X-ray diffraction (XRD) profile analysis and optical properties of Klockmannite copper selenide nanoparticles synthesized via microwave assisted technique

In this study, copper selenide (CuSe) nanoparticles (NPs) were prepared using the microwave irradiation technique. The effect of the irradiation time on the structural properties of CuSe NPs was investigated. The XRD results confirms the formation of the hexagonal (Klockmannite) structure of CuSe NPs. Different X-ray diffraction profile analysis techniques comprising strain-size plot (SSP), Scherer’s method (S-M), Monshi-Scherer’s method (MSM), Halder-Wagner (H–W) technique, and Williamson-Hall technique (WHM) were employed to examine the effect of irradiation time on the particle size as well as intrinsic strain of CuSe NPs using XRD peak broadening analysis. Uniform deformation model, uniform stress deformation model, as well as uniform energy density deformation model of Williamson-Hall technique were used to calculate the average crystallites size of CuSe NPs. Essential physical variables involving stress and energy density were also computed. Also, field emission scanning electron microscope (FESEM) in addition to atomic force microscopy (AFM) were further used to determine the mean particle size of CuSe NPs depending on varying irradiation time. The obtained results were found to be in agreement and comparable with the results of XRD profile analysis methods. Raman spectroscopy revealed three vibrational bands which are ascribed to the CuSe vibrational modes. Furthermore, the optical characteristics of the synthesized CuSe NPs were also investigated. The result obtained revealed a decrease in the optical bandgap from 2.43 to 2.71 eV with increase in irradiation time. Photoluminescence study revealed two peaks at 530, and 610 nm respectively. Therefore, it can de deduced that inclusion of intrinsic strain play an important role on the estimation of CuSe NPs size and microstrain of CuSe NPs synthezed vi microwave assisted synthesis technique.     

Insight of electrical behavior in ferroelectric‐semiconductor polymer nanocomposite films of PVDF/ZnSe and PVDF/Cu:ZnSe

Nanocomposite thin films (NCTF) of low‐dimensional ZnSe and copper doped ZnSe integrated poly(vinylidene fluoride) (PVDF) polymer were developed via simple solution casting method. Herein, ZnSe and Cu:ZnSe nanoparticles were synthesized through the chemical reduction technique. The obtained low‐dimensional nanoparticles and NCTFs were characterized by XRD, SEM/EDS, TEM, and FTIR analysis. Room temperature dielectric and ferroelectric characteristics of PVDF/ZnSe flexible NCTF exhibited superior dielectric and ferroelectric behavior with a high coercive field of 15.6 V. Whereas, the dielectric and ferroelectric characteristics were greatly diminished in the PVDF/Cu:ZnSe flexible NCTF was due to the conducting behavior of copper ions at the interface of the polymer network. These results indicated that the PVDF/ZnSe flexible NCTF will be a potential candidate for advanced electrical applications and device fabrication. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44983.     

硒化锌晶体的水热控制生长

以水合肼为还原剂,分别用ZnCl2和Se粉作锌源和硒源,在140℃水热处理24h合成了ZnSe纳米粉末。然后以其为原料,在270℃,NaOH浓度为4mol/L,填充度为65%时,通过改变反应时间,生长了不同形貌的硒化锌晶体。用X射线衍射(XRD)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)等技术手段,分别对产物进行了表征,并从ZnSe晶体的结构上对其形貌的形成进行了初步分析。     

Synthesis and Characterization of Cadmium Selenide (CdSe) Nanoparticles Using Trigonal Selenium (t-Se) Nanorods as Selenium Source

Cadmium selenide (CdSe) nanoparticles were synthesized through colloidal method in aqueous medium using the reaction intermediates selenium nanorods as selenium source. Trigonal selenium nanorods (t-Se) were synthesized in water by the reduction method in the presence of sodium borohydride at 60?°C using sodium selenite (Na₂SeO₃) as selenium source. These selenium nanorods were further utilized to synthesis cadmium selenide nanoparticles at 100?°C in water. The synthesized nanorods and nanoparticles were characterized using XRD, SEM, TEM and XPS analysis. X-ray diffraction (XRD) analysis shown that the nanorods possess trigonal phase while the nanoparticles possess a cubic zinc blende structure. Scanning electron microscope (SEM) analysis of the prepared hexagonal shaped nanorods reveals the diameter of the nanorods are about 150 nm. Transmission electron microscopy (TEM) analysis shows the size of the synthesized CdSe nanoparticles are about 4–8 nm. X-ray photoelectron spectroscopy (XPS) analysis illustrates the presence of respective elements Cd, Se with its corresponding oxidation states. The activity of nano selenium rods in aqueous solution during the conversion of cadmium selenide nanoparticles was discussed.     

