Synthesis and Characterization of Mn-C-Codoped TiO_2 Nanoparticles and Photocatalytic Degradation of Methyl Orange Dye under Sunlight Irradiation

摘要

Novel visible-light-active Mn-C-TiO_2 nanoparticles were synthesized by modified sol-gel method based on the self-assembly technique using polyoxyethylenes orbitan monooleate (Tween 80) as template and carbon precursor and manganese acetate as manganese precursor. The samples were characterized by XRD, FTIR, UV-vis diffuse reflectance, XPS, and laser particle size analysis. The XRD results showed that Mn-C-TiO_2 sample exhibited anatase phase and no other crystal phase was identified. High specific surface area, small crystallite size, and small particle size distribution could be obtained by manganese and carbon codoped and Mn-C-TiO_2 exhibited greater red shift in absorption edge of samples in visible region than that of C-TiO_2 and pure TiO_2. The photocatalytic activity of synthesized catalyst was evaluated by photocatalytic oxidation of methyl orange (MO) solution under the sunlight irradiation. The results showed that Mn-C-TiO_2 nanoparticles have higher activity than other samples under sunlight, which could be attributed to the high specific surface area, smaller particle size, and lower band gap energy.