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Patrick Da Costa - One of the best experts on this subject based on the ideXlab platform.

  • photocatalytic degradation of Methyl Green dye in aqueous solution over natural clay supported zno tio2 catalysts
    Journal of Photochemistry and Photobiology A-chemistry, 2016
    Co-Authors: Haithem Bel Hadjltaief, Mourad Ben Zina, Patrick Da Costa, Maria Elena Galvez
    Abstract:

    A ZnO–TiO2/clay photcatalyst was prepared using a natural Tunisian clay as support. Its activity was assayed in the photocatalytic degradation of Methyl Green in aqueous solutions, in the presence of UVA irradiation. The photocatalyst was synthesized using a metal organic chemical vapor deposition (MOCVD) with Ti (OPri)4 deposed on the natural Na+–clay, followed by a modified sol–gel synthesis method for introduction. The sample was then characterized by scanning electronic microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption, X-ray diffraction (XRD) and titration for the determination of the zero point charge (pHZPC). The activity tests showed that the photodegradation efficiency for ZnO–TiO2/clay is higher than for the TiO2/clay catalyst, clearly pointing to a promoting effect of ZnO. The influence of operational parameters such as pH, catalyst dosage, initial dye concentration, UV irradiation intensity, as well as the influence of the presence of different oxidants was evaluated. Almost complete mineralization was obtained upon 30 min of light irradiation in the presence of the ZnO–TiO2/clay catalyst.

  • Photocatalytic degradation of Methyl Green dye in aqueous solution over natural clay-supported ZnO–TiO2 catalysts
    Journal of Photochemistry and Photobiology A: Chemistry, 2016
    Co-Authors: Haithem Bel Hadjltaief, Mourad Ben Zina, Maria Elena Galvez, Patrick Da Costa
    Abstract:

    A ZnO–TiO2/clay photcatalyst was prepared using a natural Tunisian clay as support. Its activity was assayed in the photocatalytic degradation of Methyl Green in aqueous solutions, in the presence of UVA irradiation. The photocatalyst was synthesized using a metal organic chemical vapor deposition (MOCVD) with Ti (OPri)4 deposed on the natural Na+–clay, followed by a modified sol–gel synthesis method for introduction. The sample was then characterized by scanning electronic microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption, X-ray diffraction (XRD) and titration for the determination of the zero point charge (pHZPC). The activity tests showed that the photodegradation efficiency for ZnO–TiO2/clay is higher than for the TiO2/clay catalyst, clearly pointing to a promoting effect of ZnO. The influence of operational parameters such as pH, catalyst dosage, initial dye concentration, UV irradiation intensity, as well as the influence of the presence of different oxidants was evaluated. Almost complete mineralization was obtained upon 30 min of light irradiation in the presence of the ZnO–TiO2/clay catalyst.

  • Titanium Dioxide Supported on Different Porous Materials as Photocatalyst for the Degradation of Methyl Green in Wastewaters
    Advances in Materials Science and Engineering, 2015
    Co-Authors: Haithem Bel Hadjltaief, Abdessalem Omri, Mourad Ben Zina, Patrick Da Costa, Maria Elena Galvez
    Abstract:

    TiO2nanoparticles were immobilized on two porous materials used as catalyst supports, namely, activated carbon (AC) and natural clay (NC), through an impregnation process using TiO2(P25) as precursor. The so-prepared composite materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), and nitrogen physisorption, that is, Brunauer-Emmett-Teller (BET) surface area determination. SEM and TEM observation evidenced that TiO2was deposited on AC and NC surface. XRD results confirmed that TiO2existed in a mixture of anatase and rutile phases. The specific surface area of photocatalysts decreased drastically in comparison with the original materials. The photocatalytic activity of these materials was assayed in the oxidation of Methyl Green (MG) dye in aqueous medium under UV irradiation. TiO2/AC exhibited higher photocatalytic oxidation activity than TiO2at neutral pH. Total mineralization of MG was confirmed by means of COD analysis, pointing to these materials as an efficient, cost-effective, and environment friendly alternative for water treatment.

