4 research outputs found
Enhanced photocatalytic degradation of azo dye using rare-earth metal doped TiO2 under visible light irradiation
No full text547-553Lanthanum doped TiO2 nanoparticles (La doped TiO2) have been prepared by a sol-gel process using TiO(C4H9)4 as
raw material and are characterized using XRD, FT-IR, SEM-EDS, TEM and UV-DRS. The insertion of La ion in TiO2
lattice has been confirmed by SEM-EDS and XRD data. TEM studies have confirmed that La ions are uniformly doped over
TiO2 lattice. The band gap level of La doped TiO2 is decreased to 2.92 eV with a red shift due to charge transfer reaction
which is confirmed by UV-DRS. The photocatalytic activities of the synthesized nanoparticles are evaluated for the
degradation of Congo red dye (20 ppm) in an aqueous solution with La doped TiO2 (0.25 g) at pH= 6.3, under solar light
irradiation. The photocatalytic results confirmed that the La doped TiO2 show good photocatalytic activity and can be
considered as a promising photocatalyst for the degradation of organic pollutants in water. Due to the stability of La doped
TiO2 nanoparticles, it could be reused for more than five cycles reaching 100% degradation efficiency
Solar light driven transition metal codoped ZnO (Ag, Ni- codoped ZnO) photocatalyst for environmental remediation
No full text352-360Visible light efficient Ag, Ni-codoped ZnO photocatalyst has been synthesised in the nano form by co-precipitation and
sonochemical method using ZnSO4ꞏ7H2O as a precursor. The structural, morphological and elemental observations of
synthesised photocatalyst have been characterized using X-ray diffraction (XRD), FTIR, UV-DRS, SEM with EDX and
HRTEM analysis. Incorporation of metal ions into ZnO lattice caused a red shift in the absorption band thus extending its
absorption towards visible region through inhibition of electron hole recombination reaction and through the property of
surface plasmon resonance (SPR). However the addition of silver and nickel ions has modified the electronic and optical
properties of the photocatalyst thus improving the photocatalytic performance of the sample. The photocatalytic
performance of Ag, Ni-codoped ZnO nanoparticles have been tested for degradation of Direct Red 81 dye (DR-81), as
pollutant in aqueous solution. Under the optimum conditions (20 ppm dye and 10 mg/L photocatalyst), complete
mineralization of dye solution under study was achieved within 40min of time duration. The Ag, Ni-codoped ZnO
photocatalyst is thermally stable and efficient for five successive consecutive runs thus retaining its efficiency towards
degradation. The overall results thus obtained have suggested that a suitable method for the detoxification of environmental
pollutants emerging from industries
Enhanced photocatalytic activity of coupled ZnO/SnO2 nanocomposite under visible light for the degradation of Quinalphos in aqueous solution
No full text526-532Metal nanocomposite as photocatalyst plays a major role for treating organic and inorganic pollutants present in industrial effluent through photocatalytic process. In this study, the co-precipitation method has been demonstrated in the preparation of ZnO/SnO2nanocomposite. The catalytic behaviour of the ZnO/SnO2 is studied against Quinalphos pesticide under the illumination of direct sunlight at neutral pH. The photocatalytic performance of ZnO/SnO2nanocomposite is examined by loading 2 mg/L of the catalyst in 30 ppm of the Quinalphos solution to achieve 98 % degradation in thirty minutes. The structural and chemical compositional analysis of the prepared ZnO/SnO2nanocomposite has been characterised by X-ray diffraction pattern and FT-IR spectrum respectively. The morphological analysis of ZnO/SnO2 nanocomposite is done by scanning electron microscope (SEM). The UV-Visible absorption spectroscopy is used to examine the optical properties of ZnO/SnO2nanocomposite together with the photo degradation process of Quinalphos pesticide. The presence of oxygen vacancies and the fluorescence property of the prepared nanocomposite are detected by fluorimetric analysis. Degradation efficiency is estimated by COD and TOC measurements. Moreover, the stability and quality of the prepared ZnO/SnO2nanocomposite could be separated easily and utilised for multiple cycles with no change in its activity
Solar light driven transition metal codoped ZnO (Ag, Ni- codoped ZnO) photocatalyst for environmental remediation
Get PDF Visible light efficient Ag, Ni-codoped ZnO photocatalyst has been synthesised in the nano form by co-precipitation and sonochemical method using ZnSO4ꞏ7H2O as a precursor. The structural, morphological and elemental observations of synthesised photocatalyst have been characterized using X-ray diffraction (XRD), FTIR, UV-DRS, SEM with EDX and HRTEM analysis. Incorporation of metal ions into ZnO lattice caused a red shift in the absorption band thus extending its absorption towards visible region through inhibition of electron hole recombination reaction and through the property of surface plasmon resonance (SPR). However the addition of silver and nickel ions has modified the electronic and optical properties of the photocatalyst thus improving the photocatalytic performance of the sample. The photocatalytic performance of Ag, Ni-codoped ZnO nanoparticles have been tested for degradation of Direct Red 81 dye (DR-81), as pollutant in aqueous solution. Under the optimum conditions (20 ppm dye and 10 mg/L photocatalyst), complete mineralization of dye solution under study was achieved within 40min of time duration. The Ag, Ni-codoped ZnO photocatalyst is thermally stable and efficient for five successive consecutive runs thus retaining its efficiency towards degradation. The overall results thus obtained have suggested that a suitable method for the detoxification of environmental pollutants emerging from industries.
