Wyniki wyszukiwania - BazTech

1

Fabrication, characterization and photocatalytic properties of CdS nanoparticles modiﬁed by N-doped TiO2 NTs

Gao D., Wang C., Jian Y., Li W., Dong P.

Materials Science Poland

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2018

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Vol. 36, No. 3

348--353

EN

Highly ordered TiO2 nanotube arrays (TiO2 NTs) were prepared by anodic oxidizing method on a surface of Ti substrate. Fabrication of nitrogen-doped TiO2 nanotube arrays (N-TiO2 NTs) was carried out by immersion in ammonia solution. CdS nanoparticles loaded N-doped TiO2 nanotube arrays (CdS/N-TiO2 NTs) were obtained by successive ionic layer adsorption and reaction (SILAR) technique. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), photoluminescence (PL) emission spectra and ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy (DRS). The results indicate that the TiO2 nanotube diameter and wall thickness are 100 nm to 120 nm and 20 nm to 30 nm, respectively. Moreover, the morphology and structure of the highly ordered TiO2 NTs are not affected by N-doping. Furthermore, CdS nanoparticles are evenly distributed on the surface of TiO2 NTs. Finally, the photocatalytic activity of CdS/N-TiO2 NTs was evaluated by degradation of MO under visible-light irradiation. Compared with TiO2 NTs, N-TiO2 NTs, CdS/N-TiO2 NTs exhibited enhanced photocatalytic properties, and the highest degradation rate of CdS/N-TiO2NTs could reach 97.6 % after 90 min of irradiation.

2

Enhanced Photocatalytic Properties of Ag-Loaded N-Doped Tio2 Nanotube Arrays

Gao D., Lu Z., Wang C., Li W., Dong P.

Autex Research Journal

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2018

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Vol. 18, no. 1

67--72

EN

Highly ordered TiO2 nanotube (TiO2 NT) arrays were prepared by anodic oxidizing method on the surface of the Ti substrate. Nitrogen-doped TiO2 nanotube (N-TiO2 NT) arrays were carried out by ammonia solution immersion, and Ag nanoparticles loaded N-doped TiO2 nanotube (Ag/N-TiO2 NT) arrays were obtained by successive ionic layer adsorption and reaction (SILAR) technique. The samples were characterized by the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL) emission spectra, ultraviolet–visible (UV–vis) diffuse reflectance spectroscopy (DRS). The result indicated that the diameter and wall thickness of the TiO2 NT are 100–120 and 20–30 nm, respectively. Moreover, the morphology and structure of the highly ordered TiO2 NTs were not affected by N-doping. Furthermore, Ag nanoparticles were evenly deposited on the surface of TiO2 NTs in the form of elemental silver. Finally, the photocatalytic activity of Ag/N-TiO2 NTs was evaluated by degradation of methyl orange (MO) under visible-light irradiation. The Ag/N-TiO2 NTs exhibited enhanced photocatalytic properties, which could reach 95% after 90-min irradiation.

3

The effect of different organic fluids on performances of binary slag washing water power plants

Li Z., Liu Y., Dong P., Zhang Y., Xiao S.

Archives of Thermodynamics

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2017

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Vol. 38, no. 3

49--62

EN

In this paper, 3 typical organic fluids were selected as working fluids for a sample slag washing water binary power plants. In this system, the working fluids obtain the thermal energy from slag washing water sources. Thus, it plays a significant role on the cycle performance to select the suitable working fluid. Energy and exergy efficiencies of 3 typical organic fluids were calculated. Dry type fluids (i.e., R227ea) showed higher energy and exergy efficiencies. Conversely, wet fluids (i.e., R143a and R290) indicated lower energy and exergy efficiencies, respectively.

4

Guided modes in slab waveguides with both double-negative and single-negative materials

Dong P., Yang H. W.

Optica Applicata

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2010

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Vol. 40, nr 4

873--882

EN

A new dielectric slab waveguide with double-negative (DNG) film layer and single-negative (SNG) cover layer is proposed. The dispersion relations of an asymmetric left-handed materials (LHM) slab waveguide are investigated by using normalized parameters. An analytical method is then proposed to calculate the dispersion curves. TE-polarized guided modes differ dramatically from TM-polarized guided modes. For TE-polarized oscillating guided modes, fundamental modes exist all the time, but in a narrow range of low frequency values only. First order mode behaves as other higher order modes and exists up to infinite high frequency. Higher order modes have double degeneracy. For TE-polarized surface guided modes, the existence and the type of the mode solutions with respect to different parameters are classified systematically and discussed in detail. TE0 surface mode exists only in one case. The dispersion curve of TE1 surface mode continues with that of oscillating TE0 mode. It seems that the two different kinds of modes compensate each other to form one whole mode. For TM-polarized wave, both oscillating and surface guided modes act as the waveguide with DNG (LHM) film sandwiched in between two normal dielectrics.

5

Separation of two main triterpene glycosides from sea cucumber Pearsonothuria graeffei by high-speed countercurrent chromatography

Dong P., Xue C. H., Du Q. Z.

Acta Chromatographica

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2008

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Vol. 20, no. 2

269-276

EN

Holostane series glycosides have been isolated by a new and effective method. Two main triterpene glycosides from sea cucumber Pearsonothuria graeffei extract were successfully purified by one-step high-speed countercurrent chromatography (HSCCC) using a two-phase solvent systems comprising ethyl acetate-n-butanol- methanol-water 2.4:2.6:0.2:4.8 (v/v) to yield holothurin A and echinoside A with purities 93.5 and 95.5%, respectively. The chemical structures were elucidated by ESIMS and NMR analysis.