  • Research Article Titanium Dioxide Supported on Different Porous Materials as Photocatalyst for the Degradation of Methyl Green in Wastewaters
    Advances in Materials Science and Engineering, 2015
    Co-Authors: Haithem Bel Hadjltaief, Abdessalem Omri, Patrick Da Costa, Mourad Ben Zina, Maria Elena Galvez
    Abstract:

    TiO 2 nanoparticles were immobilized on two porous materials used as catalyst supports, namely, activated carbon (AC) and natural clay (NC), through an impregnation process using TiO 2 (P25) as precursor. The so-prepared composite materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), and nitrogen physisorption, that is, Brunauer-Emmett-Teller (BET) surface area determination. SEM and TEM observation evidenced that TiO 2 was deposited on AC and NC surface. XRD results confirmed that TiO 2 existed in a mixture of anatase and rutile phases. The specific surface area of photocatalysts decreased drastically in comparison with the original materials. The photocatalytic activity of these materials was assayed in the oxidation of Methyl Green (MG) dye in aqueous medium under UV irradiation. TiO 2 /AC exhibited higher photocatalytic oxidation activity than TiO 2 at neutral pH. Total mineralization of MG was confirmed by means of COD analysis, pointing to these materials as an efficient, cost-effective, and environment friendly alternative for water treatment.

Maria Elena Galvez - One of the best experts on this subject based on the ideXlab platform.

  • photocatalytic degradation of Methyl Green dye in aqueous solution over natural clay supported zno tio2 catalysts
    Journal of Photochemistry and Photobiology A-chemistry, 2016
    Co-Authors: Haithem Bel Hadjltaief, Mourad Ben Zina, Patrick Da Costa, Maria Elena Galvez
    Abstract:

    A ZnO–TiO2/clay photcatalyst was prepared using a natural Tunisian clay as support. Its activity was assayed in the photocatalytic degradation of Methyl Green in aqueous solutions, in the presence of UVA irradiation. The photocatalyst was synthesized using a metal organic chemical vapor deposition (MOCVD) with Ti (OPri)4 deposed on the natural Na+–clay, followed by a modified sol–gel synthesis method for introduction. The sample was then characterized by scanning electronic microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption, X-ray diffraction (XRD) and titration for the determination of the zero point charge (pHZPC). The activity tests showed that the photodegradation efficiency for ZnO–TiO2/clay is higher than for the TiO2/clay catalyst, clearly pointing to a promoting effect of ZnO. The influence of operational parameters such as pH, catalyst dosage, initial dye concentration, UV irradiation intensity, as well as the influence of the presence of different oxidants was evaluated. Almost complete mineralization was obtained upon 30 min of light irradiation in the presence of the ZnO–TiO2/clay catalyst.

  • Photocatalytic degradation of Methyl Green dye in aqueous solution over natural clay-supported ZnO–TiO2 catalysts
    Journal of Photochemistry and Photobiology A: Chemistry, 2016
    Co-Authors: Haithem Bel Hadjltaief, Mourad Ben Zina, Maria Elena Galvez, Patrick Da Costa
    Abstract:

    A ZnO–TiO2/clay photcatalyst was prepared using a natural Tunisian clay as support. Its activity was assayed in the photocatalytic degradation of Methyl Green in aqueous solutions, in the presence of UVA irradiation. The photocatalyst was synthesized using a metal organic chemical vapor deposition (MOCVD) with Ti (OPri)4 deposed on the natural Na+–clay, followed by a modified sol–gel synthesis method for introduction. The sample was then characterized by scanning electronic microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption, X-ray diffraction (XRD) and titration for the determination of the zero point charge (pHZPC). The activity tests showed that the photodegradation efficiency for ZnO–TiO2/clay is higher than for the TiO2/clay catalyst, clearly pointing to a promoting effect of ZnO. The influence of operational parameters such as pH, catalyst dosage, initial dye concentration, UV irradiation intensity, as well as the influence of the presence of different oxidants was evaluated. Almost complete mineralization was obtained upon 30 min of light irradiation in the presence of the ZnO–TiO2/clay catalyst.

  • Titanium Dioxide Supported on Different Porous Materials as Photocatalyst for the Degradation of Methyl Green in Wastewaters
    Advances in Materials Science and Engineering, 2015
    Co-Authors: Haithem Bel Hadjltaief, Abdessalem Omri, Mourad Ben Zina, Patrick Da Costa, Maria Elena Galvez
    Abstract:

    TiO2nanoparticles were immobilized on two porous materials used as catalyst supports, namely, activated carbon (AC) and natural clay (NC), through an impregnation process using TiO2(P25) as precursor. The so-prepared composite materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), and nitrogen physisorption, that is, Brunauer-Emmett-Teller (BET) surface area determination. SEM and TEM observation evidenced that TiO2was deposited on AC and NC surface. XRD results confirmed that TiO2existed in a mixture of anatase and rutile phases. The specific surface area of photocatalysts decreased drastically in comparison with the original materials. The photocatalytic activity of these materials was assayed in the oxidation of Methyl Green (MG) dye in aqueous medium under UV irradiation. TiO2/AC exhibited higher photocatalytic oxidation activity than TiO2at neutral pH. Total mineralization of MG was confirmed by means of COD analysis, pointing to these materials as an efficient, cost-effective, and environment friendly alternative for water treatment.

