Synergistic Effects of Sm and C Co-Doped Mixed Phase Crystalline TiO2 for Visible Light Photocatalytic Activity

Abstract

Mixed phase TiO2 nanoparticles with element doping by Sm and C were prepared via a facile sol-gel procedure. The UV-Vis light-diffuse reflectance spectroscopy analysis showed that the absorption region of co-doped TiO2 was shifted to the visible-light region, which was attributed to incorporation of samarium and carbon into the TiO2 lattice during high-temperature reaction. Samarium effectively decreased the anatase-rutile phase transformation. The grain size can be controlled by Sm doping to achieve a large specific surface area useful for the enhancement of photocatalytic activity. The photocatalytic activities under visible light irradiation were evaluated by photocatalytic degradation of methylene blue (MB). The degradation rate of MB over the Sm-C co-doped TiO2 sample was the best. Additionally, first-order apparent rate constants increased by about 4.3 times compared to that of commercial Degusssa P25 under the same experimental conditions. Using different types of scavengers, the results indicated that the electrons, holes, and •OH radicals are the main active species for the MB degradation. The high visible-light photocatalytic activity was attributed to low recombination of the photo-generated electrons and holes which originated from the synergistic effect of the co-doped ions and the heterostructure.

Facile Formation of Anatase/Rutile TiO2 Nanocomposites with Enhanced Photocatalytic Activity

“…Recently, Honget al prepared the Fe 3 O 4 /TiO 2 nanocomposites by using ilmenite as a raw material under solvothermal conditions, which showed higher photocatalytic activity conversion of Rhodamine B into degraded or mineralized products than the best commercially available P25-TiO 2 nanoparticles [14]. Peng et al prepared crystalline anatase/rutile mixed phase Sm-C-TiO 2 catalysts by an ordinary sol-gel method, which showed better photocatalytic activity than undoped TiO 2 and the commercial Degussa P25-TiO 2 for the photocatalytic degradation of methylene blue [15]. Atitar et al prepared the mesoporous anatase–rutile TiO 2 mixtures through a simple one step sol-gel process at different temperatures, which showed higher activity for the decomposition of both imazapyr and phenol, compared to the nonporous P25-TiO 2 [16].…”

Facile Synthesis of “Boron-Doped” Carbon Dots and Their Application in Visible-Light-Driven Photocatalytic Degradation of Organic Dyes

“…There are mainly two reasons to select these two dyes. First, the degradation of these two dyes has been widely used as model reactions to probe the photocatalytic ability of various materials including metal and oxide nanoparticles, quantum dots, and carbon-based nanomaterials [88][89][90]. Second, these two dyes are both positively charged, while our C-dots have a negative zeta potential (−11.6).…”

Synthesis, characterisation and investigation of enhanced photocatalytic activity of Sm<SUP align="right">+3</SUP>, Ni<SUP align="right">+2</SUP> co-doped TiO<SUB align="right">2 nanoparticles on the degradation of azo dyes in visible region

“…The intensity of peak at 1,636 cm -1 decreases with the increased in metal contents (Lin et al, 2006;Štengl et al, 2009). The appearance of peaks at 1,168 cm -1 is due to the Sm-O-Ti vibrations (Xu et al, 2002;Peng et al, 2017), and change in the intensity of this peak is attributed to the change in particle size of TiO 2 nanoparticles with different doping content of metals. These results are in accordance with the already reported literature for doped TiO 2 47,55-63 .…”