technique was employed to fabricate pure CuO, Zn-doped CuO, and Na-doped CuO nanotextured films to efficiently detect CO2 gas. The structures, morphologies, chemical composition, and optical properties of all films are characterized using different tools. All films exhibit a crystalline monoclinic phase (tenorite) structure. The average crystallite size of pure CuO was 83.5 nm, whereas the values for CuO/Zn and CuO/Na were 73.15 nm and 63.08 nm, respectively. Subsequently, the gas-sensing capabilities of these films were evaluated for the detection of CO2 in terms of sensor response, selectivity, recovery time, response time, and limits of detection and quantification. The CuO/Na film offered the most pronounced sensitivity towards CO2 gas, as evidenced by a sensor response of 12.8% at room temperature and a low limit of detection (LoD) of 2.36 SCCM. The response of this sensor increased to 64.5% as the operating temperature increased to 150 °C. This study thus revealed a brand-new CuO/Na nanostructured film as a highly effective and economically viable sensor for the detection of CO2.

Enhanced Sensitivity of Binary/Ternary Locally Resonant Porous Phononic Crystal Sensors for Sulfuric Acid Detection: A New Class of Fluidic-Based Biosensors.

This research presented a comprehensive study of a one-dimensional (1D) porous silicon phononic crystal design as a novel fluidic sensor. The proposed sensor is designed to detect sulfuric acid (H2SO4) within a narrow concentration range of 0-15%. Sulfuric acid is a mineral acid extensively utilized in various physical, chemical, and industrial applications. Undoubtedly, its concentration, particularly at lower levels, plays a pivotal role in these applications. Hence, there is an urgent demand for a highly accurate and sensitive tool to monitor even the slightest changes in its concentration, which is crucial for researchers. Herein, we presented a novel study on the optimization of the phononic crystal (PnC) sensor. The optimization process involves a comparative strategy between binary and ternary PnCs, utilizing a multilayer stack comprising 1D porous silicon (PSi) layers. Additionally, a second comparison is conducted between conventional Bragg and local resonant PnCs to demonstrate the design with the highest sensitivity. Moreover, we determine the optimum values for the materials' thickness and number of periods. The results revealed that the ternary local resonant PnC design with the configuration of {silicone rubber/[PSi1/PSi2/PSi3]N/silicone rubber} is the optimal sensor design. The sensor provided a super sensitivity of 2.30 × 107 Hz for a concentration change of just 2%. This exceptional sensitivity is attributed to the presence of local resonant modes within the band gap of PnCs. The temperature effects on the local resonant modes and sensor performance have also been considered. Furthermore, additional sensor performance parameters such as quality factor, figure of merit, detection limit, and damping rate have been calculated to demonstrate the effectiveness of the proposed liquid sensor. The transfer matrix method was utilized to compute the transmission spectra of the PnC, and Hashin's expression was employed to manipulate the porous silicon media filled with sulfuric acid at various concentrations. Lastly, the proposed sensor can serve as an efficient tool for detecting acidic rain, contaminating freshwater, and assessing food and liquid quality, as well as monitoring other pharmaceutical products.

A theoretical approach for a new design of an ultrasensitive angular plasmonic chemical sensor using black phosphorus and aluminum oxide architecture.

In this study, the biosensing capabilities of conventional and hybrid multilayer structures were theoretically examined based on surface plasmon resonance (SPR). The transfer matrix method is adopted to obtain the reflectance spectra of the hybrid multilayer structure in the visible region. In this regard, the considered SPR sensor is configured as, [prism (CaF2)/Al2O3/Ag/Al2O3/2D material/Al2O3/Sensing medium]. Interestingly, many optimization steps were conducted to obtain the highest sensitivity of the new SPR biosensor from the hybrid structure. Firstly, the thickness of an Al2O3 layer with a 2D material (Blue P/WS2) is optimized to obtain an upgraded sensitivity of 360° RIU-1. Secondly, the method to find the most appropriate 2D material for the proposed design is investigated to obtain an ultra-high sensitivity. Meanwhile, the inclusion of black phosphorus (BP) increases the sensor's sensitivity to 466° RIU-1. Thus, black phosphorus (BP) was obtained as the most suitable 2D material for the proposed design. In this regard, the proposed hybrid SPR biosensing design may pave the way for further opportunities for the development of various SPR sensors to be utilized in chemical and biomedical engineering fields.