Pectin-graft-poly(2-acrylamido-2-methyl-1-propane sulfonic acid) silver nanocomposite hydrogel beads: evaluation as matrix material for sustained release formulations of ketoprofen and antibacterial assay

Pectin-graft-poly(2-acrylamido-2-methyl-1-propane sulfonic acid) (Pec-g-PAMPS) gel was made in the form of beads by subjecting the solution containing pectin (Pec), 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) and ammonium peroxodisulphate to microwave irradiation followed by ionic crosslinking in CaCl₂ solution. Gel beads containing silver nanoparticles were also prepared by the same method but with the addition of silver nitrate and trisodium citrate solution prior to microwave irradiation. The synthesized Pec-g-PAMPS and its silver nanocomposite (Pec-g-PAMPS-Ag) gel beads were characterized using FTIR, TGA, XRD, SEM, EDS and TEM techniques. The effect of incorporation of Ag NPs on the biological activity of Pec-g-PAMPS was studied by zone inhibition method considering two bacterial strains namely E. coli and B. subtilis. The nanocomposite gel exhibited higher antibacterial activity compared to the parent gel, which was comparable with the standard drug, Streptomycin. The in vitro drug release profiles of the parent gel and its composite were analyzed using Ketoprofen (KF) to study the effect of incorporation of Ag NPs on the drug release behavior of the Pec-g-PAMPS. The presence of silver nanoparticles enhanced both swelling of the gel beads and the extent of drug release significantly.     

Effect of calcination temperature on structural,vibrational, optical,and rheological properties of zirconia nanoparticles

ZrO₂ nanoparticles (NPs) were prepared by a simple, versatile, and an efficient methodology based on microwave. The synthesized NPs were calcined at temperatures ranging from 100 °C to 600 °C. The samples were characterized by X-ray powder diffraction (XRD), transmission electron microscope (TEM), FT-IR spectroscopy, Far-IR spectroscopy, Raman spectroscopy, and UV-vis absorption spectroscopy. The results clearly showed the presence of purely monoclinic phase of zirconia when the calcination temperature exceeds 400 °C. The experimental results showed that the viscosity of zirconia NPs in ethylene glycol (EG) increases with increasing the particle volume fraction and decreases with increasing temperature.     

Radiation synthesis and characterization of polyvinyl alcohol/chitosan/silver nanocomposite membranes: antimicrobial and blood compatibility studies

Polyvinyl alcohol/chitosan/silver (PVA/CS/Ag) nanocomposite membranes were synthesized by γ-radiation with promising antimicrobial and biomedical applications. The nanocomposite membranes were prepared by mixing PVA and CS solutions with different copolymer compositions in the presence of silver nitrate (AgNO₃) and glutaraldehyde as cross-linker, followed by in situ reduction with γ-radiation at different doses. The nanocomposite membranes were characterized by ultraviolet spectroscopy (UV), Fourier transform infrared, X-ray diffraction (XRD) and transmission electron microscopy (TEM). UV studies showed a strong peak around λ _max at 430 nm due to surface plasmon resonance of silver nanoparticles formed during irradiation. As the irradiation dose increased from 25 to 75 kGy, the plasmon band is shifted from 430 to 418 nm with high intensity, indicating the formation of smaller particles. TEM investigation showed uniform distribution of silver nanoparticles (AgNPs) in the membranes with mean diameter of 32–19 nm. XRD results confirmed that the mean diameter of AgNPs estimated from the Debye–Scherrer formula was in the range of 27.5–12.8 nm which confirms the TEM results. The PVA/CS/Ag nanocomposite membranes exhibited good antibacterial activity and were found to cause significant reduction in microbial growth. The nanocomposite membranes showed non-thrombogenicity effect and slightly haemolytic potential, suggesting their promising use in biomedical applications.     

EDTA-assisted template-free synthesis and improved photocatalytic activity of homogeneous ZnSe hollow microspheres

Homogeneous ZnSe hollow microspheres were synthesized on a large scale through an EDTA-assisted mixed solvothermal strategy without any surfactants and templates. The as-synthesized ZnSe microspheres were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV–vis absorption spectroscopy. The results of photodegradation of methylene blue (MB) indicate that the hollow microspheres exhibit a visible-light-responsive photocatalytic behavior. As compared with the bulk ZnSe, the photocatalytic efficiency for the hollow microspheres was enhanced remarkably, which might be related with the hollow aggregates of ZnSe nanocrystallites.     

