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Building up and an investigating the efficiency of the cost-effective modified graphite for hybrid supercapacitor application is fascinating due to an extraordinary performance of graphite in battery application in day-to-day life about past decades. The metal oxides (Fe, Co, Ni) embedded in graphite was synthesized through the facile ultrasonication-assisted technique. Fe–Co–Ni deposited on graphite (Fe–Co–Ni-G) was studied structurally and morphologically by fourier transform infrared spectroscopy, X-ray diffraction analysis, field emission scanning electron microscopy, and high resolution transmission electron microscopy analyses. The electrochemical studies such as cyclic voltammetry, Galvanostatic charge–discharge analysis, and electrochemical impedance spectroscopy (EIS) analysis were revealed the supercapacitor performance of Fe–Co–Ni-G composite. The superior calculated areal capacitance of Fe–Co–Ni-G was 1355 mF cm−2 at 2 mA cm−2 which was higher than single metal deposited graphite (Fe-G 490 mF cm−2 at 2 mA cm−2) composite. EIS study supported the higher diffusion process of Fe–Co–Ni-G directed to higher supercapacitor performance that is possible for day-to-day life applications. [ABSTRACT FROM AUTHOR]

Lanthanum doped magnesium-zinc spinel ferrite samples were synthesized by the simple co-precipitation method with composition M g 0.5 Z n 0.5 F e 2 − x L a x O 4 (x = 0,0.025,0.05,0.075 a n d 0.1). The synthesized ferrite samples were investigated using by powder X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM) coupled with energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HR-TEM), electron paramagnetic resonance spectroscopy (EPR) and vibrating sample magnetometer (VSM). The effect of the La3+ ion doping on the crystallite size and lattice parameter of the material has been discussed. The crystallite size for all the samples were found to be in the range of 7–12 nm. The percentage porosity and percentage crystallinity of all the samples were found to be in the range of 49–50% and 80–85% respectively. In the frequency region of 400–600 cm−1 two absorption bands attributed to the T d and O h sites of the spinel ferrite have been observed. FTIR band spectra shift from lower to higher region with La3+ ion doping. Agglomeration of the particles is observed in the FE-SEM and HR-TEM images. Additional impurities except carbon are not present in the sample which is confirmed by EDS analysis. EPR analysis shows a decrease in the g-value from 2.18 to 2.12 for the synthesized samples with La3+ ion doping. The resonance field for synthesized sample shifts to higher magnetic field which may be due to ferromagnetic interaction caused by La3+ ion doping. The maximum spin concentration (1.508 × 1021 spin/g) and the relaxation time (4.132 × 10−11 s−1) was observed for the MZL2 composition. Magnetization curve shows the typical superparamagnetic nature of synthesized samples. The calculated squareness value of the synthesized sample refers to the magnetostatic interaction among particles. The obtained coercive field value is low which makes these materials suitable for ferrofluids and hyperthermia treatment applications. [ABSTRACT FROM AUTHOR]

Herein, we investigated the effect of the support modification (Sibunit carbon) with diazonium salts of Pd and Pd-Au catalysts on furfural hydrogenation under 5 bars of H2 and 50 °C. To this end, the surface of Sibunit (Cp) was modified with butyl (Cp-Butyl), carboxyl (Cp-COOH) and amino groups (Cp-NH2) using corresponding diazonium salts. The catalysts were synthesized by the sol immobilization method. The catalysts as well as the corresponding supports were characterized by Fourier transform infrared spectroscopy, N2 adsorption-desorption, inductively coupled plasma atomic emission spectroscopy, high resolution transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, Hammet indicator method and X-ray photoelectron spectroscopy. The analysis of the results allowed us to determine the crucial influence of surface chemistry on the catalytic behavior of the studied catalysts, especially regarding selectivity. At the same time, the structural, textural, electronic and acid–base properties of the catalysts were practically unaffected. Thus, it can be assumed that the modification of Sibunit with various functional groups leads to changes in the hydrophobic/hydrophilic and/or electrostatic properties of the surface, which influenced the selectivity of the process. [ABSTRACT FROM AUTHOR]

Graphene nanosheets (GNSs)/Al 2 O 3 composites were synthesized by wet milling. In this study, the effects of wet milling speed on the layer distribution, quality and conversion efficiency of graphene in GNSs/Al 2 O 3 composites were studied using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), raman spectroscopy, fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results show that the intensity of graphite peak decreases and the conversion efficiency of graphene increases with the increase of rotational speed in the range of 200–300 rpm, and a small amount of graphene coated Al 2 O 3 nanoparticles were found in GNSs/Al 2 O 3 composites. The number of layers (≤10 layers) of GNSs gradually increases with the increase of ball milling speed. When the rotational speed is 300 rpm, the graphene conversion efficiency is the highest. At different rotational speeds, graphene defects were the least influential marginal defects. There was no characteristic peak of graphene oxide (GO) appeared in the composite, indicating a small oxidation degree of graphene. [ABSTRACT FROM AUTHOR]