Photonic crystal nanostructure as a photodetector for NaCl solution monitoring: theoretical approach.

In this research, we have a theoretical simple and highly sensitive sodium chloride (NaCl) sensor based on the excitation of Tamm plasmon resonance through a one-dimensional photonic crystal structure. The configuration of the proposed design was, [prism/gold (Au)/water cavity/silicon (Si)/calcium fluoride (CaF2)10/glass substrate]. The estimations are mainly investigated based on both the optical properties of the constituent materials and the transfer matrix method as well. The suggested sensor is designed for monitoring the salinity of water by detecting the concentration of NaCl solution through near-infrared (IR) wavelengths. The reflectance numerical analysis showed the Tamm plasmon resonance. As the water cavity is filled with NaCl of concentrations ranging from 0 g l-1 to 60 g l-1, Tamm resonance is shifted towards longer wavelengths. Furthermore, the suggested sensor provides a relatively high performance compared to its photonic crystal counterparts and photonic crystal fiber designs. Meanwhile, the sensitivity and detection limit of the suggested sensor could reach the values of 24 700 nm per RIU (0.576 nm (g l)-1) and 0.217 g l-1, respectively. Therefore, the suggested design could be of interest as a promising platform for sensing and monitoring NaCl concentrations and water salinity as well.

Hybrid Tamm plasmon resonance excitation towards a simple and efficient biomedical detector of NaI solution.

This work presents a theoretical verification for the detection of Sodium iodide (NaI) solution with different concentrations in the vicinity of Tamm plasmon (TP) resonance. The proposed sensing tool is constituted of {prism/Ag/cavity/(GaN/CaF2)15/air}. The essential foundation of this study is based on the displacement of the TP resonance by varying the concentration of an aqueous solution of sodium iodide (NaI) that fills the cavity layer. The resonant TP dip is shifted downwards the shorter wavelengths with the increment of the Ag layer thickness. Nevertheless, the resonant TP dip is shifted upwards to longer wavelengths with the increment of NaI refractive index/concentration. Also, the sensitivity of the sensing tool decreases with the increment of the NaI refractive index. However, the minimum result is not less than the value of 9913 nm RIU-1 for a concentration of 25%. Finally, the performance of our sensor in the form of the quality factor, detection limit, and figure of merit showed significant improvements in designing a high-performance liquid and biosensor.

Development of a Highly Efficient Optoelectronic Device Based on CuFeO2/CuO/Cu Composite Nanomaterials.

Herein, an optoelectronic device synthesized from a CuFeO2/CuO/Cu nanocomposite was obtained through the direct combustion of Cu foil coated with Fe2O3 nanomaterials. The chemical, morphological, and optical properties of the nanocomposite were examined via different techniques, such as XRD, XPS, TEM, SEM, and UV/Vis spectrophotometer. The optical reflectance demonstrated a great enhancement in the CuFeO2 optical properties compared to CuO nanomaterials. Such enhancements were clearly distinguished through the bandgap values, which varied between 1.35 and 1.38 eV, respectively. The XRD and XPS analyses confirmed the chemical structure of the prepared materials. The produced current density (Jph) was studied in dark and light conditions, thereby confirming the obtained optoelectronic properties. The Jph dependency to monochromatic wavelength was also investigated. The Jph value was equal to 0.033 mA·cm-2 at 390 nm, which decreased to 0.031 mA·cm-2 at 508 nm, and then increased to 0.0315 mA·cm-2 at 636 nm. The light intensity effects were similarly inspected. The Jph values rose when the light intensities were augmented from 25 to 100 mW·cm-2 to reach 0.031 and 0.05 mA·cm-2, respectively. The photoresponsivity (R) and detectivity (D) values were found at 0.33 mA·W-1 and 7.36 × 1010 Jones at 390 nm. The produced values confirm the high light sensitivity of the prepared optoelectronic device in a broad optical region covering UV, Vis, and near IR, with high efficiency. Further works are currently being designed to develop a prototype of such an optoelectronic device so that it can be applied in industry.

