RESEARCH / A0425
Tuning Oxygen Vacancies by Construction of a SiO2@TiO2 Core−Shell Composite Structure for Boosting Photocatalytic CO2 Reduction Towards CH4
Read the original paper · 10.1002/cey2.700 ↗
Source figures may contain other techniques and soft X-ray spectra. C, N and O measurements are outside our current hard-XAFS testing range.
FIGURE 2 | High‐resolution XPS (A) Ti 2p, (B) Si 2p, and (C) O 1s spectra of the samples. (D) Ti K‐edge XANES spectra. The inset shows magnification of the labeled region. (E) Corresponding k2‐weighted FT‐EXAFS spectra of the Ti foil, TiO2, and SiO2@TiO2‐X (X = 25, 50, 100, and 200). (F) Correlation of oxygen vacancy concentration and CN of the Ti–O shell with the Si/Ti ratio in TiO2 and SiO2@TiO2‐X (X = 25, 50, 100, and 200). (G) EPR spectra of TiO2 and SiO2@TiO2‐X (X = 25, 50, 100, and 200). (H) Optimized structural model of SiO2@TiO2‐X. (I) Comparison of the calculated oxygen vacancy formation energy for TiO2 and SiO2@TiO2.