Synthesis and characterization of monodisperse NiFe2O4 nanoparticles

Narrow size distribution nickel ferrite nanoparticles with average particle size of around 6 nm has been synthesized via rapid thermo-decomposition method in the presence of oleylamine in solution which acted as neutralizing, stabilizing and reducing agent OAm coated NiFe₂O₄ NPs. X-ray powder diffraction (XRD), Fourier Transform Infrared Spectra (FT-IR), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), Vibrating Simple Magnetometer (VSM) and also Mössbauer Spectroscopy were used for structural, morphological, spectroscopic and magnetic characterization of the product. The XRD analysis revealed the formation of single phase nickel ferrite with Fd-3m space group. Both FT-IR and TGA analyses confirmed the formation of desired nanocomposite. FT-IR analysis also showed characteristic IR absorption bands of the spinel nickel ferrite phase and oleylamine. TEM and SEM analysis showed that product have almost spherical structural morphology. TEM images showed that NiFe₂O₄ nanoparticles have narrow size distribution and Energy Dispersive X-ray (EDX) analysis confirmed the presence of metal ions in the required stoichiometric ratio. Superparamagnetic property of the product was confirmed by VSM. From ⁵⁷Fe Mössbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting and hyperfine magnetic field values have been determined. The Mössbauer spectra for OAm coated NiFe₂O₄ NPs. is consisting of one paramagnetic central doublets and one magnetic Zeeman sextet. Finally, the synthetic procedure can be extended to the preparation of high quality metal or alloy nanoparticles.     

Synthesis of Fe:ZnSe nanopowders via the co-precipitation method for processing transparent ceramics

Fe:ZnSe nanopowders were synthesized via the co-precipitation method for fabricating transparent ceramics. Fe_xZn_1−xSe (0.00 ≤ x ≤ 0.06) powders that were calcined at 400°C yielded a single-phased cubic ZnSe, but when the calcination temperature was raised to 500-600°C, ZnO phase was created. Introduction of pressure could avoid appearance of ZnO. XRD Scherrer analysis revealed a monotonic increase in lattice parameter with increasing Fe²⁺ content. The average powder particle size increased with calcination temperature from several nanometers at 80°C to hundreds of nanometers at 600°C. Attempts to pressurelessly sinter ZnSe powders resulted in the partial decomposition of ZnSe, thus spark plasma sintering was employed to sinter Fe_0.01Zn_0.99Se transparent ceramics with pure ZnSe phase composition, which could be well sintered at 950°C for 30 minutes under an applied pressure of 60 MPa. SEM observations of the polished and thermally etched microstructure of the ceramic revealed a dense microstructure with average grain size of approximately 35 μm, and a few micropores were observed at the grain boundaries. The transparent ceramic exhibited good transmittance in the mid-far infrared range, with the highest transmittance 57% at 12 μm. This paper confirmed the scheme of synthesis of Fe:ZnSe nanopowders by liquid-phase co-precipitation method for sintering transparent ceramics.     

Microwave Synthesis and Characterization of Spinel-type Zinc Aluminate Nanoparticles

In the present work, ZnAl₂O₄ nanoparticles have been synthesized with the aid of Zn(OAc)₂·2H₂O and Al(NO₃)₃·9H₂O as starting reagents in the presence of microwave irradiation. Besides, the effect of preparation parameters such as microwave power and irradiation time on the morphology and particle size of products was studied by SEM images. The as-prepared ZnAl₂O₄ nanoparticles were characterized extensively by techniques like XRD, TEM, SEM, FT-IR, PL, and EDS. Photoluminescence studies of the ZnAl₂O₄ nanoparticles displayed quantum confinement behavior with band gap of 3.2 eV. The XRD studies showed that pure orthorhombic ZnAl₂O₄ nanoparticles have been produced after calcination.     

Green synthesis of Ni@Fe3O4 and CuO nanoparticles using Euphorbia maculata extract as photocatalysts for the degradation of organic pollutants under UV-irradiation