Activated carbon derived from sugarcane and modified with natural zeolite for efficient adsorption of methylene blue dye: experimentally and theoretically approaches.

The introduction of activated carbon/natural zeolite (AC/NZ) as an efficient and reliable nanoadsorbent for enhancing methylene blue (MB) dye adsorption. By calcining sugarcane waste at various temperatures between 500 and 900 °C, activated carbons (ACs) are formed. Both XRD and SEM were used for the characterization of the prepared adsorbents. Adsorption measurements for the removal of MB dye were made on the impact of pH, beginning MB concentration, and contact time. The maximum AC500/NZ adsorption capacity for MB dye at 25 °C, pH 7, and an AC500/NZ mass of 50 mg was found to be approximately 51 mg/g at an initial concentration of 30 ppm. The pseudo-second-order kinetics model and the Temkin isotherm model describe the adsorption process. The Temkin model shows that the adsorption energy is 1.0 kcal/mol, indicating that the MB-to-AC500/NZ adsorption process occurs physically. Our Monte Carlo (MC) simulation studies supported our findings and showed that the Van der Waals dispersion force was responsible for the MB molecule's physical adsorption. The AC500/NZ adsorbent is thought to be a strong contender for water remediation.

Conversion of Sewage Water into H2 Gas Fuel Using Hexagonal Nanosheets of the Polyaniline-Assisted Deposition of PbI2 as a Nanocomposite Photocathode with the Theoretical Qualitative Ab-Initio Calculation of the H2O Splitting.

This study is very promising for providing a renewable enrgy (H2 gas fuel) under the elctrochemical splitting of the wastwater (sewage water). This study has double benefits: hydrogen generation and contaminations removel. This study is carried out on sewage water, third stage treated, from Beni-Suef city, Egypt. Antimony tin oxide (ATO)/polyaniline (PANI)/PbI2 photoelectrode is prepared through the in situ oxidative polymerization of PANI on ATO, then PANI is used as an assistant for PbI2 deposition using the ionic adsorption deposition method. The chemical structural, morphological, electrical, and optical properties of the composite are confirmed using different analytical tools such as X-ray diffreaction (XRD), scanning electron microscope (SEM), transmision electron microscope (TEM), Fourier-transform infrared spectroscopy (FTIR), and UV-Vis spectroscopy. The prepared PbI2 inside the composite has a crystal size of 33 nm (according to the peak at 12.8°) through the XRD analyses device. SEM and TEM confirm the hexagonal PbI2 sheets embedded on the PANI nanopores surface. Moreover, the bandgap values are enhanced very much after the composite formation, in which the bandgap values for PANI and PANI/PbI2 are 3 and 2.51 eV, respectively. The application of ATO/PANI/PbI2 nanocomposite electrode for sewage splitting and H2 generation is carried out through a three-electrode cell. The measurements carreid out using the electrocehical worksattion under th Xenon lamp (100 mW.cm-2). The produced current density (Jph) is 0.095 mA.cm-2 at 100 mW.cm-2 light illumination. The photoelectrode has high reproducibility and stability, in which and the number of H2 moles is 6 µmole.h-1.cm-1. The photoelectrode response to different monochromatic light, in which the produced Jph decreases from 0.077 to 0.072 mA.cm-2 with decreasing of the wavelengths from 390 to 636 nm, respectively. These values confirms the high response of the ATO/PANI/PbI2 nanocomposite electrode for the light illuminaton and hydrogen genration under broad light region. The thermodynamic parameters: activation energy (Ea), enthalpy (ΔH*), and entropy (ΔS*) values are 7.33 kJ/mol, -4.7 kJ/mol, and 203.3 J/mol.K, respectively. The small values of ΔS* relted to the high sesnivity of the prepared elctrode for the water splitting and then the hydrogen gneration. Finally, a theoretical study was mentioned for calculation geometry, electrochemical, and thermochemistry properties of the polyaniline/PbI2 nanocomposite as compared with that for the polyaniline.