Photocatalytic activity of (CuO-Cu 2 O)Cu/ZnO hetero-junction nanocomposites along with their luminescent, biological applications in the progress of anticancer and antibacterial agents is investigated. The Cu and Zn bi-components modified (CuO-Cu 2 O)Cu/ZnO nanocomposites were synthesized via facile combustion route in the presence of controlled fuel to oxidizer ratio and were characterized by X-Ray Diffraction (XRD) patterns, Transmission electron microscopy (TEM), High resolution Transmission electron microscopy (HRTEM), Scanning Electron Microscopy (SEM), X-ray photoelectron Spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) and energy dispersive X-ray (EDX) analysis. The PL and UV–Visible diffused reflectance spectral (UV–Vis-DRS) techniques were used to measure the optical sensitivity and tuning of band gap in the samples. The excellent photocatalytic degradation of Methylene Blue and industrial waste water under Sunlight irradiation depends on the mass ratios of Cu/Zn. The findings show that the addition of a certain proportion of CuO, Cu 2 O, ZnO, and Cu can promote efficiency in Sunlight harvesting and separation of charge carriers. Process parameters namely catalyst quantity, dye concentration and a proposal for the mechanism of degradation pathway, experiments for trapping and enhancer are investigated. The study of photoluminescence, CIE and CCT calculations suggests that the present nanocomposite may find applications as phosphor material in warm white LEDs. The second segment of this study deals with the investigation of antibacterial performance of composites upon Gram-negative and Gram-positive bacteria. The results indicate that nanocomposites can be used in antibacterial control systems and as an important growth inhibitor in various microorganisms. The cytotoxic effect of the (CuO-Cu 2 O)Cu/ZnO (CCCZ11) nanocomposite was determined by colorimetric and flow cytometric cell cycle analysis. Our experimental results show that the nanocomposite can induce apoptosis and suppress the proliferation of HeLa cells. The applications of nanocomposites based on Cu, an abundant and inexpensive metal has created much interest in various multifunctional applications. [ABSTRACT FROM AUTHOR]

In the present study, mixed calcium magnesium oxide (CaMgO 2) nanoflakes were synthesized using an ultrasound-assisted co-precipitation method. The physicochemical, structural and functional properties and elemental composition of the nanoflakes had been characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), High-resolution transmission electron microscopy (HR-TEM), Fourier Transform Infrared spectroscopy (FTIR), UV–VIS spectroscopy, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Moreover, the photocatalytic actions of the nanoflakes were evaluated by the removal rates of methylene blue (MB) and p -nitrophenol (4-NP) under UV irradiation at room temperature. SEM-EDS studies revealed that the nanoflakes consisted of mixed oxide such as magnesium oxide (MgO) and calcium oxide (CaO) particles. The size of the nanoflakes was found to be in the range of 10–30 nm and the average size was 25 nm as confirmed by HR-TEM analysis. XRD revealed that the standard crystal size was calculated to be 25 nm. The synthesized nanoflakes had a strong photocatalytic activity for methylene blue (MB) and p -nitrophenol (4-NP) degradation in the presence of H 2 O 2 under UV light irradiation within 60 min and 30 min, respectively. Hence, the present study proposes that the CaMgO 2 nanoflakes can be employed for the removal of dyes from wastewater. [ABSTRACT FROM AUTHOR]

This paper deals with adsorption behavior of ruthenium on Tri-n-butyl phosphate functionalized Multi Walled Carbon Nanotubes (MWCNTs-COO-TBP) from aqueous solution. Adsorption method is significant for trace levels (expected level) removal of ruthenium in bioassay (urine) samples which is mandatory requirement of radiation workers in nuclear environment. Multi Walled Carbon Nanotubes (MWCNTs) were initially converted to carboxylated Multi Walled Carbon nanotubes (MWCNTs-COOH) and subsequently treated with Tri-n-butyl phosphate to MWCNTs-COO-TBP. The synthesized MWCNTs-COOH and MWCNTs-COO-TBP were confirmed by Fourier Transform Infrared Spectroscopy (FTIR). Spectroscopic and microscopic techniques such as X-Ray Diffraction (XRD), Raman Spectroscopy, Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS) and High Resolution Transmission Electron Microscopy (HR-TEM) were used for its characterization before and after adsorption. Various adsorption parameters such as contact time, pH, metal ion concentration and temperature were studied. Langmuir adsorption isotherm model and Pseudo second order kinetics model were found to be best fitted in terms of standard deviation and regression coefficient. Thermodynamics parameters such as enthalpy (ΔH°), entropy (ΔS°), Gibbs energy (ΔG°), activation energy (E a) and sticking probability (SP*) were calculated. The adsorption capacity was calculated and found to be 141.23 mg.g−1.Moreover, quantification of defects, strains with charge doping states were calculated from Raman mapping and correlation plot. [Display omitted] • Synthesis and characterization of Tri-n-Butyl Phosphate functionalized Multi Walled Carbon Nanotubes (MWCNTs-COO-TBP). • Detailed study on adsorption of ruthenium on MWCNTs-COO-TBP and its kinetics, thermodynamics and isotherm. • Functionalization of MWCNTs by TBP and its adsorption for ruthenium, confirmed by FTIR and EDS analysis. • Quantification of defects and strains with charge doping states were calculated from Raman mapping and correlation plot. • The potential application of MWCNTs-COO-TBP for adsorption of Ru from aqueous solution was explored. [ABSTRACT FROM AUTHOR]

For environmental reasons, the paints industry shifts from solvent-borne towards water-borne formulations. This change is challenging the business of aluminum pigments, as the hydrogen released by the reaction of aluminum with water degrades the optical properties, besides being a safety concern. In this work, industrial-grade aluminum pigments are encapsulated, by a well-known method, in a silica matrix by sol-gel process using isopropanol - a more suitable solvent for the industry. The effectiveness of the encapsulation process is proven by advanced physical methods (Scanning Electron Microscopy, Energy Dispersive X-Ray Analysis, Selected Area Electron Diffraction, Fourier Transformed InfraRed Spectroscopy, Thermo-Gravimetric Analysis) and by industry-relevant tests (stability in water, hiding power, flop and granulometry). Moreover, advanced surface-applied physical methods (High Resolution Transmission Electron Microscopy combined with Selected Area Electron Diffraction and Scanning Transmission Electron Microscopy, and FT-IR microscopy) clearly show the homogeneity of the resulting pigments, a quality which is highly desirable for practical applications. The results demonstrate that stability comparable to that of pigments passivized by chromium-based inhibitors is easily achieved, for a variety of operating conditions. However, accomplishing a homogeneous silica layer of the right thickness is the determining factor for good optical properties. [ABSTRACT FROM AUTHOR]

