Microwave-assisted synthesis of CePO_4 nanorod phosphor with violet emission

Monochnic and hexagonal CePO4 nanoparticles and nanorods were successfully synthesized from Ce（NO3）36H2O and Na3PO4 121-120 solu- tions at pH 1-5 by a 180 W microwave radiation for 60 min. The products were characterized by X-ray diffraction （XRD）, Fourier transform infrared （FFIR） spectroscopy, and scanning electron microscopy （SEM）. XRD patterns revealed that the products are hexagonal CePO4 structures at pH 2-5, and monoclinic CePO4 structtLres at pH 1. SEM characterization shows that these products were nanoparticles, short nanorods, and long nanorods, controlled by the pH of the precursor solutions. Optical properties of the nanorods were also investigated by ultraviolet-visible （UV-vis） and photoluminescence （PL） spectroscopy.

Facile sonochemical synthesis and photocatalysis of Ag nanoparticle/ZnWO4-nanorod nanocomposites

A facile sonochemical method was developed to synthesize metallic Ag spherical nanoparticles on the surface of ZnWO4 nanorods by forming heterostructure Ag/ZnWO4 nanocomposites.The Ag/ZnWO4 nanocomposites were characterized by X-ray powder diffraction (XRD),Fourier transform infrared spectroscopy (FTIR),field emission scanning electron microscopy (FESEM),transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS).The experimental results showed that fcc metallic Ag nanoparticles were supported on surface of monoclinic sanmartinite ZnWO4 nanorods.The Ag 3d3/2 and Ag 3d5/2 peaks have well-separated binding energies of 6.00 eV,certifying the existence of metallic Ag.The Ag/ZnWO4 nanocomposites were evaluated for photodegradation of methylene blue (MB) induced by ultraviolet-visible (UV-Vis) radiation.In this research,heterostructure 10 wt% Ag nanoparticle/ZnWO4-nanorod composites have the highest photocatalytic activity of 99% degradation of MB within 60 min.The increase in photocatalytic activity was the result of photoinduced electrons in conduction band of ZnWO4 that effectively diffused to metallic Ag spherical nanoparticles and the inhibition of electron-hole recombination process.

Sonochemical synthesis and characterization of uniform lanthanide orthophosphate(LnPO_4, Ln=La and Ce) nanorods

Uniform lanthanide orthophosphate （LnPO4, Ln = La and Ce） nanorods were successfully synthesized by a simple ultrasonic irradiation method using lanthanide nitrate salt （Ln（NO3）3-6H2O, Ln = La and Ce） and sodium phosphate （Na3PO4） in aqueous solutions with the pH of 1-3. The products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM）, Fourier transform infrared spectrometer （FT-IR）, and UV-visible （UV-Vis） spectroscopy. In this research, the products are nanorods of monoclinic LaPO4 and hexagonal CePOa structures and the vibration modes of PO4^3-, including the strong peaks at 227 nm for LaPO4, and at 225 and 278 nm for CePO4.

Photoluminescence and photonic absorbance of Ce_2(MoO_4)_3 nanocrystal synthesized by microwave-hydrothermal/solvothermal method

In this research, cerium （III） nitrate hexahydrate （Ce（NO3）3·6H2O） and ammonium molybdate tetrahydrate （（NH4）6Mo7O24·4H2O） with Ce3＋-to-Mo6＋ molar ratio of 2：3 were dissolved in 40 ml different solvents of deionized （DI） water, polyethylene glycol （PEG） and ethylene glycol （EG） to form different solutions which were followed by adjusting pH from the traditional values to 7.0 and 10.0 with 1 mol.L-1 sodium hydroxide （NaOH）. Subsequently, the solutions were processed by 270-W microwave-hydrother- mal/solvothermal method. Phase, morphology, vibrational modes and photonic properties were fully characterized by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FTIR）, Raman spectrophotometry, ultraviolet-visible （UV-Vis） absorption and photoluminescence （PL） spectroscopy. The as-synthe-sized products were pure cerium molybdenum oxide （Ce2（MoO4）3） of nanoparticles clustered together as nano- plates in DI water and PEG solvents, and of spindle-like nanoparticles in EG solvent, including the presence of Ce-O-H mode and MoO4 units. The results show that direct energy gaps of the first two have the same value of 2.30 eV, and that of the last is 2.80 eV, including their blue emission at the same wavelength of 488 nm.

Photocatalysis of Cd-doped ZnO synthesized with precipitation method

ZnO particles doped with 0 mol%-5 mol% Cd dopant were successfully synthesized by a precipitation method.The as-synthesized products were characterized by thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),X-ray diffraction(XRD),photoluminescence(PL) spectroscopy,Raman spectroscopy,scanning electron microscopy(SEM) coupled with an energydispersive X-ray(EDX) spectroscopy and transmission electron microscopy(TEM).The precursors showed weight loss at 35-700℃ caused by phase transformation and evaporation processes.The as-synthesized products were specified as hexagonal wurtzite ZnO.The crystallite size of ZnO samples doped with 0 mol%-5 mol% Cd gradually increased with the increase in Cd content.The photocatalytic activities of 0 mol%-5 mol% Cd-doped ZnO samples were evaluated through photodecolorization of methylene blue(MB) under ultraviolet(UV) radiation.In this research,ZnO doped with 3 mol% Cd shows the best photocatalytic activity in degrading of MB molecules as much as 89% within 240 min.