  • Research Article Titanium Dioxide Supported on Different Porous Materials as Photocatalyst for the Degradation of Methyl Green in Wastewaters
    Advances in Materials Science and Engineering, 2015
    Co-Authors: Haithem Bel Hadjltaief, Abdessalem Omri, Patrick Da Costa, Mourad Ben Zina, Maria Elena Galvez
    Abstract:

    TiO 2 nanoparticles were immobilized on two porous materials used as catalyst supports, namely, activated carbon (AC) and natural clay (NC), through an impregnation process using TiO 2 (P25) as precursor. The so-prepared composite materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), and nitrogen physisorption, that is, Brunauer-Emmett-Teller (BET) surface area determination. SEM and TEM observation evidenced that TiO 2 was deposited on AC and NC surface. XRD results confirmed that TiO 2 existed in a mixture of anatase and rutile phases. The specific surface area of photocatalysts decreased drastically in comparison with the original materials. The photocatalytic activity of these materials was assayed in the oxidation of Methyl Green (MG) dye in aqueous medium under UV irradiation. TiO 2 /AC exhibited higher photocatalytic oxidation activity than TiO 2 at neutral pH. Total mineralization of MG was confirmed by means of COD analysis, pointing to these materials as an efficient, cost-effective, and environment friendly alternative for water treatment.

Haithem Bel Hadjltaief - One of the best experts on this subject based on the ideXlab platform.

  • photocatalytic degradation of Methyl Green dye in aqueous solution over natural clay supported zno tio2 catalysts
    Journal of Photochemistry and Photobiology A-chemistry, 2016
    Co-Authors: Haithem Bel Hadjltaief, Mourad Ben Zina, Patrick Da Costa, Maria Elena Galvez
    Abstract:

    A ZnO–TiO2/clay photcatalyst was prepared using a natural Tunisian clay as support. Its activity was assayed in the photocatalytic degradation of Methyl Green in aqueous solutions, in the presence of UVA irradiation. The photocatalyst was synthesized using a metal organic chemical vapor deposition (MOCVD) with Ti (OPri)4 deposed on the natural Na+–clay, followed by a modified sol–gel synthesis method for introduction. The sample was then characterized by scanning electronic microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption, X-ray diffraction (XRD) and titration for the determination of the zero point charge (pHZPC). The activity tests showed that the photodegradation efficiency for ZnO–TiO2/clay is higher than for the TiO2/clay catalyst, clearly pointing to a promoting effect of ZnO. The influence of operational parameters such as pH, catalyst dosage, initial dye concentration, UV irradiation intensity, as well as the influence of the presence of different oxidants was evaluated. Almost complete mineralization was obtained upon 30 min of light irradiation in the presence of the ZnO–TiO2/clay catalyst.

  • Photocatalytic degradation of Methyl Green dye in aqueous solution over natural clay-supported ZnO–TiO2 catalysts
    Journal of Photochemistry and Photobiology A: Chemistry, 2016
    Co-Authors: Haithem Bel Hadjltaief, Mourad Ben Zina, Maria Elena Galvez, Patrick Da Costa
    Abstract:

    A ZnO–TiO2/clay photcatalyst was prepared using a natural Tunisian clay as support. Its activity was assayed in the photocatalytic degradation of Methyl Green in aqueous solutions, in the presence of UVA irradiation. The photocatalyst was synthesized using a metal organic chemical vapor deposition (MOCVD) with Ti (OPri)4 deposed on the natural Na+–clay, followed by a modified sol–gel synthesis method for introduction. The sample was then characterized by scanning electronic microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption, X-ray diffraction (XRD) and titration for the determination of the zero point charge (pHZPC). The activity tests showed that the photodegradation efficiency for ZnO–TiO2/clay is higher than for the TiO2/clay catalyst, clearly pointing to a promoting effect of ZnO. The influence of operational parameters such as pH, catalyst dosage, initial dye concentration, UV irradiation intensity, as well as the influence of the presence of different oxidants was evaluated. Almost complete mineralization was obtained upon 30 min of light irradiation in the presence of the ZnO–TiO2/clay catalyst.

