Synthesis of Mn-sensitized TiO2nanoparticles: influence of sequence of reagents on phase composition and photocatalytic activity

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 17; no. 10
• Main Authors: Kuzmicheva, Galina M., Savinkina, Elena V., Obolenskaya, Lubov N., Zubavichus, Yan V., Murzin, Vadim Y., Podbelskiy, Vadim V., Sadovskaya, Nataliya V.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 2015
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Inorganic Chemistry; Lasers; Materials Science; Nanotechnology; Optical Devices; Optics; Photonics; Physical Chemistry; Research Paper; Photocatalysis; Sensitization; Titania; Nanostructured materials; Manganese
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-015-3211-2

A new approach has been developed to synthesize manganese-containing titanium dioxide materials by hydrolysis of titanyl sulfate. The samples were studied by a complex of methods (synchrotron radiation X-ray powder diffraction, high-resolution scanning electron microscopy with energy-dispersive X-ray spectroscopy, absorption spectroscopy). The sequence of the added reagents effects the phase composition (anatase or mixtures of anatase and “ η -TiO 2 ”), size of crystallites, nanoparticles and agglomerates, manganese content, and oxidation state (Mn 3+ , Mn 2+ /Mn 3+ , or Mn 3+ /Mn 4+ ). The Mn-doped TiO 2 samples have been proven to have high photocatalytic activity for methyl orange (MO) under visible light. The rate of MO degradation reached 0.0046 min −1 (50 % in 150 min) for the sample containing a mixture of anatase (75 %) and “ η -TiO 2 ” (25 %) with a high degree of amorphism; the sample is characterized by the smallest size of crystallites (44.3 Å), the largest size of nanoparticles (33 nm) and agglomerates (10 μm), and the lowest manganese content (0.3 at. %) with the ratio Mn 3+ :Mn 4+  = 1:1. The resultant Mn-doped titania has potential applications in photocatalysis and environmental protection. Graphical Abstract