Visible light induced photoreduction of methyl orange by N-doped mesoporous titania

• Published in: Applied catalysis. A, General Vol. 357; no. 1; pp. 26 - 33
• Main Authors: Joshi, Meenal M., Labhsetwar, Nitin K., Mangrulkar, Priti A., Tijare, Saumitra N., Kamble, Sanjay P., Rayalu, Sadhana S.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 31.03.2009; Elsevier
• Subjects: Biopolymer; Catalysis; Chemistry; Chitosan; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; MO photoreduction; N-doped mesoporous titania; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Porous materials; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Visible active photocatalyst; N-doped mesoporous titania; Chitosan; MO photoreduction; Visible active photocatalyst; Biopolymer; Stoichiometry; Binary compound; Incorporation; Dyes; X ray; Porous material; Precursor; Template; Chemical reduction; Photoelectron spectrometry; Hydrazine; Scanning electron microscopy; Composition; Photocatalysis; Transition element compounds; Nitrogen; X ray diffraction; Mesoporosity; Ammonium hydroxide; Infrared spectrometry; Heterogeneous catalysis; Titanium oxide
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2008.12.030

N-doped mesoporous titania was synthesized using templating method. Biopolymer chitosan was used as a template and also as a nitrogen source along with ammonium hydroxide. Three different types of N-doped mesoporous titania were synthesized by varying composition of chitosan and titania precursor. These photocatalysts were characterized using XRD, BET-SA, FTIR, UV-DRS, SEM–EDX and XPS analysis. The photocatalytic activity of mesoporous titania was studied by methyl orange (MO) photoreduction reaction. From the experimental results it was observed that the N-doped mesoporous titania (1:2) gives the highest photocatalytic reduction of MO as compared to N-doped mesoporous titania prepared with (1:1) and (1:3) stoichiometry. This could be due to the optimal level of ‘N’ incorporation in the N-doped mesoporous titania (1:2). Photocatalysts reduce the MO dye into derivative of hydrazine. Photoactivity of N-doped mesoporous titania (1:2) is 1.0721 mg of MO reduced per g of TiO 2 vis-à-vis 0.508 mg of MO reduced per g of TiO 2 for Degussa P25 photocatalyst. The effect of various operating parameters like photocatalyst loading, initial concentration and intensity of light also has been studied. N-doped mesoporous titania was synthesized using templating method. Biopolymer chitosan was used as a template and also as a nitrogen source along with ammonium hydroxide. Three different types of N-doped mesoporous titania were synthesized by varying composition of chitosan and titania precursor. These photocatalysts were characterized using XRD, BET-SA, FTIR, UV-DRS, SEM–EDX and XPS analysis. The photocatalytic activity of mesoporous titania was studied by methyl orange (MO) photoreduction reaction. From the experimental results it was observed that the N-doped mesoporous titania (1:2) gives the highest photocatalytic reduction of MO as compared to N-doped mesoporous titania prepared with (1:1) and (1:3) stoichiometry. This could be due to the optimal level of ‘N’ incorporation in the N-doped mesoporous titania (1:2). Photocatalysts reduce the MO dye into derivative of hydrazine. Photoactivity of N-doped mesoporous titania (1:2) is 1.0721 mg of MO reduced per g of TiO 2 vis-à-vis 0.508 mg of MO reduced per g of TiO 2 for Degussa P25 photocatalyst. The effect of various operating parameters like photocatalyst loading, initial concentration and intensity of light also has been studied.