Assisted Solution Method Research Articles

Dimer-type Cs3Sb2I9: An efficient perovskite material for low operating voltage and high stability flexible resistive switching memory

All-inorganic perovskites have been taken as the promising functional materials in non-volatile resistive switching (RS) memory. Herein, the lead-free all-inorganic Cs3Sb2I9 perovskites with high stability are fabricated via hydrochloric acid (HCl) assisted solution method at low-temperature. The devices with a structure of Ag/polymethyl methacrylate (PMMA)/HCl-modified dimer-Cs3Sb2I9/ITO take on typical bipolar RS behavior and remarkable characteristics such as high ON/OFF ratio (≈66), low operating voltage (≈ −0.34 V/+0.25 V), excellent endurance property (≥120 cycles) and long data retention (≥104 s). Moreover, outstanding mechanical stability of the Cs3Sb2I9-based flexible memory devices are demonstrated under different bending angles and over consecutive 103 bending cycles. In addition, the Cs3Sb2I9-based memory devices show no obvious change in the RS behavior after over 10 days storage under an ambient atmosphere. This work will contribute to understanding the characteristics of low operating voltage and high stability RS behavior of the all-inorganic perovskites, and illuminate the great application potential of the lead-free antimony-based perovskite materials in next generation low power consumption non-volatile flexible memory devices.

Enhanced Productivity of Parabolic Solar Still Using -Mno2 Nano Particles

Parabolic solar still of area 0.25m2 is designed using mild steel and its enhanced productive yield with -MnO2 nanoparticles had been analyzed. Microwave assisted solution method have been used to synthesis α-MnO2 nanoparticles. XRD analysis of prepared -MnO2 nanoparticles size is found to be 35 nm. FTIR revealed the chemical composition and interaction of functional groups of MnO2 nanoparticles. SEM image shows the aggregates are mostly particles with random shapes. HRTEM image confirms the average particle size was around 35 nm. From the optical study it is inferred that the energy band gap value as 2.69 eV and the conductivity of prepared nanoparticles is found to be in the order of 10-7 S cm-1. Thermal stability of synthesized MnO2 nanoparticle has been analyzed with the help of TG study. Electrical conductivity of MnO2 have is in the order of 2.35×10 -7 Scm-1 as calculated from AC impedance spectroscopy. Heat Transfer phenomena under internal and external transfer modes along with thermophysical properties such as thermal conductivity, dynamic viscosity, density and latent heat of distillate yield is calculated. Instantaneous efficiency of parabolic solar still without and with MnO2 nanoparticles are found to be in the range of 11.52% to 40.71% and 10.94% to 46.32%. Similarly, overall efficiency is found to be 30.01% and 35.27%. The distillate productivity is mainly depended on the thermal parameters such as saturated vapor pressure and latent heat is observed as 8762 J/Kg, 9510 J/Kg, 2391875 Pa and 2388435 Pa for parabolic still in two modes of study.

Structural, Biological and Photocatalytic Properties of Zirconium Oxide Nanoparticles Synthesized by Microwave Assisted Solution Method

Zirconium dioxide nanoparticles have been synthesized by microwave assisted solution method. The prepared nanoparticle have been characterized by powder X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, ultraviolet- diffuse reflectance spectra, thermo gravimetric-differential thermal analysis and also evaluated for their antibacterial activity against bacterial strains. XRD pattern showed the prepared ZrO2 nanoparticles having monoclinic structure which shows the average crystalline size around 20 nm. SEM image showed the particles are spherical shape with agglomeration due to the intermolecular attraction for small particle size. From the UV-DRS,the energy band gap has found to be 4.9 eV. The results of antibacterial activity showed that the nanocrystalline zirconium dioxide had an important inhibitory activity against pseudomonas arginosa. Photocatalytic degradation of methylene blue dye in the presence of ZrO2 nanoparticle under sunlight has been investigated at various times. The 75 % of methylene blue dye has been degraded at 140 min of sunlight irradiation. The photocatalytic activity of catalyst has been high for 40 mg/50 mL sample concentration.