The dispersion stability of aqueous suspensions containing silicon nitride nanopowder prepared by direct nitridation had been studied. The Si 3 N 4 powder was calcined at 200 °C, 400 °C and 600 °C, respectively. It was aimed to improve dispersion stability of Si 3 N 4 suspension, and the effects were evaluated by measuring the median diameters of the samples taken from the slurries after settling experiments. The relationship between the median diameter and the viscosity of the slurry was discussed on the basis of Stoke's law. High resolution transmission electron microscopy (HRTEM) clearly revealed that the calcined Si 3 N 4 particles were covered by an amorphous surface layer, which was mainly composed of silica. It can also be easily verified according to the results of X-ray photoelectron spectroscopy (XPS) analyses and diffuse reflectance Fourier transform infrared spectroscopy (DRTIFT) measurements. The formation of oxide layer also led to an increase in the total oxygen content of Si 3 N 4 powder. Inductively coupled plasma atomic emission spectrometry (ICP-OES) analyses showed that the soluble impurities decreased after thermal oxide process, which also contributed to the lower of viscosity according to Jones-Dole expression. Electrokinetic behavior of suspensions also indicated that the absolute value of ζ-potential increased after powder calcination. [ABSTRACT FROM AUTHOR]

The increasing demand of rare earth elements in agriculture and industry raises the potential environmental pollution with their inevitable toxicity and biological accumulation. It is necessary to develop an efficient and low-cost technique to effectively remove rare earth elements. N-doped carbon dots (CDs) were green-synthesized using one-pot domestic microwave oven and novel alginate composite (ALG@CDs) beads were fabricated by embedding the N-doped CDs into pure alginate hydrogel beads. The synthetic materials were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and zeta potential measurement. The ALG@CDs beads could effectively adsorb rare earth elements from aqueous solutions. Taking the adsorption of rare earth element Gd (III) as an example, initial concentration, adsorbent dosage, pH, temperature and contact time were optimized. The adsorption isotherms and kinetics fitted to Langmuir isotherm model (R2 > 0.9991) and pseudo-second-order kinetic model (R2 = 0.9918), respectively. The adsorption capacity of ALG@CDs-3 (201.21 mg/g) for Gd (III) was much higher than that of bare ALG beads (124.38 mg/g) according to the maximum theoretical adsorption capacity of Langmuir model. Competitive adsorption results indicated that ALG@CDs beads had stronger affinity to Gd (III) than to Al (III), Co (II), Ni (II), Zn (II), and Mg (II). The adsorbent could be easily collected and reused for five adsorption-regeneration cycles. The results indicated that the fabricated ALG@CDs beads are the promising materials for adsorption or enrichment of rare earth elements from waste water. [ABSTRACT FROM AUTHOR]

In this study, activated carbon (AC) and nano-zerovalent copper (nZVCu) functionalized hydroxyapatite (HA) and alginate beads were synthesized and used for the removal of As3+ from aqueous solution. The characterization by X-ray diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, high resolution transmission electron microscopy, BET surface area analysis, thermogravimetric analysis, and Fourier transform infrared spectroscopy revealed successful formation of the AC/nZVCu/HA-alginate, nZVCu/HA-alginate, AC/HA-alginate, and HA-alginate beads. The scanning electron microscopy and surface analysis revealed the prepared beads to be highly mesoporous which led to the maximum adsorption of As3+, i.e., 13.97, 29.33, 30.96, and 39.06 mg/g by HA-alginate, AC/HA-alginate, nZVCu/HA-alginate, and AC/nZVCu/HA-alginate beads, respectively. The thermogravimteric analysis showed the nZVCu/HA-alginate beads to be highly stable while the AC composite beads as the least stable to heat treatment. The HA-alginate beads achieved 39% removal of As3+, however, removal efficiency was promoted to 95% by coupling AC and nZVCu with HA-alginate beads at a reaction time of 120 min. The removal of As3+ by the prepared AC & nZVCu coupled HA-alginate beads was promoted with increasing [As3+] 0 and [AC/nZVCu/HA-alginate] 0. The pH of aqueous solution significantly influenced the removal of As3+ by AC/nZVCu/HA-alginate beads and maximum removal was achieved at pH 5.8. Freundlich adsorption isotherm and pseudo-second-order kinetic models were found to best fit the removal of As3+ by the synthesized beads. The high performance of AC/nZVCu/HA-alginate beads in the removal of As3+ even after seven cyclic treatment as well as least leaching of Cu ions into aqueous solution suggest enhanced reusability and stability of HA-alginate beads by coupling with AC and nZVCu. The results suggest that the synthesized beads have good potential for the removal of As3+ from aqueous solutions. Image 1 • Characterization techniques proved nZVCu and AC coupled HA-Alginate beads formation. • Coupling AC and nZVCu enhanced performance and reusability of HA-Alginate beads. • Removal of As3+ best fitted Freundlich isotherm and pseudo-second-order models. • Removal of As3+ was significantly affected by the pH of aqueous solution. [ABSTRACT FROM AUTHOR]