Facile Fabrication of Polyaniline/Pbs Nanocomposite for High-Performance Supercapacitor Application.

In this work, a polyaniline/lead sulfide (PANI/PbS) nanocomposite was prepared by combining the in situ oxidation polymerization method and the surface adsorption process. This nanocomposite was applied as a supercapacitor electrode. The crystal structure, nanomorphology, and optical analysis of PANI and PANI/PbS were investigated. The electrochemical performance of the designed PANI/PbS electrode-based supercapacitor was tested by using cyclic voltammetry (CV), chronopotentiometry (CP), and AC impedance techniques in HCl and Na2SO4 electrolytes. The average crystallite size of the PANI/PbS nanocomposite is about 43 nm. PANI/PbS possesses an agglomerated network related to PANI with additional spherical shapes from PbS nanoparticles. After the PANI/PbS nanocomposite formation, there are enhancements in their absorption intensities. At a current density of 0.4 A g-1, the specific capacitance of PANI/PbS in Na2SO4 and HCl was found to be 303 and 625 F g-1, respectively. In HCl (625 F g-1 and 1500 mF cm-2), the gravimetric and areal capacitances of the PANI/PbS electrode are nearly double those of the Na2SO4 electrolyte. Also, the average specific energy and specific power density values for the PANI/PbS electrode in HCl are 4.168 Wh kg-1 and 196.03 W kg-1, respectively. After 5000 cycles, the capacitance loses only 4.5% of its initial value. The results refer to the high stability and good performance of the designed PANI/PbS as a supercapacitor electrode.

Fabrication of TiO2/NiO p-n Nanocomposite for Enhancement Dye Photodegradation under Solar Radiation.

A p-n nanocomposite based on TiO2 nanotubes (NTs) and NiO nanoparticles (NPs) was designed and optimized in this study to improve the photocatalytic performance of methylene blue (MB). The hydrothermal technique has been used to produce TiO2/NiO nanocomposites with different NiO NPs weight ratios; 1TiO2:1NiO, 1TiO2:2NiO, and 1TiO2:3NiO. The crystal phase, chemical composition, optical properties, and morphology of TiO2/NiO were explored by various techniques. TiO2 NTs have a monoclinic structure, while NiO NPs have a cubic structure, according to the structural study. The bandgap of TiO2 NTs was reduced from 3.54 eV to 2.69 eV after controlling the NiO NPs weight ratio. The TiO2/2NiO nanocomposite showed the best photodegradation efficiency. Within 45 min of solar light irradiation, the efficiency of MB dye degradation using TiO2/2NiO hits 99.5% versus 73% using pure TiO2 NTs. Furthermore, the catalytic photodegradation efficiency did not deteriorate significantly even after five reusability cycles, intimating the high stability of the TiO2/2NiO nanocomposite. This suggests that the loading of NiO NPs into TiO2 NTs lowers the recombination of photo-produced electron/hole pairs and enlarged solar spectral response range, which results in improved photocatalytic activity. The mechanism of charge transfer in the TiO2/NiO and kinetic models were discussed for the photodegradation of MB.

Glucose sensor modeling based on Fano resonance excitation in titania nanotube photonic crystal coated by titanium nitride as a plasmonic material.