Synthesis and Investigation of Antimicrobial Activity of Tin Oxide Nanoparticles by Microwave Assisted Solution Method

Synthesis and Investigation of Antimicrobial Activity of Tin Oxide Nanoparticles by Microwave Assisted Solution Method

Largely enhanced near band edge emission of ultrathin zinc oxide nanowire/gold nanoparticles composites by surface plasmon resonance

Ultrathin zinc oxide nanowires with diameter less than 50nm were synthesized by polyethyleneimine assisted solution method. Zinc oxide nanowire near band edge emission was enhanced obviously by gold nanoparticles coating, and a max 26 times enhancement was realized. The defects caused visible light emission was also quenched to noise level when gold was deposited more than 10s. The large near band edge emission enhancement was caused by surface plasmon resonance mediated luminescent energy transfer, which absorbed the visible light energy and transferred to the near band edge emission. The large surface to volume ratio enhanced the coupling strength between gold nanoparticles and ultrathin zinc oxide nanowires. This research provide a method to improve the luminescent efficiency of zinc oxide nanowires.

PVP derived C/N coated SrLi2Ti6O14 as high performance anode material for lithium ion battery

Abstract SrLi 2 Ti 6 O 14 @C/N is synthesized by using a solid-state assisted solution method, with polyvinyl pyrrolidone (PVP) as carbon/nitrogen source. The morphology of SrLi 2 Ti 6 O 14 and SrLi 2 Ti 6 O 14 @C/N samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and elemental mappings. According to the results, C/N layer is uniformly coated on the surface of SrLi 2 Ti 6 O 14 . Subsequently, the two samples are analyzed by using electrochemical measurements such as galvanostatic charge/discharge tests, rate performance, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). SrLi 2 Ti 6 O 14 @C/N (initial charge capacity of 166.41 mAh g −1 ) shows enhanced electrochemical capability compared with SrLi 2 Ti 6 O 14 (156.06 mAh g −1 ). After 150 cycles, SrLi 2 Ti 6 O 14 @C/N can keep a reversible capacity of 156.58 mAh g −1 with only 5.98% capacity loss at 100 mA g −1 . The improvement is due to the increase of electronic conductivity and the decrease in the redox polarization after coating. Moreover, in-situ XRD is also used to investigate the structural stability of SrLi 2 Ti 6 O 14 @C/N. All the results prove that the C/N coating has a positive effect on the electrochemical performance of SrLi 2 Ti 6 O 14 .

Preparation and characterization of SrLi2Ti6O14@C/Ag as lithium storage anode material for rechargeable batteries

In this work, silver and carbon co-coated SrLi2Ti6O14 is synthesized by using a solid-state assisted solution method, with glucose as carbon source and silver nitrate as Ag source. The structural and morphological properties of as-prepared samples are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), which confirm that C/Ag composite layer is uniformly coated on the surface of SrLi2Ti6O14. Electrochemical measurements like galvanostatic charge/discharge tests, rate performance, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analysis are also undertaken to evaluate and compare the lithium storage capability of SrLi2Ti6O14 before and after coating. According to the results, SrLi2Ti6O14@C/Ag presents enhanced electrochemical capability compared with bare material. It can be found that bare SrLi2Ti6O14 only delivers the reversible capacity of 140.32mAhg−1 with capacity retention of 90.7% at 100mAg−1 after 200 cycles. In contrast, SrLi2Ti6O14@C/Ag presents the reversible capacity of 151.20mAhg−1 with only 6.7% capacity loss after 200 cycles. The improvement is owing to the increase of electronic conductivity and the decrease in the redox polarization after coating. In order to further investigate the structural stability of SrLi2Ti6O14@C/Ag, in-situ XRD was performed as well. All the results prove that the C/Ag co-coating has positive effect on the electrochemical performance of SrLi2Ti6O14.