This paper presents a fast, biogenic and green method for the synthesis of highly stable and small sized metal nanoparticles (MNPs). This technique has some benefits compared to the conventional physical and chemical methods. It is simple, rapid, cheap and environmentally friendly. In addition, it does not require any costly or hazardous chemicals. The extracts of Euphorbia maculata aerial parts were used in a green synthesis method in order to prepare magnetic Ni@Fe₃O₄ and CuO NPs. Fourier transforms infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), ultraviolet–visible (UV–Vis), energy dispersive X-ray spectrometry (EDS), Brunauer-Emmett-Teller (BET) and thermo gravimetric-differential thermal analysis (TGA) analytical techniques were used for analyzing the green synthesized compounds. The photocatalytic activity of the synthesized NPs was tested in the degradation of different organic dye pollutants such as congo red (CR), methylene blue (MB) and Rhodamine B (RhB) under UV irradiation. The effects of different parameters such as nanoparticle dosage, contact time, pH, and initial dye concentrations on the capacity of the photocatalyst adsorption were also studied. The comparison of the photocatalytic activity of the biosynthesized nanoparticles reveals that the catalytic activity of CuO NPs is higher than that of Ni@Fe₃O₄ NPs. Furthermore, good photocatalytic stability of the NPs in the degradation of MB under UV light irradiation was observed after the recycling. The photocatalyst efficiency did not considerably change after four cycles, which indicated excellent photocatalytic stability.     

ZnSe纳米棒的水热法合成及发光性能研究

以氢氧化钠、单质硒粉与4种不同锌盐为起始原料、EDTA为软模板剂,在190℃水热条件下合成了ZnSe半导体材料。采用X-射线粉末衍射(XRD)、扫描电镜(SEM)、X-射线光电子能谱(XPS)、荧光光谱(FS)、紫外可见吸收光谱(UV-Vis)等测试手段对所得样品的物相结构、化学组成、形貌和性能进行了测试。结果表明,所得ZnSe为立方闪锌矿型结构且纯度较高;锌源对产物的形貌具有一定的影响;合成的粉体在紫外区有强的吸收峰,具有良好的光学性能。     

XPS and UV–vis studies of Ga-doped zinc oxide nanoparticles synthesized by gelatin based sol-gel approach

Undoped and gallium-doped ZnO nanoparticles, (ZnO NPs) (Zn_1−xGa_xO, x=0.0, 0.03, 0.06, 0.09, 0.12, 0.15), were synthesized by a gelatin-based, sol–gel method. Structural and morphological studies of the resulting products were carried out via X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The XRD results revealed that the sample products were crystalline with a hexagonal wurtzite phase. Furthermore, the TEM images indicated ZnO NPs having approximately spherical shapes, with their particle size distributed over the nanometer range. The XRD and TEM results also showed a decrease in crystallite and particle sizes of NPs from x=0.0 to 0.15. The size-strain plot (SSP) method was employed to study the individual contributions of crystallite sizes and lattice strain to the peak broadening of the undoped and doped ZnO NPs. The effect of doping on the optical band-gap and crystalline quality was also investigated, using ultraviolet-visible (UV–vis), X-ray photoluminescence (XPS), and spectroscopies of the pure and doped ZnO NPs. It was observed that the band-gap and O-vacancies of the doped ZnO NPs were red-shifted in comparison with those of the undoped ZnO NPs in UV–vis and XPS results.     

Microstructural and Mössbauer properties of low temperature synthesized Ni-Cd-Al ferrite nanoparticles

We report the influence of Al³⁺ doping on the microstructural and Mössbauer properties of ferrite nanoparticles of basic composition Ni_0.2Cd_0.3Fe_{2.5 - x}Al_xO₄ (0.0 ≤ x ≤ 0.5) prepared through simple sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray, transmission electron microscopy (TEM), Fourier transformation infrared (FTIR), and Mössbauer spectroscopy techniques were used to investigate the structural, chemical, and Mössbauer properties of the grown nanoparticles. XRD results confirm that all the samples are single-phase cubic spinel in structure excluding the presence of any secondary phase corresponding to any structure. SEM micrographs show the synthesized nanoparticles are agglomerated but spherical in shape. The average crystallite size of the grown nanoparticles was calculated through Scherrer formula and confirmed by TEM and was found between 2 and 8 nm (± 1). FTIR results show the presence of two vibrational bands corresponding to tetrahedral and octahedral sites. Mössbauer spectroscopy shows that all the samples exhibit superparamagnetism, and the quadrupole interaction increases with the substitution of Al³⁺ ions.     

Facile preparation of highly dispersed Pt nanoparticles supported on heteroatom-containing porous carbon nanospheres and their catalytic properties for the reduction of 4-nitrophenol

Heteroatom-containing porous carbon nanospheres with a high surface area were firstly fabricated by pyrolysis of poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanospheres which were fabricated by a facile polycondensation between hexachlorocyclotriphosphazene and 4,4′-sulfonydiphenol. Then the porous carbon nanosphere-supported Pt nanoparticles (Pt NPs@C-PZS) were synthesized by a simple microwave reduction method, during which Pt NPs were highly dispersed on the surface of carbon supports. The surface morphologies and chemical composition of the as-obtained C-PZS and Pt NPs@C-PZS nanocomposites were characterized by SEM, TEM, XRD, XPS, and Raman spectroscopy. Characterization results showed that the Pt NPs with an average diameter of 2 nm was well anchored onto the surface of C-PZS nanospheres. In addition, the as-prepared Pt NPs@C-PZS nanocomposites exhibited an excellent catalytic capability towards the reduction of 4-nitrophenol to 4-aminophenol by excessive sodium borohydride (NaBH₄) at room temperature.     