• Polyaniline and Tl 2 O 3 -SiO 2 /polyaniline have been successfully synthesized • Polyaniline and Tl 2 O 3 -SiO 2 /polyaniline showed substantial protection performances for C-steel in HCl • The incorporation of Tl 2 O 3 -SiO 2 nanoparticles with polyaniline improve its protection ability • SEM/EDX emphasizes film formation of Tl 2 O 3 -SiO 2 /polyaniline nanocomposite on the steel surface after immersion The current approach discussed a synthesis and characterization of polyaniline (PANI) and two modified loading of 5, 10% Tl 2 O 3 -SiO 2 / PANI, in which Tl 2 O 3 -SiO 2 nanoparticles (NPs) were modified with PANI forming nanocomposites. The composite formation and structure were confirmed by X-ray diffraction (XRD), UV–vis absorption spectra (UV–vis), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), High resolution transmission electron microscopy (HR-TEM), and dynamic light scattering (DLS) technique. The prepared polymer (PANI) and its nanocomposites (Tl 2 O 3 -SiO 2 /PANI) were examined as a corrosion protective layer for carbon steel in 2.0 N HCl at different temperature (30–60 °C) by different electrochemical methods including potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) measurements. PANI inhibited the corrosion of carbon steel, yielding maximum protection capacity of 89%, which were further increased to 96% by the modification with Tl 2 O 3 -SiO 2 nanocomposites. The SEM/EDX investigations confirmed the presence of Tl 2 O 3 -SiO 2 / PANI nanocomposites film covering the metal surface. [ABSTRACT FROM AUTHOR]

• CuWO 4 /rGO nanocomposite was synthesized using sonochemical method and characterized spectral and electrochemical techniques. • The modified CuWO 4 /rGO immobilized GCE shows a high electrocatalytic activity towards the oxidation of nicotine. • Amperometric technique is adopted to identify low detection of nicotine in the presence of cigarette and urine samples. A novel and selective electrochemical sensing of nicotine is studied using copper tungstate decorated reduced graphene oxide nanocomposite (CuWO 4 /rGO) nafion (Nf) immobilized GC electrode (GCE). The CuWO 4 /rGO nanocomposite is synthesized using sonication method and characterized by HR-TEM (High resolution transmission electron microscopy), SEM (Scanning electron microscopy), FT-IR (Fourier transform infrared spectroscopy), SAED (Selected area of electron diffraction pattern), XRD (X-ray diffraction), Raman spectroscopy, Thermo gravimetric analysis (TGA) and EDX (Energy dispersive X-ray diffraction) techniques. The CuWO 4 /rGO/Nf immobilized GCE shows better electrocatalytic response for the detection of nicotine as compared to bare GCE. A better selectivity and sensitivity is achieved using CuWO 4 /rGO/Nf immobilized GCE to detect 0.1 µM nicotine in the presence of 100-fold excess concentrations of different interferents. The present CuWO 4 /rGO/Nf immobilized GCE electrochemical sensor exhibits an ample range of sensing from 0.1 µM to 0.9 µM and the low detection limit is found to be 0.035 µM (S/N = 3). Comparable results are achieved for the determination of nicotine in various real samples such as cigarettes (Gold flake and Wills) and urine samples with improved recoveries. [ABSTRACT FROM AUTHOR]

This study was aimed on the eco-friendly synthesis of silver nanoparticles (AgNPs), reduced graphene oxide (rGO) and AgNPs decorated rGO (rGO/AgNPs) nanocomposite and appraisal of their bioactivities and toxicity. As-prepared nanomaterials were established through high resolution X-ray diffraction (HR-XRD), high resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, UV–Vis. spectroscopy and Fourier transform infrared spectroscopy (FT-IR). In this study, leaves extract, graphene oxide (GO) and rGO did not show antibacterial and anticancer activities; no significant embryo toxicity was recorded. On the other hand, AgNPs displayed good antibacterial and anticancer activities; however, higher toxic effects were observed even at the lowest test concentration (0.7 μg/ml). In case of rGO/AgNPs nanocomposite, significant antibacterial activity together with low cytotoxicity was noticed. Interestingly, the embryo toxicity of AgNPs was significantly reduced by rGO, implying the biocompatible nature of as-synthesized nanocomposite. Taken together, these results clearly suggest that rGO/AgNPs nano hybrid composite could be developed as the promising biomaterial for future biomedical applications. [Display omitted] • In this study, AgNPs, rGO and rGO/AgNPs composites were prepared. • AgNPs showed good antibacterial and anticancer activities. • However, higher toxicity was observed even at 0.7 μg/ml of AgNPs. • rGO/AgNPs displayed good antibacterial activity with low cytotoxicity. • Interestingly, the toxic effects of AgNPs were significantly reduced by rGO. [ABSTRACT FROM AUTHOR]

• Gd-Y co-doped BiVO 4 photocatalysts were synthesized by a surfactant free hydrothermal technique. • Co-doping modified the morphology of the photocatalysts. • The co-doped BiVO 4 photocatalysts exhibited promising dye degradation efficiency and stability. • A possible photocatalytic mechanism is proposed to understand the rationale behind the improved properties. [Display omitted] The development of metal oxide photocatalysts with improved dye degradation efficiency under natural sunlight is in increasing demand due to their superior chemical stability and cost effectiveness. In this context, Gd and Y co-doped BiVO 4 having the nominal compositions Bi 0.92 Gd x Y y VO 4 (0.06 ≤ x ≤ 0.08; 0 ≤ y ≤ 0.02) have been synthesized via a surfactant free hydrothermal technique. The structural characterizations by X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy confirmed a monoclinic to tetragonal phase transition induced by co-doping in BiVO 4. High resolution transmission electron microscopy images revealed successful synthesis of Gd and Y co-doped BiVO 4 with a very good crystallinity. The steady-state photoluminescence spectroscopy analysis indicated significant suppression of charge carrier recombination in the co-doped samples. Under simulated sunlight, Bi 0.92 Gd 0.07 Y 0.01 VO 4 photocatalyst demonstrated 94% degradation of methylene blue dye (MB) within 90 min of irradiation time, which is about 4 times higher than that of pristine BiVO 4 photocatalyst. This superior photocatalytic performance may be attributed to the synergistic effect of nanorod like shape of the synthesized materials, negative surface charge, and enhanced charge career lifetime of the Bi 0.92 Gd 0.07 Y 0.01 VO 4 photocatalyst. [ABSTRACT FROM AUTHOR]

