Performance of Magnéli phase Ti4O7 and Ti3+ self-doped TiO2 as oxygen vacancy-rich titanium oxide anodes: Comparison in terms of treatment efficiency, anodic degradative pathways, and long-term stability

Novel double-layer core–shell photocatalyst CdS–TiO2@NH2-MIL-101: enhanced conversion of CO2 and CH4 at ambient temperature

“…4c), which were related to the spin–orbit splitting photoelectronic activity of the Ti 2p 1/2 and Ti 2p 3/2 chemical states of Ti 4+ . 54–56 However, the peak of the characteristic energy spectrum of CdS–TiO 2 @NH 2 -MIL-101 showed a slight shift to the right, which may be related to the interaction of Cd with the NH 2 group.…”

CdS/ZnSnO3 Hollow Core–Shell Nanocubes for Photocatalytic Hydrogen Evolution and Degradation of Ciprofloxacin

“…For ZSO, owing to the wide optical band gap, it exhibits only ultraviolet light response and the corresponding optical band gap is 3.973 eV (Figure S9a,b). − With Sn 2+ self-doping, owing to its stable crystalline structure and shallow donor level, the optical band gap of Sn 2+ -ZSO decreases to 3.872 eV. − Significantly, the increased photocatalytic performance is much higher than the increased light response, including the HER and CIP degradation, indicating that the carrier behavior regulation caused by the shallow donor level and complex electronic structure of O v would play more important roles. − With deposition of CdS, the absorption edge exhibits a remarkable red shift and the corresponding optical band gap of CdS/Sn 2+ -ZSO (CdS/Sn 2+ -ZSO-3) is 2.767 eV, which is the median of CdS (the optical band gap of CdS is 2.332 eV) and Sn 2+ -ZSO. − Similarly, the increased photocatalytic performance is much higher than the increased visible-light response, indicating that the carrier behavior regulation caused by the heterojunction would be the decisive factor instead of the simply increased absorption.…”

“…As revealed, the diffraction peaks at 33.98 and 59.36°are ascribed to the (100) and (120) planes of ZnSnO 3 (PDF#89-0095, Figure S1), 12−16 and are consistent with the samples with Sn 2+ self-doping and CdS deposition, indicating that the Sn 2+ ion self-doping would hardly influence the crystalline structure and the ZnSnO 3 owing to its decent stability during the surface heterojunction deposition. 12,31,32 With deposition of the CdS nanoshell, the new diffraction peaks at 25.45, 26.90, 28.34, 44.12, and 52.36°are ascribed to the (100), ( 002), ( 101), (110), and (112) planes of CdS (PDF#41-1049). 37−42 Interestingly, all diffraction peaks exhibit obvious broadening, which can be ascribed to the minuscule grain size of the CdS nanoshell.…”

“…30 For example, Ti 3+ /Ti 4+ ions in mixed state in TiO 2 can form a new electronic energy level to narrow the band gap; at the same time, the concomitant O v can act as an electron-trapping center to effectively adsorb the excited electrons and slow down the carrier recombination. 31,32 Zhao et al used anodic oxidation to prepare the Ti 3+ /TiO 2 thin films on a Ti foil substrate and realize a high efficiency of photodegradation. 33 Such variable-valence metal cation selfdoping can also be used in other systems, including metallic oxides or metal ions of B in ABO 3 -type perovskites.…”

“…Among these, the metal cation self-doping strategy has generated great interest; besides the mentioned advantages, it can adjust the surface properties and electronic structure with minimal lattice distortion to maintain the crystal stability. , In addition, the metal cations with different chemical valences can induce the formation of numerous charge carriers, and the concomitant oxygen vacancy (O v ) can induce a shallow donor level for improve the solar efficiency . For example, Ti 3+ /Ti 4+ ions in mixed state in TiO 2 can form a new electronic energy level to narrow the band gap; at the same time, the concomitant O v can act as an electron-trapping center to effectively adsorb the excited electrons and slow down the carrier recombination. , Zhao et al used anodic oxidation to prepare the Ti 3+ /TiO 2 thin films on a Ti foil substrate and realize a high efficiency of photodegradation . Such variable-valence metal cation self-doping can also be used in other systems, including metallic oxides or metal ions of B in ABO 3 -type perovskites .…”