Oranuch Yayapao

Synthesis and Characterization of Europium-Doped Zinc Oxide Photocatalyst

Single crystalline flower-like ZnO and Eu-doped ZnO structures were successfully synthesized via a sonochemical method. Structures, morphologies, and photocatalytic activities of the as-synthesized samples were determined using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and ultraviolet-visible absorption spectroscopy. The photocatalytic activities of the as-synthesized samples were evaluated by the degradation of methylene blue in aqueous solutions under UV light. The photocatalytic results indicate that the as-synthesized Eu-doped ZnO shows good photocatalytic activity and could be considered as a promising photocatalyst for dye waste water treatment.

Photocatalytic degradation of organic dyes by UV light, catalyzed by nanostructured Cd-doped ZnO synthesized by a sonochemical method

ZnO and Cd-doped ZnO photocatalysts were successfully synthesized by use of a sonochemical method. The as-synthesized ZnO and Cd-doped ZnO photocatalysts were characterized by X-ray diffraction, Raman spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller analysis, inductively couple plasma-optical emission spectrometry, and X-ray photoelectron spectroscopy. The as-synthesized ZnO and Cd-doped ZnO photocatalysts were pure wurtzite hexagonal ZnO phase. The Raman-active E2H mode of ZnO, located at 437xa0cm−1, corresponded to the characteristic band of the hexagonal wurtzite phase. The photocatalytic activity of the pure ZnO and Cd-doped ZnO photocatalysts was investigated by studying the degradation of methylene blue (MB) and methyl orange (MO), in solution, under UV irradiation. Compared with pure ZnO, 3xa0% Cd-doped ZnO reduced the amounts of MB and MO by 65xa0% and 45xa0%, respectively, within 300xa0min. The results indicated that Cd dopant substantially increased the photocatalytic activity of ZnO.

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 2.0xa0mol% La-doped ZnO shows better photocatalytic properties than any other products.

Photocatalytic activity of ZNO with different morphologies synthesized by a sonochemical method

Different morphologies of ZnO structures were successfully synthesized in precursor solutions with the pH of 8, 9, 10, 11, and 12 by a sonochemical method at room temperature. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) and Raman spectroscopy. The photocatalytic activities of ZnO samples with different morphologies were evaluated via the degradation of methylene blue (C16H18ClN3S). In this research, the flower-like ZnO sample of densely assembled nanoplates exhibited the highest photodegradation of 64% under UV light irradiation within 300 min.

Ultrasonic-assisted synthesis, characterization, and optical properties of Sb doped ZnO and their photocatalytic activities

Sb doped ZnO nanostructures were synthesized by an ultrasonic-assistedmethod. Effect of Sb dopant on the structure, morphology, and composition of as-synthesized Sb doped ZnO nanostructures was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and transmission electron microscopy (TEM). All samples were identified to wurtzite hexagonal ZnO structure. UV-visible spectra of the as-synthesized 3% Sb doped ZnO sample exhibit broad absorption bands at around 343 nm which is blue shift of 373 nm of pure ZnO. The photocatalytic activity was tested by decolorization of methylene blue (MB) solution under UV light. After 300 min irradiation, the degradation efficiencies were 56, 90, and 95% for ZnO, 1% Sb doped ZnO, and 3% Sb doped ZnO, respectively. The 3% Sb doped ZnO shows the highest photocatalytic activity than any other samples.

Hydrothermal synthesis of hexagonal WO3 nanowires with high aspect ratio and their electrochemical properties for lithium-ion batteries

One dimensional WO3 nanowires with high aspect ratio of >200 were synthesized by hydrothermal method. The effects of reaction temperature and time on phase and morphologies were studied and discussed. In this research, a suitable hydrothermal condition is at 200°C for 48 h. XRD, SEM, and TEM results show that the product is hexagonal WO3 phase with diameter of 25 nm and several ten micrometers long with growth in the c direction. The electrochemical properties were tested for rechargeable lithium batteries. The WO3 NWs electrode exhibits a stability trend over the 30 cycle testing. Some long-term activation process is attributed to the WO3 NWs electrode during charge/discharge reaction.

Synthesis, characterization and electrochemical properties of α-MoO3 nanobelts for Li-ion batteries

Orthorhombic molybdenum trioxide (α-MoO3) nanobelts have been successfully synthesized by hydrothermal method at 180°C for 20 h. The prepared α-MoO3 samples were investigated by X-ray diffraction, Fourier transform IR spectroscopy, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy methods. It was found that α-MoO3 nanobelts grow along the c-axis, with ±(100) top or bottom surfaces and ±(010) side surfaces. The prepared α-MoO3 nanobelts were used as cathode materials for Li-ion batteries. They exhibit specific capacity of 1340 and 1250 mA h g–1 at a current density of 100 and 400 mA/g, respectively.