Due to the widespread usage of hydrogen peroxide (H 2 O 2) in various consumer and industrial products (Examples: fuel cells and antibacterial agents), it became important to accurately detect H 2 O 2 concentration in environmental, medical and food samples. Herein, titanium carbide Ti 3 C 2 T x (MXene) was synthesized by using Ti, Al and C powders at high-temperature. Then, nanocrystalline iron oxide (α-Fe 2 O 3) was obtained from a single solid-phase method. Using Ti 3 C 2 T x and Fe 2 O 3 powders, Ti 3 C 2 T x -Fe 2 O 3 nanocomposite was prepared by ultrasonication. As-synthesized, Ti 3 C 2 T x -Fe 2 O 3 composite had been characterized by UV–Visible (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Raman spectroscopy. The Fe 2 O 3 nanoparticles (NPs) were decorated on the surface of Ti 3 C 2 T x as observed by high resolution scanning electron microscopy (HR-SEM) and high resolution transmission electron microscopy (HR-TEM). The Ti 3 C 2 T x nanosheets were formed with the average size of 400–500 nm. HR-SEM images of α-Fe 2 O 3 showed that the coral-like particles with the average length ~5 μm were obtained. The electrochemical properties of the individual (Ti 3 C 2 T x and α-Fe 2 O 3) and composite materials (Ti 3 C 2 T x -Fe 2 O 3) were investigated by cyclic voltammetry (CV). Ti 3 C 2 T x -Fe 2 O 3 nanocomposite modified electrode had exhibited potent electro-catalytic activity for H 2 O 2 reduction by reducing the overpotential about 320 mV and a linear response was recorded from 10 nM to 1 μM H 2 O 2. The optimization of various parameters such as material composition ratio, amount of catalyst, effects of pH, scan rate and interference effects with other biomolecules were carried out. In addition, the kinetic parameters such as rate constant, diffusion coefficient and the active surface area of the electrodes were calculated. Moreover, the Ti 3 C 2 T x -Fe 2 O 3 composite modified electrode was used successfully to detect H 2 O 2 in food and urine samples. We believe that Ti 3 C 2 T x -Fe 2 O 3 composite based materials could be used for the fabrication of non-enzymatic H 2 O 2 sensors for medical diagnosis, food safety and environmental monitoring applications. • We reported Ti 3 C 2 T x -Fe 2 O 3 composite for the electroanalysis of hydrogen peroxide (H 2 O 2). • Material composition, amount of catalyst and pH were optimized for the electro-reduction of H 2 O 2. • Ti 3 C 2 T x -Fe 2 O 3 showed a linear range of H 2 O 2 detection from 10 to 1000 nM with high selectivity. • The kinetic parameters such as active surface area, diffusion coefficient and rate constant were calculated. • The application of Ti 3 C 2 T x -Fe 2 O 3 modified electrode was demonstrated in food and urine samples with high accuracy. [ABSTRACT FROM AUTHOR]

As a widely used water-soluble azo dye, methyl blue has aroused widespread concern for its environmental problems. In this paper, magnetic nickel-magnesium ferrites were deemed as a promising dye adsorbent, and they could be synthesized through a rapid combustion process. The properties of the nanoparticles were acquired by the scanning electron microscope (SEM), the energy dispersive spectroscopy (EDS), the X-ray diffraction (XRD), the vibrating sample magnetometer (VSM), the high resolution transmission electron microscopy (HRTEM), the N 2 adsorption-desorption isotherms, and the Fourier transform infrared spectroscopy (FTIR). The structure analysis demonstrated that the average particle size of magnetic nickel-magnesium ferrites was 59.2 nm, the saturation magnetization was 34.1 A·m2/kg and the specific surface area was 94.69 m2/g. After investigating the ratio of nickel to magnesium and the key parameters affecting the properties of ferrites, the adsorption of methyl blue onto the nanoparticles was discussed. Adsorption kinetics and isotherm models were employed to fit the relevant data, and the adsorption capacity of nanoparticles on methyl blue reached 306.4 mg/g when the initial concentration of methyl blue was 900 mg/L. The effect of pH value on the adsorption was explored, and seven cycles of the sample were recorded. Subsequently, the cyclic voltammetry (CV) and the electrochemical impedance spectroscopy (EIS) curves of the nanoparticles before and after adsorption were measured. To sum up, nickel-magnesium ferrites had the advantages of low cost, magnetic separation, facile preparation, high adsorption efficiency, and reusability, which suggested it had a broad application prospect in the field of dye removal. Magnetic Ni x Mg (1−x) Fe 2 O 4 nanoparticles are prepared via a rapid combustion process, the experimental data of methyl blue onto Ni x Mg (1−x) Fe 2 O 4 nanoparticles are described by the pseudo-second-order adsorption kinetics and Langmuir adsorption isotherm model at room temperature, and the adsorption mechanism is discussed. Besides, the electrochemical performance of methyl blue onto magnetic Ni x Mg (1−x) Fe 2 O 4 nanoparticles before and after adsorption is analyzed by CV and EIS. [Display omitted] • Magnetic Ni x Mg (1−x) Fe 2 O 4 nanoparticles are prepared via a rapid-combustion process. • Adsorption mechanism of methyl blue onto Ni 0.9 Mg 0.1 Fe 2 O 4 nanoparticles is investigated. • Electrochemical performance of methyl blue onto nanoparticles is analyzed by CV and EIS. [ABSTRACT FROM AUTHOR]

