Rare earth ortho-oxomolybdates of composition Ln2/aMoO4 （Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er and Y） were prepared by metathesis reaction. All these materials were characterized by powder X-ray diffraction, Fourier...Rare earth ortho-oxomolybdates of composition Ln2/aMoO4 （Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er and Y） were prepared by metathesis reaction. All these materials were characterized by powder X-ray diffraction, Fourier transform-infrared spectroscopy （FT-IR） and UV-Vis diffuse reflectance spectra. The Rietveld analysis of all the samples was carried out to obtain the unit cell parameters and reliability factors. All the materials were crystallized in tetragonal lattice with I41/a space group. The infrared spectra of all the samples were characterized by bands due to MoO42 units. The bandgap energies of all the samples were obtained from UV-Vis DRS spectra. The luminescence spectra of Ln2/3MoO4 （Ln=Pr, Eu and Dy） showed characteristic transitions of the rare earth ions. The visible light photocatalytic activity of all the samples was studied against degradation of methylene blue.展开更多
Potassium phosphatoantimonates, KSb2PO8 （KSbPO） and KSb2PO8-xNy （KSbPON）, are prepared by solidstate method. Urea is employed as a source of nitrogen for N-doping. Structural, morphological and optical properties ...Potassium phosphatoantimonates, KSb2PO8 （KSbPO） and KSb2PO8-xNy （KSbPON）, are prepared by solidstate method. Urea is employed as a source of nitrogen for N-doping. Structural, morphological and optical properties of both KSbPO and KSbPON are characterized by powder X-ray diffraction （PXRD）, scanning electron microscopy, energydispersive spectroscopy, Fourier transform infrared spectroscopy and UV-visible diffuse reflectance spectroscopy. Both samples are found to crystallize in a monoclinic lattice with Cc space group. The d-lines of KSbPO and KSbPON are refined by least square fitting the PXRD data, using POWD software to obtain their unit cell parameters. The bandgap energy （Eg） of both pristine and N-doped KSbPO is found from their Kubelka-Munk plot. The KSbPON/visible photocatalytic degradation of methylene blue and rhodamine B has been investigated in aqueous heterogeneous suspension. The generation of .OH in the presence of KSbPON during the photoreaction is verified by a fluorescence technique using terephthalic acid （TA） as a probe.展开更多
Substitutional doping of framework heteroatoms in photocatalysts is one ot the approaches tor harvesting visible light. The present work aims to utilize the visible light for photocatalytic degradation of organic poll...Substitutional doping of framework heteroatoms in photocatalysts is one ot the approaches tor harvesting visible light. The present work aims to utilize the visible light for photocatalytic degradation of organic pollutant by tailoring the bandgap energy of Li2VPO6 through nitrogen doping. Li2VPO6 and N-doped Li2VPO6 are prepared by solid- state method. These materials were characterized by powder X-ray diffraction, energy-dispersive spectra, Raman spectra, UV-Vis diffuse reflectance spectra （UV-Vis DRS）, and 31p MAS NMR. The absorption edge of N-doped Li2VPO6 iS shifted to longer wavelength region considerably. The photocatalytic activity was tested against the degradation of methylene blue. The higher visible light photocatalytic activity of N-doped Li2VPO6 compared to pristine Li2VPO6 was discussed. The catalysts are stable even after fourth cycle of photodegradation.展开更多
基金supported by Council of Scientific and Industrial Research(CSIR),New Delhi
文摘Rare earth ortho-oxomolybdates of composition Ln2/aMoO4 （Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er and Y） were prepared by metathesis reaction. All these materials were characterized by powder X-ray diffraction, Fourier transform-infrared spectroscopy （FT-IR） and UV-Vis diffuse reflectance spectra. The Rietveld analysis of all the samples was carried out to obtain the unit cell parameters and reliability factors. All the materials were crystallized in tetragonal lattice with I41/a space group. The infrared spectra of all the samples were characterized by bands due to MoO42 units. The bandgap energies of all the samples were obtained from UV-Vis DRS spectra. The luminescence spectra of Ln2/3MoO4 （Ln=Pr, Eu and Dy） showed characteristic transitions of the rare earth ions. The visible light photocatalytic activity of all the samples was studied against degradation of methylene blue.
文摘Potassium phosphatoantimonates, KSb2PO8 （KSbPO） and KSb2PO8-xNy （KSbPON）, are prepared by solidstate method. Urea is employed as a source of nitrogen for N-doping. Structural, morphological and optical properties of both KSbPO and KSbPON are characterized by powder X-ray diffraction （PXRD）, scanning electron microscopy, energydispersive spectroscopy, Fourier transform infrared spectroscopy and UV-visible diffuse reflectance spectroscopy. Both samples are found to crystallize in a monoclinic lattice with Cc space group. The d-lines of KSbPO and KSbPON are refined by least square fitting the PXRD data, using POWD software to obtain their unit cell parameters. The bandgap energy （Eg） of both pristine and N-doped KSbPO is found from their Kubelka-Munk plot. The KSbPON/visible photocatalytic degradation of methylene blue and rhodamine B has been investigated in aqueous heterogeneous suspension. The generation of .OH in the presence of KSbPON during the photoreaction is verified by a fluorescence technique using terephthalic acid （TA） as a probe.
基金Financial assistance from UGC-UPE New Delhi is gratefully acknowledged
文摘Substitutional doping of framework heteroatoms in photocatalysts is one ot the approaches tor harvesting visible light. The present work aims to utilize the visible light for photocatalytic degradation of organic pollutant by tailoring the bandgap energy of Li2VPO6 through nitrogen doping. Li2VPO6 and N-doped Li2VPO6 are prepared by solid- state method. These materials were characterized by powder X-ray diffraction, energy-dispersive spectra, Raman spectra, UV-Vis diffuse reflectance spectra （UV-Vis DRS）, and 31p MAS NMR. The absorption edge of N-doped Li2VPO6 iS shifted to longer wavelength region considerably. The photocatalytic activity was tested against the degradation of methylene blue. The higher visible light photocatalytic activity of N-doped Li2VPO6 compared to pristine Li2VPO6 was discussed. The catalysts are stable even after fourth cycle of photodegradation.