The brilliant optical properties of plasmonic metal nitrides improve many applications. Modeling of light-confining Fano resonance based on a titanium nitride (TiN)-coated titanium oxide one-dimensional photonic crystal is investigated as a glucose sensor. There is a cavity layer filled with a glucose solution between the TiN thin layer and photonic crystals. The reflection spectrum is calculated numerically by using Bruggeman's effective medium approximation and transfer matrix method. The effect of plasmonic layer thickness, cavity layer thickness, and the thicknesses of the titanium oxide nanotube layers are optimized to achieve a high performance sensor. The result shows that the Fano resonances shift to higher wavelengths with increasing glucose concentration. The best sensitivity of the optimized biosensor is about 3798.32 nm/RIU. Also, the sensor performance parameters such as the limit of detection, figure of merit, and quality factor are discussed. The proposed sensor can be of potential interest due to its easy fabrication and higher performance than many previous reported sensors in the sensing field.

Effect of Au Plasmonic Material on Poly M-Toluidine for Photoelectrochemical Hydrogen Generation from Sewage Water.

This study provides H2 gas as a renewable energy source from sewage water splitting reaction using a PMT/Au photocathode. So, this study has a dual benefit for hydrogen generation; at the same time, it removes the contaminations of sewage water. The preparation of the PMT is carried out through the polymerization process from an acid medium. Then, the Au sputter was carried out using the sputter device under different times (1 and 2 min) for PMT/Au-1 min and PMT/Au-2min, respectively. The complete analyses confirm the chemical structure, such as XRD, FTIR, HNMR, SEM, and Vis-UV optical analyses. The prepared electrode PMT/Au is used for the hydrogen generation reaction using Na2S2O3 or sewage water as an electrolyte. The PMT crystalline size is 15 nm. The incident photon to current efficiency (IPCE) efficiency increases from 2.3 to 3.6% (at 390 nm), and the number of H2 moles increases from 8.4 to 33.1 mmol h-1 cm-2 for using Na2S2O3 and sewage water as electrolyte, respectively. Moreover, all the thermodynamic parameters, such as activation energy (Ea), enthalpy (ΔH*), and entropy (ΔS*), were calculated; additionally, a simple mechanism is mentioned for the water-splitting reaction.

Synthesis and Characterization of NiCoPt/CNFs Nanoparticles as an Effective Electrocatalyst for Energy Applications.

In this work, three nanoparticle samples, Ni4Co2Pt/CNFs, Ni5CoPt/CNFs and Ni6Pt/CNFs, were designed according to the molar ratio during loading on carbon nanofibers (CNFs) using electrospinning and carbonization at 900 °C for 7 h in an argon atmosphere. The metal loading and carbon ratio were fixed at 20 and 80 wt%, respectively. Various analysis tools were used to investigate the chemical composition, structural, morphological, and electrochemical (EC) properties. For samples with varying Co%, the carbonization process reduces the fiber diameter of the obtained electrospun nanofibers from 200-580 nm to 150-200 nm. The EDX mapping revealed that nickel, platinum, and cobalt were evenly and uniformly incorporated into the carbonized PVANFs. The prepared Ni-Co-Pt/CNFs have a face-centered cubic (FCC) structure with slightly increased crystallite size as the Co% decreased. The electrocatalytic properties of the samples were investigated for ethanol, methanol and urea electrooxidation. Using cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance measurements, the catalytic performance and electrode stability were investigated as a function of electrolyte concentration, scan rate, and reaction time. When Co is added to Ni, the activation energy required for the electrooxidation reaction decreases and the electrode stability increases. In 1.5 M methanol, the Ni5CoPt/CNFs electrode showed the lowest onset potential and the highest current density (30.6 A/g). This current density is reduced to 28.2 and 21.2 A/g for 1.5 M ethanol and 0.33 M urea, respectively. The electrooxidation of ethanol, methanol, and urea using our electrocatalysts is a combination of kinetic/diffusion control limiting reactions. This research provided a unique approach to developing an efficient Ni-Co-Pt-based electrooxidation catalyst for ethanol, methanol and urea.