3D Modeling of Silver Doped ZrO2 Coupled Graphene-Based Mesoporous Silica Quaternary Nanocomposite for a Nonenzymatic Glucose Sensing Effects.

We described the novel nanocomposite of silver doped ZrO2 combined graphene-based mesoporous silica (ZrO2-Ag-G-SiO2,) in bases of low-cost and self-assembly strategy. Synthesized ZrO2-Ag-G-SiO2 were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, Nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), and Diffuse Reflectance Spectroscopy (DRS). The ZrO2-Ag-G-SiO2 as an enzyme-free glucose sensor active material toward coordinate electro-oxidation of glucose was considered through cyclic voltammetry in significant electrolytes, such as phosphate buffer (PBS) at pH 7.4 and commercial urine. Utilizing ZrO2-Ag-G-SiO2, glucose detecting may well be finished with effective electrocatalytic performance toward organically important concentrations with the current reaction of 9.0 × 10-3 mAcm-2 and 0.05 mmol/L at the lowest potential of +0.2 V, thus fulfilling the elemental prerequisites for glucose detecting within the urine. Likewise, the ZrO2-Ag-G-SiO2 electrode can be worked for glucose detecting within the interferometer substances (e.g., ascorbic corrosive, lactose, fructose, and starch) in urine at proper pH conditions. Our results highlight the potential usages for qualitative and quantitative electrochemical investigation of glucose through the ZrO2-Ag-G-SiO2 sensor for glucose detecting within the urine concentration.

Stabilizing decontamination foam using surface-modified silica nanoparticles containing chemical reagent: foam stability, structures, and dispersion properties.

The stabilization of decontamination foams containing a chemical reagent is a crucial requirement for their use in the decontamination of nuclear power plants. We have investigated the effects on decontamination foam stability of adding silica nanoparticles (NPs) modified with various functional groups, namely propyl (-CH3), amine (-NH2), and thiol (-SH) groups. The surface properties of these silica NPs were characterized with ATR-FTIR, solid NMR, and TGA analyses. We also established that the agglomeration in such foams of the amine-modified silica NPs is weaker than that of the other modified silica NPs due to their thorough dispersion in the liquid film. Further, the foam containing amine-modified silica NPs was found to be stable for 60 min at a pH of 2, i.e. under decontamination conditions. The bubble structure analysis showed that this decontamination foam has a bubble count that is approximately 5-8 times higher than the foams containing NPs modified with the other functional groups, which indicates that the decontamination foam with amine-modified silica NPs has the best foam structure of the three investigated foams. The well-dispersed and smaller amine-modified silica NPs enhance the foam stability by providing a barrier between the gas bubbles and delaying their coalescence. In contrast, the thiol- and propyl-modified silica NPs form aggregates with large diameters that reduce the maximum capillary pressure of coalescence and hence decrease the foam stability.

New Design of Active Material Based on YInWO4-G-SiO2 for a Urea Sensor and High Performance for Nonenzymatic Electrical Sensitivity.

In the present study, electrochemical sensing for urea was proposed utilizing graphene-based quaternary nanocomposites YInWO4-G-SiO2 (YIWGS). These YIWGS nanocomposites were utilized due to their exceptionally delicate determination of urea with the lowest detection limit (0.01 mM). These YIWGS composites were developed through a simple self-assembly method. From physical characterization, we found that the YIWGS composites are crystalline in nature (powdered X-ray diffraction), and Fourier transform infrared (FTIR) spectroscopy analysis provided the surface functionality and bonding. Scanning electron microscopy (SEM) studies indicated the morphology characteristics of the as-synthesized composites and the high-resolution transmission electron microscopy (HRTEM) image supported the formation of cubic or hexagonal morphology of the YIW nanocomposites. The YIWGS sensor showed a great electroanalytical sensing performance of 0.07 mM urea with a sensitivity of 0.06 mA cm-2, an expansive linear range of 0.7-1.5 mM with a linear response (R2 1/4 0.99), and an eminent reaction time of around 2 s. It also displayed a good linear response toward urea with negligible interferences from normal coinciding species in urine samples.

New modeling of 3D quaternary type BaCuZnS-graphene-TiO2 (BCZS-G-T) composite for photosonocatalytic hydrogen evolution with scavenger effect.