  • Titanium Dioxide Supported on Different Porous Materials as Photocatalyst for the Degradation of Methyl Green in Wastewaters
    Advances in Materials Science and Engineering, 2015
    Co-Authors: Haithem Bel Hadjltaief, Abdessalem Omri, Mourad Ben Zina, Patrick Da Costa, Maria Elena Galvez
    Abstract:

    TiO2nanoparticles were immobilized on two porous materials used as catalyst supports, namely, activated carbon (AC) and natural clay (NC), through an impregnation process using TiO2(P25) as precursor. The so-prepared composite materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), and nitrogen physisorption, that is, Brunauer-Emmett-Teller (BET) surface area determination. SEM and TEM observation evidenced that TiO2was deposited on AC and NC surface. XRD results confirmed that TiO2existed in a mixture of anatase and rutile phases. The specific surface area of photocatalysts decreased drastically in comparison with the original materials. The photocatalytic activity of these materials was assayed in the oxidation of Methyl Green (MG) dye in aqueous medium under UV irradiation. TiO2/AC exhibited higher photocatalytic oxidation activity than TiO2at neutral pH. Total mineralization of MG was confirmed by means of COD analysis, pointing to these materials as an efficient, cost-effective, and environment friendly alternative for water treatment.

Mourad Ben Zina - One of the best experts on this subject based on the ideXlab platform.

  • photocatalytic degradation of Methyl Green dye in aqueous solution over natural clay supported zno tio2 catalysts
    Journal of Photochemistry and Photobiology A-chemistry, 2016
    Co-Authors: Haithem Bel Hadjltaief, Mourad Ben Zina, Patrick Da Costa, Maria Elena Galvez
    Abstract:

    A ZnO–TiO2/clay photcatalyst was prepared using a natural Tunisian clay as support. Its activity was assayed in the photocatalytic degradation of Methyl Green in aqueous solutions, in the presence of UVA irradiation. The photocatalyst was synthesized using a metal organic chemical vapor deposition (MOCVD) with Ti (OPri)4 deposed on the natural Na+–clay, followed by a modified sol–gel synthesis method for introduction. The sample was then characterized by scanning electronic microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption, X-ray diffraction (XRD) and titration for the determination of the zero point charge (pHZPC). The activity tests showed that the photodegradation efficiency for ZnO–TiO2/clay is higher than for the TiO2/clay catalyst, clearly pointing to a promoting effect of ZnO. The influence of operational parameters such as pH, catalyst dosage, initial dye concentration, UV irradiation intensity, as well as the influence of the presence of different oxidants was evaluated. Almost complete mineralization was obtained upon 30 min of light irradiation in the presence of the ZnO–TiO2/clay catalyst.

  • Photocatalytic degradation of Methyl Green dye in aqueous solution over natural clay-supported ZnO–TiO2 catalysts
    Journal of Photochemistry and Photobiology A: Chemistry, 2016
    Co-Authors: Haithem Bel Hadjltaief, Mourad Ben Zina, Maria Elena Galvez, Patrick Da Costa
    Abstract:

    A ZnO–TiO2/clay photcatalyst was prepared using a natural Tunisian clay as support. Its activity was assayed in the photocatalytic degradation of Methyl Green in aqueous solutions, in the presence of UVA irradiation. The photocatalyst was synthesized using a metal organic chemical vapor deposition (MOCVD) with Ti (OPri)4 deposed on the natural Na+–clay, followed by a modified sol–gel synthesis method for introduction. The sample was then characterized by scanning electronic microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption, X-ray diffraction (XRD) and titration for the determination of the zero point charge (pHZPC). The activity tests showed that the photodegradation efficiency for ZnO–TiO2/clay is higher than for the TiO2/clay catalyst, clearly pointing to a promoting effect of ZnO. The influence of operational parameters such as pH, catalyst dosage, initial dye concentration, UV irradiation intensity, as well as the influence of the presence of different oxidants was evaluated. Almost complete mineralization was obtained upon 30 min of light irradiation in the presence of the ZnO–TiO2/clay catalyst.