The main purpose of this work was to quantify and characterize chemically and morphologically the emission of soot particles from the open burning of several common solid waste including paperboard, wood, peel, chemical fiber, polyethylene (PE) and polyvinyl chloride (PVC). The experiment was conducted in a laboratory-scale open-burning combustor with a dilution sampling system to obtain soot particles. The thermogravimetric profiles (TGA) showed an increasing order of oxidation reactivity: PE > PVC > fiber > paper ≈ peel > wood. High resolution transmission electron microscopy (HRTEM) images revealed more detailed information about the morphology and the particle size of soot aggregates. Subsequent quantification of nanostructure by fringe analysis showed that plastics generated soot particles with the looser carbon layers with higher tortuosity compared to the three kind of biomass. Raman spectroscopy further confirms the observed differences. In addition, wood soot exhibited the highest content of C–OH group (17.5%) among the six samples (X-Ray photoelectron spectroscopy, XPS), whereas PE and PVC soot exhibited the highest absorption peaks of aliphatic C–H groups (Fourier transform infrared spectroscopy, FTIR). Comparative analysis revealed that the interlayer distance was more important on the evaluation of reactivity than soot morphologies. The present work concluded that the physiochemical characteristics of soot particles releasing during open burning are strongly depending on waste composition and provided new data for the understanding of soot emissions from open burning. Image 1 • Physiochemical properties of soot from open waste burning were studied. • Soot samples showed varying morphologies and nanostructures. • Plastic soot was more reactive towards oxygen than biomass soot. • The interlayer distance was more important on the evaluation of reactivity. • Waste composition impacted the soot physical and chemical properties. [ABSTRACT FROM AUTHOR]

The effects of the wet milling rotating speed on the number of graphene layers and graphene quality, and the conversion efficiency of graphite exfoliate to graphene, were investigated by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results show that the number of few-layer graphene nanometer sheets (GNSs) (≤10 layers) gradually increases with the increase of rotational speed in the range of 160–240 rpm. The proportion of GNSs with 0–10 layers reaches more than 80% as the rotational speed is increased to 280 rpm. GNS defect types in the composite materials are marginal defects with minimal influence and almost no oxidation. In the range of 160–280 rpm, the intensity of graphite peak decreases and the conversion efficiency of graphene increases with the increase of rotational speed. This is the same as the experimental result obtained by HRTEM. [ABSTRACT FROM AUTHOR]

Tailoring the shape of nanoscale materials enables obtaining morphology-controlled surfaces exhibiting specific interactions with reactants during catalytic reactions. The specifics of nanoparticle surfaces control the catalytic performance, i.e., activity and selectivity. In this study, shape-controlled Platinum (Pt) and Palladium (Pd) nanoparticles with distinct morphology were produced, i.e., cubes and cuboctahedra for Pt and spheres and polyhedra/multiple-twins for Pd, with (100), (111 + 100), curved/stepped and (111) facets, respectively. These particles with well-tuned surfaces were subsequently deposited on a Zirconium oxide (ZrO2) support. The morphological characteristics of the particles were determined by high resolution transmission electron microscopy (HR-TEM) and X-ray diffraction (XRD), while their adsorption properties were investigated by Fourier transform infrared spectroscopy (FTIR) of CO adsorbed at room temperature. The effect of the nanoparticle shape and surface structure on the catalytic performance in hydrodechlorination (HDCl) of trichloroethylene (TCE) was examined. The results show that nanoparticles with different surface orientations can be employed to affect selectivity, with polyhedral and multiply-twinned Pd exhibiting the best ethylene selectivity. [ABSTRACT FROM AUTHOR]

The materials and substances required for sustainable water treatment by adsorption technique, are still being researched widely by distinguished classes of researchers. Thus, the need to synthesize substances that can effectively clean up pollutants from the environment cannot be overemphasized. So far, materials in bulk forms that are rich in carbon, such as biochar and varieties of activated carbon have been used for various adsorptive purposes. The use of bulk materials for such purposes are not efficient due to minimal surface areas available for adsorption. This study explores the adsorption task at nano dimension using carbon dots (CDs) from tapioca. The properties of carbon structure and its influence on the adsorptive efficacy of carbon nanoparticles were investigated by energy-dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HrTEM), and atomic force microscopy (AFM). The results implied carbon present in CDs are good adsorbents for effective adsorption of heavy metal ions (lead) with removal efficiency of 80.6% in aqueous environment. The adsorption process as explored by both Langmuir and Freundlich isotherms have proven favorability of the adsorption process. Langmuir form two and three have correlation coefficients R2 at 0.9922 and 0.9912, respectively. The Freundlich isotherm confirms CDs as having defined surface heterogeneity and the exponential distribution of active sites. The adsorption of lead unto CDs obeyed the second order kinetic model with coefficient of determination, R2 of 0.9668 and 0.9996 at an initial lead concentration of 20 mg/L and 100 mg/L, respectively. The findings validated the efficiency of CDs derived from tapioca as an excellent material for further utilization in the environmental fields of wastewater pollution detection and clean up, bio-imaging, and chemical sensing applications. [ABSTRACT FROM AUTHOR]