For the efficient evolution of hydrogen, we designed a 3D quaternary BaCuZnS-graphene-TiO2 (BCZS-G-T) composite by an ultrasonic method. Herein, we prepared a quaternary material to minimize the bandgap energy and size. We characterized the "as-prepared" composites by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, and electrochemical impedance spectroscopy (EIS). The high hydrogen evolution was attributed to the 3D quaternary BCZS-G-T composite with small bandgap energy because of its high photoelectron recombination properties. In addition, we demonstrated the combination effects with photocatalytic and sonocatalytic treatments with a scavenger. This work highlights the potential application of quaternary graphene-based composites in the field of energy conversion.

The surface modification and characterization of SiO2 nanoparticles for higher foam stability.

The surfactant and colloidal nanoparticles has been considered for various applications because of interaction of both complex mixtures. The hydrophilic SiO2 nanoparticle could not be surface active behavior at the liquid/air interface. In this study, the SiO2 nanoparticles have been modified with 3-isocyanatopropyltriethoxy-silane (ICP), and the effect of foam stability has been investigated. The physical properties of surface modified SiO2 nanoparticle were analyzed by XRD, TGA, FT-IR, and SEM. After surface modification of SiO2 nanoparticles, the contact angle of SiO2 nanoparticle was also increased from 62° to 82° with increased ICP concentration. The experimental result has shown that SiO2 nanoparticle with ICP was positive effect and improved foam stability could be obtained at proper ICP concentration compared with un-modified SiO2 nanoparticle.

Polypyrrole-Bonded Quaternary Semiconductor LiCuMo2O11-Graphene Nanocomposite for a Narrow Band Gap Energy Effect and Its Gas-Sensing Performance.

In this study, we demonstrate the fabrication and characterization of a new quaternary semiconductor nanocomposite of LiCuMo2O11/graphene oxide/polypyrrole (LCMGP) via a hydrothermal method and testing of an NH3 and H2SO4 sensor operating in gaseous states at room temperature. We used X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy to characterize the properties of LCMGP nanostructures. Our sensor is capable of detecting NH3 and H2SO4 and quantifying their concentration in the gas flow. These results have been confirmed by exposing the sensor to different concentrations of NH3 and H2SO4 (100-1000 ppm). The obtained results confirm the exceptional sensing properties of the graphene-polymer-combined quaternary semiconductor nanocomposite related to the oxidation-reduction process that can be used for detection, identification, and quantification purposes.

Hybrid of Graphene based on quaternary Cu2ZnNiSe4 -WO3 Nanorods for Counter Electrode in Dye-sensitized Solar Cell Application.

A novel nanohybrid of graphene-based Cu2ZnNiSe4 with WO3 nanorods (G-CZNS@W) was successfully synthesized via a simple hydrothermal method to use as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). The characterization technique confirmed the structural and morphologies of the G-CZNS@W nanohybrid, which could show rapid electrons transfer pathway through the WO3 nanorods. Moreover, the as-fabricated G-CZNS@W nanohybrid exhibited synergetic effect between G-CZNS and a WO3 nanorod, which could affect the electrocatalytic activity towards triiodide reaction. The nanohybrid exhibits an excellent photovoltaic performance of 12.16%, which is higher than that of the standard Pt electrode under the same conditions. The G-CZNS@W nanohybrid material as CE thus offers a promising low-cost Pt-free counter electrode for DSSC.

The double perovskite structure effect of a novel La2CuNiO6-ZnSe-graphene nanocatalytic composite for dye sensitized solar cells as a freestanding counter electrode.

Currently, the development of sensitized solar cells (DSSCs) with high power conversion efficiency and low cost is a major challenge in the academic and industrial fields. In order to enhance the current efficiency of dye-sensitized solar cells (DSSCs), a perovskite graphene-La2CuNiO6-ZnSe (G-LCN-ZS) as a counter electrode (CE) was introduced in this study via a conventional microwave treatment. A DSSC with 15% G-LCN-ZS CE achieved a high-power conversion efficiency up to 11.05% under AM 1.5G solar simulation, which is one of the highest reported efficiencies for ternary oxide-based graphene DSSCs. The G-LCN-ZS CE nanocomposites exhibit excellent catalytic activity towards the I3-/I- redox couple due to the positive synergistic effect between LCN-ZS nanoparticles and graphene sheets. Moreover, the graphene-based materials can provide a fast diffusion pathway for the electrolyte. In this paper, we have shown that alternative materials with high energy conversion efficiency can be used in future applications.