Can microwave assisted in situ reduction of supported Pt nanoparticles challenge the chemical method in controlling the dispersion profile-catalytic performance relationship?

In this comparative study of dispersion profile-catalytic performance relationships, Pt (of 0.3, 0.6 and 0.9 wt%) was supported on mesoporous silica surface via microwave assisted solution method or rotary chemical evaporation method in the in situ reduction step.

Doping dependent properties of Cr-doped ZnO nanostructures prepared by microwave irradiation.

In this work, undoped and Cr-doped single-crystalline ZnO nanorods were prepared by a facile microwave assisted solution method. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results showed that Cr-doped ZnO was comprised of single phase nature with hexagonal wurtzite structure up to 5% Cr doping, however, secondary phase ZnCr2O4 appeared upon further increasing the Cr dopant concentration. Field emission scanning electron microscopy (FESEM) and TEM micrographs suggested that the undoped nanorods with an average length of -~2 μm and a diameter in the range of 150-200 nm, respectively were observed. Interestingly, the size of nanorods decreased with the increase of Cr concentration in ZnO. Optical studies depicted that the energy bandgap was decreased with the increase of Cr concentration. Raman scattering spectra of Cr-doped ZnO revealed the lower frequency shift of E2(high) phonon mode with the increase in concentration of Cr dopant, suggested the successful doping of Cr into Zn site in ZnO. Magnetic studies showed that Cr-doped ZnO exhibited room temperature ferromagnetism (RTFM) and the value of magnetization was continuously decreased with the increase in Cr doping.

Enhanced arsenate removal performance of nanostructured goethite with high content of surface hydroxyl groups

Goethite (α-FeOOH) with high content of surface hydroxyl groups was synthesized by using a simple sodium dodecyl sulfate (SDS) assisted solution method. The presence of SDS can increase the surface area and the contents of surface hydroxyl groups. The adsorption properties towards arsenate (As(V)) ions were investigated, including adsorption kinetics, adsorption isotherm, influences of pH and coexisting anions, and regeneration of the adsorbent. The maximal adsorption capacity was 60.6mgg−1 at pH 7.0, which is about three times larger than the ones synthesized in pure water, and also is favorable compared to those reported in the literature using other adsorbents. The coexisting of phosphate and carbonate inhibited the As(V) removal especially at high concentrations. The as-prepared α-FeOOH could be readily regenerated using NaOH solution and be repeatedly used in the field of water purification. In addition, the removal mechanism was revealed by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and the zeta potential study. The point of zero charge (pHPZC) of the α-FeOOH is 6.35. At high solution pH, the ion-exchange between the surface hydroxyl groups and As(V) ions dominates in the adsorption of As(V). Around the pHPZC, the hydrogen bonding also contributes to the As(V) removal. When the solution pH is lower than pHPZC, the electrostatic attraction plays key roles in As(V) removal.

Defect induced room temperature ferromagnetism in well-aligned ZnO nanorods grown on Si (100) substrate

In this work, we report the fabrication of high quality single-crystalline ZnO nanorod arrays which were grown on the silicon (Si) substrate using a microwave assisted solution method. The as grown nanorods were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), photo-luminescence (PL) and magnetization measurements. The XRD results indicated that the ZnO nanorods are well oriented with the c-axis perpendicular to the substrate and have single phase nature with the wurtzite structure. FE-SEM results showed that the length and diameter of the well aligned rods is about ~ 1 μm and ~ 100 nm respectively, having aspect ratio of 20–30. Room-temperature PL spectrum of the as-grown ZnO nanorods reveals a near-band-edge (NBE) emission peak and defect induced green light emission. The green light emission band at ~ 583 nm might be attributed to surface oxygen vacancies or defects. Magnetization measurements show that the ZnO nanorods exhibit room temperature ferromagnetism which may result due to the presence of defects in the ZnO nanorods.