High-temperature carbonisation is used to prepare many traditional Chinese medicine charcoal drugs, but the bioactive haemostatic substances of these medicines and their mechanisms are still unknown. This study developed and evaluated nanoparticles (NPs) derived from Selaginella pulvinate Carbonisata (STC) for the first time. The haemostatic effect of STC-NPs prepared at 300, 350, and 400 °C were investigated in mouse tail amputation and liver scratch experiments. STC-NPs obtained at 400 °C had the strongest haemostatic effect, and were accordingly characterised by ultraviolet–visible spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, high resolution transmission electron microscopy, X-ray diffractometry, and X-ray photoelectron spectroscopy. STC-NPs averaged 1.4–2.8 nm and exhibited a quantum yield of 6.06% at a maximum excitation wavelength of 332 nm and emission at 432 nm. STC-NPs displayed low toxicity against mouse monocyte macrophage RAW 264.7 cells by CCK-8 assay, and STC-NP treatment significantly shortened bleeding time in rat and mouse models. Coagulation assays showed that the haemostatic effects of STC-NPs were related to improving the fibrinogen and platelet contents, as well as decreasing the prothrombin time that resulted from stimulating extrinsic blood coagulation and activating the fibrinogen system. The STC-NPs had remarkable haemostatic effects in the tail amputation and liver scratch models; these effects may be associated with the exogenous coagulation pathway and activation of the brinogen system, according to the evaluation of the mouse coagulation parameters. This novel evaluation supports the material basis of STC use in traditional Chinese medicine, and this article is worthy of study by authors of clinical pharmacy. [ABSTRACT FROM AUTHOR]

Herein we report a facile and cost-effective design for the fabrication of a new binary MnMoO 4 /NiFe 2 O 4 nanocomposite through co-precipitation and hydrothermal routes. The resulting nanomaterial was characterized using powder X-ray Diffraction Studies (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), High Resolution Transmission Electron Microscopy (HR-TEM), Vibrating Sample Magnetometry (VSM), X-ray Photoelectron Spectroscopy (XPS), UV–vis Diffuse Reflectance Spectroscopy (UV–vis DRS) and Photoluminescence (PL) techniques. Its efficiency as a photocatalyst was investigated in the degradation studies of some selected organic contaminants such as Methylene blue (MB), Rhodamine B (Rh B), Methyl Violet (MV) and Basic Fuchsin (BF) in aqueous medium under visible light. The as-synthesized photocatalyst showed superior photocatalytic performance with 96% efficiency for each of MB, Rh B and MV degradation and 95% BF removal efficiency. The stability of the magnetically recovered photocatalyst was then explored from its recyclability studies in the degradation of MB. The spent photocatalyst showed increased agglomerated forms of the synthesized MnMoO 4 /NiFe 2 O 4 nanostructures. [ABSTRACT FROM AUTHOR]

Functionalised mesoporous silica SBA-15 was designed to exhibit dual responsive behaviour by grafting poly [2- (N, N-dimethylamino) ethyl methacrylate] (PDMAEMA) via free radical polymerisation. For this, the SBA-15 was modified by 3-(trimethoxy silyl) propyl methacrylate (TMSPM) for allowing methacrylate functionality on the mesoporous surface for free radicle polymerisation (m-SBA-15). Temperature and pH responsive PDMAEMA were grafted on the well-ordered rod-like m-SBA-15. Monometallic palladium (Pd) nanoparticles (NPs) were then incorporated in the pre-synthesised m-SBA-15/PDMAEMA. The morphology and structure of resulting materials were characterised by powder X-ray diffraction, Fourier transform infrared spectroscopy, high resolution transmission electron microscopy, field emission scanning electron microscopy, thermogravimetric analysis, and nitrogen adsorption-desorption isotherms. The dual stimuli-responsive behaviour of the hybrid material was monitored by dynamic light scattering measurement. Synthesised materials were tested for their dual stimuli (pH and temperature)-responsive catalytic activity in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). It was observed that the catalytic activity of the Pd/m-SBA-15/PDMAEMA catalyst was significantly higher at a given pH and temperature than any of SBA-15 only without using PDMAEMA and Pd NPs, m-SBA-15 grafted with PDMAEMA without Pd NPs, or Pd NPs incorporated m-SBA-15 without grafting PDMAEMA. [ABSTRACT FROM AUTHOR]

The present study explores the feasibility of Sr–Ce based mixed metal oxides for its performance in transesterification reaction of waste cooking oil. The catalyst synthesis was carried out through gel combustion route and was characterized through several techniques including thermal analysis (TGA-DTA), X-ray diffraction (XRD), attenuated total reflectance based Fourier transform infrared spectroscopy (ATR-FTIR), high resolution scanning electron microscopy (HR-SEM) assisted with EDX, BET specific surface area and Hammett indicator basicity. The enhanced activity of the catalyst was investigated at pH 7.0 with Sr–Ce atomic ratio of 3:1 at 900 °C of calcination temperature. Influences of various process parameters on transesterification efficiency were carefully investigated. The experimental results demonstrated that maximum transesterification efficacy of 99.5% was achieved under optimized reaction conditions with catalyst dose of 2.0 wt %, oil-to-methanol ratio 1:14, reaction time 120 min, reaction temperature 65 °C and stirring speed of 700 rpm. For better interpretation of the process, the reaction rate was computed by employing pseudo-first and pseudo-second order kinetics model at varying reaction temperature (50 °C–75 °C). The transesterification data agreed well with pseudo-first order model with highest rate constant value of 2.5 × 10−3 min−1 was evaluated at 65 °C. Activation energy and frequency of the reaction was quantified from the Arrhenius expression as 17.04 kJ/mol and 9.92 min−1, respectively. Thermodynamic analysis of the reaction system suggests that the transesterification of the waste cooking oil followed endergonic reaction pathway. Synthesis of biodiesel was ascertained from the H1-NMR and FTIR analysis of the transesterified product, further, the physicochemical properties of the biodiesel were also compared with that of diesel fuel and the resultant values were found to be within ASTM limits. Reusability study was also conducted and it indicated that the catalyst can be easily regenerated and could be effectively reused up to four runs. • Feasibility of SrCe mixed metal oxide as a basic catalyst has been reported for the first time. • 99.5% methyl ester conversion was achieved. • Transesterification reaction was better elucidated in terms of pseudo-first order kinetics. • Catalyst exhibit commendable reusable property can be reuse for four times with efficiency more than 80%. • Synthesized biodiesel demonstrate moderate emission performance. [ABSTRACT FROM AUTHOR]

