Отримання та характеризація діоксиду титану, модифікованого вуглецем, з підвищеною фотокаталітичною активністю

• Date: 2016
• Main Authors: Bondarenko, M. V., Khalyavka, T. A., Camyshan, S. V., Petrik, I. S.
• Format: Article
• Language: English
• Published: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2016
• Subjects: діоксид титану; вуглець; cафранін Т; фотокаталіз
• Online Access: https://www.cpts.com.ua/index.php/cpts/article/view/403
• Journal Title: Chemistry, Physics and Technology of Surface

The aim of our work was to prepare nanoscale composites based on TiO2 and carbon photocatalytically active under UV and visible irradiation in the destruction of safranin T. The samples were characterized by XRD, BET, SEM, UV-Vis and IR spectroscopy. X-ray analysis revealed photocatalytically active phase of anatase in all the composites. The powders consist of roundish agglomerates, crystallite size in agglomerates is 15 nm. Analysis of nitrogen sorption–desorption isotherms for the samples show the presence of a hysteresis loop which is the evidence for mesoporous structure. Vibrational spectra of the composites reveal the following bands: near 700 cm?1 corresponding to the Ti–O stretching vibration; around 3407 cm–1 attributed to the surface-adsorbed H2O; at 1628 cm–1 which is referred to deformational vibrations in adsorbed water, and around 1300–1500 cm–1 corresponding to carbon–oxygen bonds. Absorption spectra of nanocomposites show a bathochromic shift as compared with those of TiO2. Modification of TiO2 with carbon leads to band gap narrowing of composites, as well as to emerging of additional energy levels in the band gap of TiO2 with energies of 3.12–3.14 eV under valence band; that leads to sensitizing of C/TiO2 composites to visible irradiation. Nanocomposites show higher photocatalytic activity compared to pure TiO2. It may be connected with the participation of carbon in the inhibition of electron–hole recombination, prolongation of charge lifetime, increasing of efficiency of interfacial charge separation from TiO2 to carbon and formation of doping electronic states inside the TiO2 band gap.