Synthesis, characterization, luminescence and photocatalytic studies of layered perovskites NaMMgWO6 (M = La, Pr, Sm)

The synthesis, characterization, optical and photocatalytic studies of AA'BB'X6 type perovskites, NaMMgWO6 (M = La, Pr, Sm), which have an ordering of both the cation sub-lattices, is reported.  The obtained NaMMgWO6 materials have been prepared using ethylene glycol assisted gel-burning method and characterized by X-ray diffraction patterns, UV-vis diffused reflectance spectra, scanning electron microscopy, Fourier transformation infrared spectra, energy dispersive spectra and fluorescence spectra. The photocatalytic dye degradation performance of the as-synthesized perovskites has been evaluated with methylene blue and methyl violet as model water pollutants using radical quenchers

Photocatalytic and DC conductivity studies of proton exchanged KAl0.33W1.67O6 and its application in Pb2+ removal

The proton exchanged metal oxide of composition HAl0.33Te1.67O6 (HAW) is synthesized by ion exchange method at room temperature and characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and UV-vis diffuse reflectance spectroscopy. Presence of water content in the HAW has been examined by thermogravimetric analysis. Conductivity and photocatalytic properties of HAW are compared with those of its parent KAl0.33W1.67O6 (KAW). HAl0.33W1.67O6 shows higher conductivity and photocatalytic activity for the degradation of methyl blue and Rhodamine B under visible light irradiation. Participation of hydroxyl radicals in the photocatalytic dye degradation has been investigated by photoluminescence studies using terephthalic acid as probe. The removal of Pb2+ from an aqueous solution of Pb(NO3)2 using pristine KAl0.33W1.67O6 is also reported

Photocatalytic degradation of methylene blue and methyl violet using cation doped (Sn2+ and Ag+) barium tellurite phosphate, Ba2TeO(PO4)2

One-dimensional barium tellurite phosphate of composition, Ba2TeO(PO4)2, is prepared by solid state method. Tin (Sn2+) and silver (Ag+) doped Ba2TeO(PO4)2 materials are prepared via a facile room temperature ion-exchange method. Structural, morphological, and optical properties of all the materials are characterized by powder X-ray diffraction, FT-IR, SEM-EDS, and UV-visible diffuse reflectance spectroscopy techniques. The band gap energy (Eg) of all the phosphates is deduced from their Kubelka–Munk (KM) plot. The synthesized phosphates are used as photocatalyst for the degradation of methylene blue and methyl violet dyes under the visible light irradiation. The systematic degradation pathways of the dyes are studied in the presence of all the photocatalysts and scavengers. The stability and reusability of all the photocatalyst are assessed by the cycling runs in the photodegradation experiment.

Low-temperature synthesis of Cr₂WO₆ and its enhanced photocatalytic activity by N-doping

32-39Nano sized inverse trirutiles of composition Cr2WO6 and N-doped Cr2WO6 have been prepared by sol-gel and solid state methods respectively. Urea has been used as a source of nitrogen for N-doping. These trirutiles have been characterized by powder X-ray diffraction (PXRD), FT-IR, TGA, scanning electron microscopy (SEM), energy dispersive spectra (EDS), and UV-visible diffuse reflectance spectroscopy (UV-vis DRS). N-doped Cr2WO6 is crystallized in the tetragonal lattice with space group P42/mnm (136). The bandgap energy of both parent and N-doped materials is deduced from their UV-visible DRS profiles. The photocatalytic degradation of methylene blue and methyl violet aqueous solutions have been investigated using these oxides. Compared to the parent material, nitrogen doped Cr2WO6 exhibits ~ 30% and ~ 20 % increase in visible light-induced photo-degradation of the methylene blue (MB) and methyl violet (MV), respectively

Synthesis, characterization, luminescence and photocatalytic studies of layered perovskites NaMMgWO₆ (M = La, Pr, Sm)

435-443The synthesis, characterization, optical and photocatalytic studies of AA'BB'X6 type perovskites, NaMMgWO6 (M = La, Pr, Sm), which have an ordering of both the cation sub-lattices, is reported.  The obtained NaMMgWO6 materials have been prepared using ethylene glycol assisted gel-burning method and characterized by X-ray diffraction patterns, UV-vis diffused reflectance spectra, scanning electron microscopy, Fourier transformation infrared spectra, energy dispersive spectra and fluorescence spectra. The photocatalytic dye degradation performance of the as-synthesized perovskites has been evaluated with methylene blue and methyl violet as model water pollutants using radical quenchers

Photocatalytic and DC conductivity studies of proton exchanged KAl_0.33W_1.67O₆ and its application in Pb²⁺ removal

270-277The proton exchanged metal oxide of composition HAl0.33Te1.67O6 (HAW) is synthesized by ion exchange method at room temperature and characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and UV-vis diffuse reflectance spectroscopy. Presence of water content in the HAW has been examined by thermogravimetric analysis. Conductivity and photocatalytic properties of HAW are compared with those of its parent KAl0.33W1.67O6 (KAW). HAl0.33W1.67O6 shows higher conductivity and photocatalytic activity for the degradation of methyl blue and Rhodamine B under visible light irradiation. Participation of hydroxyl radicals in the photocatalytic dye degradation has been investigated by photoluminescence studies using terephthalic acid as probe. The removal of Pb2+ from an aqueous solution of Pb(NO3)2 using pristine KAl0.33W1.67O6 is also reported

<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Photocatalytic degradation of methylene blue and methyl violet using cation doped (Sn²⁺ and Ag⁺) barium tellurite phosphate, Ba₂TeO(PO₄)₂</span>

9-15One-dimensional barium tellurite phosphate of composition, Ba2TeO(PO4)2, is prepared by solid state method. Tin (Sn2+) and silver (Ag+) doped Ba2TeO(PO4)2 materials are prepared via a facile room temperature ion-exchange method. Structural, morphological, and optical properties of all the materials are characterized by powder X-ray diffraction, FT-IR, SEM-EDS, and UV-visible diffuse reflectance spectroscopy techniques. The band gap energy (Eg) of all the phosphates is deduced from their Kubelka–Munk (KM) plot. The synthesized phosphates are used as photocatalyst for the degradation of methylene blue and methyl violet dyes under the visible light irradiation. The systematic degradation pathways of the dyes are studied in the presence of all the photocatalysts and scavengers. The stability and reusability of all the photocatalyst are assessed by the cycling runs in the photodegradation experiment

Synthesis, characterization and photocatalytic activity studies of tellurium containing defect pyrochlores, MSn_0.5Te_1.5O₆ (M = K, Ag, Cu_0.5 and Sn_0.5)

1174-1181Four new metal tin tellurites, MSn0.5Te1.5O6 (M = K, Ag, Cu0.5 and Sn0.5), have been synthesized by standard solid-state and facile ion exchange reactions and characterized by powder X-ray diffraction, FTIR, SEM-EDS and UV-vis diffuse reflectance spectroscopic techniques. All the compositions crystallize in cubic lattice with Fdmspace group, and are isomorphous with KTi0.5Te1.5O6. The photocatalytic activity of the as prepared materials for methylene blue and methyl violet degradation has been investigated under visible light irradiation. The AgSn0.5Te1.5O6 photocatalyst exhibits higher photocatalytic activity than MSn0.5Te1.5O6 (M = K, Cu0.5 and Sn0.5) for photodegradation of methylene blue and methyl violet. The higher photocatalytic performance of AgSn0.5Te1.5O6 is ascribed to its low band gap energy, which endows it with a very strong photooxidation ability to produce OH● and O2●- radicals as active species. The catalyst stability and mechanism of photocatalysis is also discussed