With increasing applications of metal-organic frameworks (MOFs) in the field of gas separation and catalysis, the preparation and performance research of encapsulating metal nanoparticles (NPs) into MOFs (M@MOF) have attracted extensive attention recently. Herein, an Ru@UiO-66 catalyst is prepared by a one-step method. Ru NPs are encapsulated in situ in the UiO-66 skeleton structure during the synthesis of UiO-66 metal-organic framework via a solvothermal method, and its catalytic activity for CO2 methanation with the synergy of cold plasma is studied. The crystallinity and structural integrity of UiO-66 is maintained after encapsulating Ru NPs according to the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). As illustrated by X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM), and mapping analysis, the Ru species of the hydration ruthenium trichloride precursor are reduced to metallic Ru NPs without additional reducing processes during the synthesis of Ru@UiO-66, and the Ru NPs are uniformly distributed inside the Ru@UiO-66. Thermogravimetric analysis (TGA) and N2 sorption analysis show that the specific surface area and thermal stability of Ru@UiO-66 decrease slightly compared with that of UiO-66 and was ascribed to the encapsulation of Ru NPs in the UiO-66 skeleton. The results of plasma-assisted catalytic CO2 methanation indicate that Ru@UiO-66 exhibits excellent catalytic activity. CO2 conversion and CH4 selectivity over Ru@UiO-66 reached 72.2% and 95.4% under 13.0 W of discharge power and a 30 mL·min−1 gas flow rate ( V H 2 : V C O 2 = 4 : 1 ), respectively. Both values are significantly higher than pure UiO-66 with plasma and Ru/Al2O3 with plasma. The enhanced performance of Ru@UiO-66 is attributed to its unique framework structure and excellent dispersion of Ru NPs. [ABSTRACT FROM AUTHOR]

A series of M x O y / SiO 2 (where M = Ni, Zn and Mn) nanocomposites were synthesized at different M x O y contents (0.2, 1 and 3 mmol per 1 g SiO 2) using a deposition method. The samples were characterized using nitrogen adsorption–desorption, X-ray diffraction, Fourier transform infrared spectroscopy, high resolution transmission electron microscopy and photon correlation spectroscopy. The heat of immersion in water ( Q w) and n-decane ( Q d) were measured using a microcalorimetry method, and the corresponding values of the hydrophilicity index K h = Q w / Q d were analysed. The formation of M x O y on a silica surface leads to diminishing of the Q w and Q d values (calculated per 1 g of nanocomposites) because of the specific surface area reduction. However, the Q w values calculated per 1 m 2 increase for Zn x O y / SiO 2 and Mn x O y / SiO 2 in comparison with the unmodified silica, and it remains unchanged for Ni x O y / SiO 2 . Silica modification with M x O y significantly changes the pH dependence of zeta potential and affects the surface charge density. A shift of the isoelectric point (pH IEP) and a character of the zeta potential ζ (pH) curve are affected by the M x O y phase, and pH IEP shifts toward higher values as follows Mn < Zn < Ni. [ABSTRACT FROM AUTHOR]

Mesoporous TiO2 containing different potassium content was prepared from potassium titanate by mediating the pH value of the ion exchange, which was used as catalytic support to load NiMo for hydrodesulfurization of dibenzothiophene. The as-prepared samples were characterized by X-ray diffraction, N2 physical adsorption/desorption, temperature-programmed reduction, scanning electron microscope/energy dispersive X-ray mapping analysis, high resolution transmission electron microscopy, and pyridine-adsorbed Fourier transform infrared spectroscopy. The characterization results showed that NiO and MoO3 were well dispersed on mesoporous TiO2 with varying potassium content. A crystal NiMoO4 phase was formed on the TiO2 with relatively high potassium content, which could decrease the reduction temperature of oxidized active species. The evaluation results from the hydrodesulfurization displayed that as the potassium content of the catalyst increased, the dibenzothiophene conversion firstly increased and then slightly decreased when potassium content exceeded 6.41 wt %. By contrast, the direct desulfurization selectivity could continuously increase along with the potassium content of catalyst. Furthermore, the change in direct desulfurization selectivity of a TiO2-supported NiMo catalyst was independent of the reaction condition. The mesoporous TiO2-supported NiMo catalyst incorporated with potassium could have near both 100% of dibenzothiophene and 100% of direct desulfurization selectivity. According to the structure–performance relationship discussion, the incorporation of potassium species could benefit the formation of more sulfided active species on mesoporous TiO2. Moreover, excessive free potassium species may poison the active sites of the hydrogenation pathway. Both factors determined the characteristics of complete hydrodesulfurization of dibenzothiophene via a direct desulfurization pathway for potassium-incorporated mesoporous TiO2 supported NiMo catalysts. [ABSTRACT FROM AUTHOR]