  • Titanium Dioxide Supported on Different Porous Materials as Photocatalyst for the Degradation of Methyl Green in Wastewaters
    Advances in Materials Science and Engineering, 2015
    Co-Authors: Haithem Bel Hadjltaief, Abdessalem Omri, Mourad Ben Zina, Patrick Da Costa, Maria Elena Galvez
    Abstract:

    TiO2nanoparticles were immobilized on two porous materials used as catalyst supports, namely, activated carbon (AC) and natural clay (NC), through an impregnation process using TiO2(P25) as precursor. The so-prepared composite materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), and nitrogen physisorption, that is, Brunauer-Emmett-Teller (BET) surface area determination. SEM and TEM observation evidenced that TiO2was deposited on AC and NC surface. XRD results confirmed that TiO2existed in a mixture of anatase and rutile phases. The specific surface area of photocatalysts decreased drastically in comparison with the original materials. The photocatalytic activity of these materials was assayed in the oxidation of Methyl Green (MG) dye in aqueous medium under UV irradiation. TiO2/AC exhibited higher photocatalytic oxidation activity than TiO2at neutral pH. Total mineralization of MG was confirmed by means of COD analysis, pointing to these materials as an efficient, cost-effective, and environment friendly alternative for water treatment.

Anjali Narwal - One of the best experts on this subject based on the ideXlab platform.

  • Detection of Apoptosis in Leukoplakia and Oral Squamous Cell Carcinoma using Methyl Green Pyronin and Hematoxylin and Eosin.
    Iranian journal of pathology, 2020
    Co-Authors: Pooja Sharma, Anjali Narwal, Mala Kamboj
    Abstract:

    Background & ObjectiveCell population and turnover are controlled by a balance between cell proliferation and apoptosis. Detection of apoptosis in oral cancer contributes to its better prognosis and improved management. This study aimed to quantify apoptotic cells in leukoplakia and oral squamous cell carcinoma (OSCC) using Methyl Green-pyronin (MGP) and hematoxylin and eosin (H & E) staining.MethodsThe sample included a total of 130 subjects (comprising 108 males and 22 females). Formalin fixed and paraffin embedded tissues were used and categorized into three groups of normal oral mucosa (n=10), leukoplakia with dysplasia (n=60), and OSCC (n=60). The number of apoptotic cells and apoptotic index (AI) were calculated after staining with MGP and routine H & E stained slides.ResultsMGP stained the condensed chromatin of apoptotic cells. Statistically significant difference (P≤0.001) was observed among various study groups in terms of numbers of AI and apoptotic cells. Also, AI increased with increasing grades of dysplasia, and it was the highest in well differentiated OSCC. Results were statistically significant in both H & E and MGP stained sections (P≤0.001). A good correlation was found between MGP and H & E staining results.ConclusionMGP is more specific and can lead to intense staining for chromatin in apoptotic cells. Accordingly, it can provide a good alternative to H&E in identifying apoptotic cells.

  • The Diagnostic Role of Methyl Green-Pyronin Y Staining in Oral Leukoplakia and Oral Squamous Cell Carcinoma: An Exfoliative Cytology-Based Cytomorphometric Analysis.
    Acta cytologica, 2019
    Co-Authors: Rahul Kumar Raman, Mala Kamboj, Anjali Narwal
    Abstract:

    Background: Oral exfoliative cytology is a noninvasive and nonpainful technique for early diagnosis of oral potentially malignant disorders and oral cancer, and the use of cytomorphometry ameliorates its diagnostic reliability. The objective of the present study was to analyze Methyl Green-pyronin Y (MGP)-stained oral exfoliated cells (OECs) of oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC) by cytomorphometry. Materials and Method: An observational study was conducted on 150 individuals equally divided into three groups: normal mucosa, OL, and OSCC. Smears were prepared from OECs and stained with MGP. Cytomorphometry was done for 100 cells per subject, and various cell and nuclear parameters were measured and calculated. Results: The Kruskal-Wallis test with post hoc correlation showed significant differences in nucleus and cell diameter (ND, CD), nucleus and cell area (NA, CA), nucleus and cell perimeter (NP, CP), and nucleus to cytoplasmic (N:C) ratio for diameter, perimeter, and area. Spearman’s ρ correlation of various N:C ratio methods showed good correlation between N:C perimeter and diameter ratio, N:C diameter and ellipse ratio, and N:C area and ellipse ratio. Additional morphological factors showed significant relations for both cell and nuclear regularity factor, shape factor, and nuclear contour index. Discussion: MGP-based cytomorphometry showed a significant decrease in CD, CA, and CP and increase in ND, NA, NP, and N:C ratio from normal mucosa to OL and OSCC. MGP proved its worth as an effective stain for OECs, despite its strict standardization.