Search

For the first time, the BaTiO3 nano-sized particles were obtained through solid-state reaction by employing the titanium oxide nanoparticle. Meanwhile, by using TiO2 with micro-sized particles, the synthesized BaTiO3 shows the micro-sized. The XRD pattern confirms that both BaTiO3 nano-sized and micro-sized particles display the tetragonal structure. Both SEM and TEM analysis revealed that the size of the nano-sized material is in the range of 30–50 nm; in the meantime, the microsized material shows a size of 500 nm. The Eg of both BaTiO3 micro-sized and nano-sized were calculated by using the Kubelka-Munk function. The shifted bandgap of BaTiO3 nano-sized particle is nearly 0.24 eV larger than that of BaTiO3 miro-sized particle due to the particle size effect. The P-E measurement of n-BaTiO3 proved that the obtained BaTiO3 nano-sized is ferroelectric material. The result may provide a new route for the fabrication of barium titanate nanoparticle with ferroelectric properties.

Herein, MnO2@SiO2/C was produced from rice husk derived SiO2/carbon composite and MnO2 via hydrothermal method. The nanostructure gave good microstructural, morphological properties with highly catalytic properties. The hybrid catalyst comprising of MnO2@SiO2/C nanocomposite-supported gold nanoparticles was successfully fabricated by the novel solid grinding and tested for CO oxidation’s application. MnO2 nanoballs are 5 − 8 nm in diameter with a shell thickness of 1 nm, packing with laminar [MnO6] unit cells. The as-prepared gold catalysts containing 2wt% of Au loading, exhibited 50% CO conversion and a high specific activity of 0.21 molCO gAu−1 h−1 at 38 °C. MnO2@SiO2/C nanocomposite-supported gold nanoparticles were prepared by solid grinding using a non-volatile organogold(III) complex and rice husk. The catalysts showed high activity for CO oxidation.

g-C3N4@WO3.H2O nanoplate composite adsorbents were prepared in a simple acid precipitation method at room temperature. The g-C3N4@WO3.H2O nanoplate composite adsorbents were characterized by X-ray powder diffraction, micro-Raman spectroscopy, Fourier transform infrared spectra, scanning electron microscopy and UV-vis diffuse reflectance spectroscopy. The results show that the orthorhombic-phase WO3.H2O nanoplates with dimensions of [Formula: see text][Formula: see text]nm3 were successfully composited with g-C3N4. The methylene blue dye generation activity of these adsorbents was evaluated. The kinetics and absorption model of g-C3N4@WO3.H2O nanoplate composite adsorbents were further studied.

Supported nanomaterials can be used in a wide range of applications such as microelectronics, energy storage, sensors, sorbents, and catalysts due to their outstanding chemical and physical properties. In this work, we contribute a comprehensive review of a new fabrication method, sacrificial template-accelerated hydrolysis (STAH), for the synthesis of some typically supported nanomaterials. The report can be used to clearly understand the fabrication of nanomaterials using STAH method as well as the mechanism of the method, and the applications of the obtained nanomaterials.

In this work, we developed highly porous activated carbon (AC) materials with micro/meso porosity through carbonizing rice husk and treating them with K2CO3. Elemental sulfur was then loaded to the micropores through a solution infiltration method to form rice husk-derived activated carbon (RHAC)@S composite materials. The as-prepared RHAC@S composites with 0.25 mg cm−1 and 0.38 mg cm−1 of sulfur loading were tested as cathodes for lithium-sulfur (Li-S) batteries. The 0.25 mg cm−1 sulfur loaded sample showed an initial discharge capacity of 1080 mA h/g at a 0.1 C rate. After 50 cycles of charge/discharge tests at the current density of 0.2 C, the reversible capacity is maintained at 312 mA h/g. The RHAC material delivered a capacity of more than 300 mA h/g at a current density of 1.7 C. These results demonstrate that the RHAC porous materials are very promising as cathode materials for the development of high-performance Li-S batteries. Keywords: Rice husk, Cathode material, Carbonization process, Activated carbon, Lithium-sulfur batteries