Optical and electrical properties of p-type Ag-doped ZnO nanostructures

Zn_1−xAg_xO nanoparticles (NPs) (x=0, 0.02, 0.04, and 0.06) were synthesized by a sol–gel method. The synthesized undoped ZnO and Zn_1−xAg_xO-NPs were characterized by X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and UV–visible spectroscopy. The XRD patterns indicated that undoped and Ag-doped ZnO crystallize in a hexagonal wurtzite structure. The TEM images showed ZnO NPs with nearly spherical shapes, with particle size distributed over the nanometer range. Evidence of dopant incorporation is demonstrated in the XPS measurements of the Ag-doped ZnO NPs. The Raman measurements indicated that the undoped and Ag-doped ZnO-NPs had a high crystalline quality. From the result of UV–vis, the band-gap values of prepared undoped and Ag-doped ZnO were found to decrease with an increase in Ag concentration. The obtained undoped and Ag-doped ZnO nanoparticles were used as a source material to grow undoped and Ag-doped ZnO nanowires on n-type Si substrates, using a thermal evaporation set-up. Two probe method results indicated that the Ag-doped ZnO nanowires exhibit p-type properties.     

The effect of group-I elements on the structural and optical properties of ZnO nanoparticles

Undoped and group-I elements doped ZnO nanoparticles (NPs) (Zn_1?yX_2yO, X=Li, Na, K, and y=0.05) were synthesized by a sol–gel method. Structural and morphological studies of the resulting products were carried out by X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The XRD results revealed that the sample products were crystalline with a hexagonal wurtzite phase. The TEM images showed ZnO NPs with nearly spherical shapes with particle size distributed over the nanometer range. In addition, the XRD and TEM results showed a decrease in crystallite and particle sizes of NPs from Li-doped to K-doped ZnO NPs. Crystalline development in the ZnO NPs was investigated by X-ray peak broadening. The size-strain plot (SSP) method was used to study the individual contributions of crystallite sizes and lattice strain on the peak broadening of the undoped and doped ZnO NPs. The effect of doping on the optical band-gap and crystalline quality was also investigated by using photoluminescence (PL) and Raman spectrometers. The Raman spectra of the all ZnO NPs showed a strong E₂(high) peak. The PL spectra exhibited a strong peak in the ultraviolet (UV) region of the electromagnetic spectrum for the all ZnO NPs. The UV peak of the doped ZnO NPs was red-shifted with respect to that of the undoped ZnO NPs.     

Sulfur Nanoparticles Synthesis and Characterization from H2S Gas, Using Novel Biodegradable Iron Chelates in W/O Microemulsion

Sulfur nanoparticles were synthesized from hazardous H₂S gas using novel biodegradable iron chelates in w/o microemulsion system. Fe³⁺–malic acid chelate (0.05 M aqueous solution) was studied in w/o microemulsion containing cyclohexane, Triton X-100 and n-hexanol as oil phase, surfactant, co-surfactant, respectively, for catalytic oxidation of H₂S gas at ambient conditions of temperature, pressure, and neutral pH. The structural features of sulfur nanoparticles have been characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), diffused reflectance infra-red Fourier transform technique, and BET surface area measurements. XRD analysis indicates the presence of α-sulfur. TEM analysis shows that the morphology of sulfur nanoparticles synthesized in w/o microemulsion system is nearly uniform in size (average particle size 10 nm) and narrow particle size distribution (in range of 5–15 nm) as compared to that in aqueous surfactant systems. The EDS analysis indicated high purity of sulfur (>99%). Moreover, sulfur nanoparticles synthesized in w/o microemulsion system exhibit higher antimicrobial activity (against bacteria, yeast, and fungi) than that of colloidal sulfur.     

A new sensor based on amino-functionalized zirconium metal-organic framework for detection of Cu2 + in aqueous solution

Amino(-NH₂) functionalized zirconium metal-organic framework UiO-66 were synthesized in household microwave oven. The structural properties and morphology of the obtained UiO-66-NH₂ nanoparticles were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS). UiO-66-NH₂ sensor show high selectivity and sensitivity toward Cu^2 + over other tested metal ions. In addition, the possible sensing mechanism is also discussed.