Papers by Author: Pei Song Tang

Abstract: Using La (NO₃)₃·6H₂O, NH₄VO₃, citric acid as the main raw materials, nanocrystalline LaVO₄ sample was prepared by microwave method. The structure and morphology of sample were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible diffuse reflectance spectroscopy (DRS) and Fourier Transform Infrared (FT-IR) spectroscopy. The photocatalytic activity of LaVO₄ was studied for methyl orange (MO) used as simulated sewage. The XRD and SEM showed that the particle size of LaVO₄ was about 80-100 nm. The DRS showed that LaVO₄ had optical absorption onset of 356 nm, indicating the optical band gap of 3.48 eV. The FT-IR showed that LaVO₄ had vibration peaks of Fe-O and V-O bond. Under UV-light, the photocatalytic experiment indicated that the prepared LaVO₄ nanocrystalline had highly photocatalytic activity for degradation of methyl orange.

Abstract: Using La (NO₃)₃·6H₂O, TiCl₄ , and citric acid as the main raw materials, nanocrystalline La₂Ti₂O₇ samples were prepared by microwave assisted method. The structure and morphology of samples were characterized by thermogravimetric and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared (FT-IR) spectroscopy. The photocatalytic activity of La₂Ti₂O₇ was studied for methyl orange (MO) used as simulated sewage. It was found that the single phase La₂Ti₂O₇ could be obtained through the calcination of microwave processed La₂Ti₂O₇ precursors at 600 °C. The resulted product had an approximate spherical shape and average grain size of 50 nm in diameter. Under UV light, the photocatalytic experiment indicated that the prepared La₂Ti₂O₇ nanocrystalline had high photocatalytic activity for degradation of methyl orange.

Abstract: Using Fe (NO₃)₃⋅9H₂O, Y(NO₃)₃⋅6H₂O and citric acid as the main raw material, the YFeO₃ nanoparticles were synthesized by ultrasonic assisted process and calcination. The YFeO₃ nanoparticles were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). The results show that the perovskite structureYFeO₃ (YFeO₃-800) can be obtained through the calcination of ultrasonic processed YFeO₃ precursors at 800 °C, and the resulting product has a particle size of 70 nm and an optical band gap of 2.0 eV. Consequently, the YFeO₃-800 nanoparticles show high photocatalytic activity for decomposition of methyl orange under visible-light irradiation.

Abstract: TbFeO₃ nanoparticles were synthesized using Tb₄O₇ and Fe (NO₃)₃·9H₂O as the main raw material by a one-step microwave process. The prepared nanoparticles were characterized by thermogravimetric and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). XRD and SEM demonstrate the successful synthesis of single phase TbFeO₃ and an average grain size of 40-100 nm in diameter. The single phase structure of TbFeO₃ was yet maintained after calcination at 800 °C. The photocatalytic experiment shows the high visible-light photocatalytic activity for the decomposition of methyl orange.

Abstract: A supported photocatalyst zinc phthalocyanine-calcium alginate gel beads (Zn-MPc-SA) was prepared through the mixture of water-soluble zinc phthalocyanine (Zn-MPc) and sodium alginate was drip into 5% (w/v) CaCl₂ solution. The Zn-MPc-SA was characterized by IR. Methyl orange was selected as a substrate to investigate the photocatalytic activity of Zn-MPc-SA. The results shown that: the surplus of methyl orange was 22.05% at the condition of pH 3, methyl orange 10mg/L 25mL, H₂O₂ 50μL, Zn-MPc-SA 0.1460g and visible light irradiation for 3h. Zn-MPc-SA remains efficient in repetitive test cycles with no obvious degradation of catalytic activity. The reaction mechanism was likely to involve free hydroxyl radicals.

Abstract: Using Fe (NO₃)₃9H₂O, Y(NO₃)₃6H₂O and polyvinyl alcohol as the main raw material, the YFeO₃ nanoparticles were prepared by a microwave process. The YFeO₃ nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). The results show that the perovskite structureYFeO₃ can be obtained, and the resulting product has a particle size of 70 nm and an optical band gap of 2.4 eV. The recovery of YFeO₃ photocatalysts was performed by the photocatalytic experiment of load YFeO₃. It is found that YFeO₃ nanocrystalline photocatalysts can be efficiently recovered by magnetic polymer film load.

Abstract: Using Yb(NO₃)₃•6H₂O and Fe(NO₃)₃•9H₂O as raw material, the YbFeO₃ nanoparticles were synthesized by microwave assisted method. The YbFeO₃ nanoparticles were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). It was found that the prepared YbFeO₃ show an average grain size of 80 nm in diameter, and strong visible-light absorption with absorption onset of 608 nm, indicating a narrow optical band gap of 2.04eV. Consequently, the YbFeO₃ nanoparticles show high photocatalytic activity for decomposition of methylene blue under visible-light irradiation.

Abstract: The C₃N₄ was synthesized by directly thermal decomposition melamine in N₂ atmosphere furnace. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectroscopy (DRS). The results show that C₃N₄ indicates the typical slate-like, stacked lamellar texture of about 1μm in diameter, and a band gap of about 2.78 eV. The photocatalytic experiment shows the good photocatalytic activity for the decomposition of methyl orange (MO) under visible-light irradiation, which is attributed to the strong visible-light absorption.

Abstract: The single phase BiTaO₄ was synthesized using Ta₂O₅ and Bi(NO₃)₃ as main raw materials by precipitation process. The products were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). The results show that BiTaO₄ was triclinic crystal with average particle size 100nm, and a band gap of about 2.77 eV. The photocatalytic experiment of BiTaO₄ shows the good photocatalytic activity for the decomposition of methylene blue under visible-light irradiation.

Abstract: The YVO₄ was synthesized by microwave assisted process. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance spectroscopy (DRS), thermogravimetry and differential thermal analysis (TG-DTA) and Brunauer-Emmett-Teller (BET) method. The results show that YVO₄ was tetragonal crystal, particle size of 50 to 80 nm, band gap of 3.3 eV and surface area of 18.6m²/g. The photocatalytic experiment of YVO₄ shows the high photocatalytic activity for the decomposition of methyl orange under UV-light irradiation.