Sn modification of TiO2 anatase and rutile type phases: 2-Propanol photo-oxidation under UV and visible light

Homojunction and defect synergy-mediated electron–hole separation for solar-driven mesoporous rutile/anatase TiO2 microsphere photocatalysts

“…The peaks at 143, 437 and 610 cm À1 can be assigned to the classical vibrational of B 1g , E g and A 1g , which are characteristic of the rutile phase. 33,35,36 In addition, the peak at 238 cm À1 is caused by the multi-proton scattering process. It is worth pointing out that the Raman peaks at 513 cm À1 can be attributed to the typical anatase bands of A 1g (B 1g ), further conrming that the mesoporous TiO 2 microspheres are comprised of the rutile/ anatase phase.…”

FeOx Derived from an Iron-Containing Polyoxometalate Boosting the Photocatalytic Water Oxidation Activity of Ti3+-Doped TiO2

“…After photodeposition, Ti 2p of F/Ti 3+ /TiO 2 does not show obvious changes compared with Ti 3+ /TiO 2 . The presence of FeO x is verified by an XPS plot of Fe 2p (Figure b).The high-resolution XPS spectrum of Fe 2p shows two peaks at 712 and 725 eV, which are assigned to Fe 2p 3/2 and Fe 2p 1/2 of Fe 3+ . , The peak position of O 1s shifts from 529.6 eV in Ti 3+ /TiO 2 to 530.7 eV in F/Ti 3+ /TiO 2 (Figure S8), which may be affected by the coating layer outside the Ti 3+ /TiO 2 nanorod. , After the photodeposition process, the Sb 3d and W 4f spectra of F/Ti 3+ /TiO 2 were detected and are shown in Figures S9 and S10. The valence state of Sb and W are confirmed as +3 and +6 according to the peak position. , Because of the overlapping of the Sb 3d and the O 1s core peak, the valence state of Sb is confirmed as +3 according to the peak at 539.2 eV …”

Role of Synthetic Parameters on the Structural and Optical Properties of N,Sn-Copromoted Nanostructured TiO2: A Combined Ti K-Edge and Sn L2,3-Edges X-ray Absorption Investigation

“…The promotion of TiO 2 photocatalysts with Sn species, either by doping with Sn ions or by composite formation with SnO x , has been successfully applied to numerous fields, such as the photocatalytic degradation of water [ 1 , 2 ] and air pollutants [ 3 , 4 , 5 ], photovoltaics [ 6 ], and hydrogen production [ 7 , 8 ]. Because one of the main disadvantages of TiO 2 photocatalysts is their limited activity in the visible region, due to the large band gap (≥3.0 eV) [ 9 ], doping with Sn 2+ species has raised interest as a strategy for promoting TiO 2 visible light activity [ 1 , 2 , 3 , 5 , 8 ].…”

“…Doping with Sn 4+ has been reported to be beneficial to TiO 2 activity, but only under UV irradiation [ 4 ]. Indeed, DFT calculations [ 11 , 12 ] have shown no effect or a blue shift in the absorption edge of anatase and rutile TiO 2 when Sn 4+ substitutional doping occurs; the latter has been reported to be the most energetically favored situation at low dopant content [ 11 , 12 , 13 ].…”

“…Indeed, DFT calculations [ 11 , 12 ] have shown no effect or a blue shift in the absorption edge of anatase and rutile TiO 2 when Sn 4+ substitutional doping occurs; the latter has been reported to be the most energetically favored situation at low dopant content [ 11 , 12 , 13 ]. Conversely, the surface segregation of SnO x clusters has been often observed at higher Sn content [ 4 , 13 , 14 ]. The formation of heterojunctions with SnO 2 , while beneficial for the charge separation of photogenerated carriers [ 15 , 16 ], does not promote visible light activity of the resulting composite due to the large band gap of SnO 2 [ 17 ].…”