Synthesis and characterization of Gd-doped PbMoO_(4) nanoparticles used for UV-light-driven photocatalysis

Gd-doped PbMoO_(4) nanoparticles were prepared by a refluxing method at 80℃ for 2 h.Effect of molar content of Gd dopant on phase,morphology and optical properties was studied.The as-prepared Gddoped PbMoO_(4) samples can be indexed to pure tetragonal PbMoO_(4) phase.The particles size of PbMoO_(4) is decreased with increasing in the molar content of Gd dopant from 15.20±3.04 nm for pure PbMoO_(4) to 8.72±1.53 nm for 5 mol% Gd-doped PbMoO_(4).The absorption of 5 mol% Gd-doped PbMoO_(4) nanoparticles shows red-shift caused by lattice distortion of PbMoO_(4).The photocatalytic performance of 5 mol% Gddoped PbMoO_(4) nanoparticles shows the highest degradation of rhodamine B(RhB) of 97.92% under UV radiation and 67.65% under visible radiation because Gd^(3+) dopant as an electron acceptor plays the role in enhancing the separation of electron-hole pair.

Photocatalytic activity of La-doped ZnO nanostructure materials synthesized by sonochemical method

ZnO nanostructure materials doped with different La contents were synthesized by sonochemical method. The products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）,transmission electron microscopy（TEM）, Raman spectroscopy, and Fourier transform infrared spectroscopy（FTIR）. In this research, XRD patterns of pure ZnO and La-doped ZnO are specified as hexagonal wurtzite ZnO structure with no detection of La2O3 phase. SEM and TEM characterization revealed the flower shape of pure ZnO built-up from petals of hexagonal prisms with hexagonal pyramid tips. Upon doping with La, the flower-shaped ZnO is broken into individual 1D prism-like nanorods. Photocatalytic activities of the as-synthesized products were determined by measuring the degradation of methylene blue（MB） under ultraviolet–visible（UV） light irradiation.Among them, the 2.0 mol% La-doped ZnO shows better photocatalytic properties than any other products.

Hydrothermal synthesis and characterization of Dy-doped CeVO_(4) nanorods used for photodegradation of methylene blue and rhodamine B

Pure CeVO_(4) and Dy-doped CeVO_(4) nanorods containing different weight contents of Dy dopant were synthesized by hydrothermal method.Effect of Dy dopant on photodegradation of methylene blue(MB)and rhodamine B(RhB) was evaluated under UV light irradiation within 80 min.Pure CeVO_(4) and Dydoped CeVO_(4) nanorods were characterized by X-ray diffraction(XRD),Raman spectroscopy,transmission electron microscopy(TEM) and UV-visible spectroscopy.In this research,CeVO_(4) nanorods are tetragonal phase with the detection of main peak shift after being doped with Dy.The length of nanorods is deceased from 50 to 200 nm for pure CeVO_(4) to 50-100 nm for 3% Dy-doped CeVO_(4).Photodegradation of MB and RhB by CeVO_(4) nanorods under UV light irradiation is improved by Dy-dopant that plays the role in accepting electrons and reducing electron-hole recombination.MB and RhB solutions degraded by 3% Dy-doped CeVO_(4) nanorods was 94% and 93% within 80 min,respectively.

Sonochemical synthesis,characterization,and magnetic properties of Mn-doped ZnO nanostructures

Mn-doped ZnO samples,Zn_(1-x)Mn_(x)O(x=0,0.01,0.03 and 0.05;mole fraction),were successfully synthesized by sonochemical method.The undoped and Mn-doped Zn O samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and Raman spectroscopy.XRD patterns of all products are identified to hexagonal wurtzite Zn O structure and their three main peaks shift toward lower diffraction angles due to the incorporation of Mn^(2+)into Zn O crystal lattice.The morphologies of Zn_(1-x)Mn_(x)O(x=0,0.01,0.03 and 0.05)were examined by SEM and TEM.The undoped Zn O sample shows large-scale uniform microflowers which are broken into nanorods and nanoparticles by Mn dopant.Their magnetic properties were investigated by a vibrating sample magnetometer at room temperature.The magnetization-applied field behavior of undoped Zn O defines its weak ferromagnetic behavior.The 3 mol%Mn-doped Zn O shows the highest saturation magnetization of 51.73910^(-3)m A·m^(2)·g^(-1),and the 5 mol%Mn-doped Zn O has suppressed ferromagnetic property due to the formation of Mn clusters inside.