This study synthesized cuprous oxide nanoparticles (Cu2O-ONPs) from the green precursors CuSO4.3H2O and Na2SO3. The materials samples were studied at prepared temperatures of 70 °C, 80 °C, 90 °C and 100 °C. The structure and characteristics of the materials were determined by methods such as Raman shift, UV-vis absorption spectrum, SEM, XRD. The results showed that, Cu2O-ONPs were crystallized the best in octahedral form at temperature of 90 °C. The absorption spectrum of the materials was in the visible light region \(\lambda \,\, \approx\) 500–600 nm with the band gap energy defined as Eg \(\approx\) 1.78–2.1eV. At calcination temperatures of 200 °C the materials retained the octahedral shape, but the absorption spectrum was shifted strongly in visible light region \(\lambda \,\, \approx\) 600–700 nm with Eg \(\approx\) 1.94eV. At the firing temperature of 300–400 °C the octahedral shapes of the materials were slightly distorted. At 500 °C the materials particles were inflated, broken and no longer retaining the original octahedral shape. Within this high temperature range of 300–500 °C the absorption spectra of the materials samples were shifted more strongly in visible light region \(\lambda \,\, \approx\) 800–900 nm, the optical band gap energy was reduced to a value Eg \(\approx\) 1.37–1.46eV which was due to the existence of two Cu2O-CuO phases. These will be desirable of material fabrication for applications in photochemical reactions in visible light region and other specific commercial applications that need further research and exploitation.

In this study, the electrochemical immunosensor for detecting Newcastle disease virus using the chicken egg yolk antibodies (IgY) was developed. The developed immunosensor was built into a three-electrode system consisting of two gold electrodes (a working electrode and a counter electrode) and a quasi-reference Ag/AgCl electrode. The IgY antibodies against Newcastle disease virus were immobilized on the working electrode (immunosensor) and the effect of the antibody concentration and virus incubation time on the output signal of the immunosensors was investigated. The investigation results show that when the antibody concentration was 60 µg/mL and the virus incubation time was 1 hour, the output signal of the immunosensors reached its maximum value (∆Ipeak = 0.1602). The detection limit of the sensors was 102 EID50/mL (EID50: 50% Empryo Infective Dose) at 25 oC. There was a good linear relationship between the ∆Ipeak and the logarithm of the virus Newcastle concentration in the range from 102 to 106 EID50/mL. The linear equation is ∆Ipeak = 0.0280logN – 0.00368 with the correlation coefficient of R2 = 0.9972.

In this paper, we present the results of the study of the effect of residual La on crystal structure, magnetic properties of La1+dFe11.05Si1.95 (d = 0.00; 0.03; 0.06 and 0.09) compounds. The analysis of X-ray diffractions showed that when the La content increases to 9%, the structure still remains cubic in a typical NaZn13 arrangement with unchanged lattice constant (about 0.5%). All compounds exhibit ferromagnetic - paramagnetic phase transitions. The Curie temperature TC increases slightly from 235 to 245 K.

LiMnxFe(1-x)PO4 olivine cathode material (x= 0.1; 0.2; 0.3 and 0.8) fabricated according to hydrothermal route. Micro-Raman spectroscopy, SEM scanning electron microscopy, UV-Vis absorption spectra and reflectance spectra methods were performed to study the characteristics of materials. The results showed that LiMnxFe(1-x)PO4 prepared materials were nano-meter in size (60-100 nm) and distorted sphere-like shape. The material has bands in the Raman spectrum corresponding to the position of the bands of the pure LiFePO4 and shift slightly. The band position at 410 cm-1 (corresponding to the position of the n2 band of the pure LiFePO4 sample) was attenuated of the sample in which Mn2+ ion content replaced Fe2+ ion content to 0.8 molar ratio. But the band position at 1020 cm-1 appeared with Strengthening intensity (corresponding to the position of the n3 band of the pure LiMnPO4 sample). The optical band gap energy of samples determined according to the Tauc equation in the range of 3.33-3.5 eV.

The rapid development of megacities, and their growing connectedness across the world is becoming a distinct driver for emerging disease outbreaks. Early detection of unusual disease emergence and spread should therefore include such cities as part of risk-based surveillance. A catch-all metagenomic sequencing approach of urban sewage could potentially provide an unbiased insight into the dynamics of viral pathogens circulating in a community irrespective of access to care, a potential which already has been proven for the surveillance of poliovirus. Here, we present a detailed characterization of sewage viromes from a snapshot of 81 high density urban areas across the globe, including in-depth assessment of potential biases, as a proof of concept for catch-all viral pathogen surveillance. We show the ability to detect a wide range of viruses and geographical and seasonal differences for specific viral groups. Our findings offer a cross-sectional baseline for further research in viral surveillance from urban sewage samples and place previous studies in a global perspective.