fig9

Figure 9. Strain engineering on photocatalysis and its mechanism analysis. (A) Proposed mechanism for photocatalytic CO₂ reduction using lattice-strain optimized Ni(OH)₂ nanosheets; (B) and (C) CO₂-TPD and PL spectra plots of Ni(OH)₂ nanosheets and 10% V-doped Ni(OH)₂ nanosheets; (D) The gas production yield and CO selectivity of x% V-Ni(OH)₂ nanosheets were evaluated under a pure CO₂ atmosphere; (E) CO₂ photo reduction performances of 10% V-Ni(OH)₂ nanosheets and Ni(OH)₂ were evaluated under varying CO₂ concentrations within the first hour; (F) Comparison of Ni K-edgeXANES spectra of 10% V-Ni(OH)₂ nanosheets before and after the reaction; (A-F): quoted with permission from Liang et al.^[67]; (G) Schematic photocatalytic process of N₂ fixation on the surface of ultrathin TiO₂ nanosheets with V_O and engineered strain; (H) UV-vis diffuse reflectance spectra for Bulk-TiO₂ and the x%-TiO₂ nanosheets (contain x% mol Cu); (I) Yield of NH₃ of different samples after UV-vis illumination for 1h with water as the proton source; (J) The calculated adsorption energies of N₂ on TiO₂-Pure, TiO₂-V_O, and TiO₂-V_O-Strain; (K) N-N distance of N₂ on TiO₂-Pure, TiO₂-V_O, TiO₂-V_O-Strain, N₂H₂, and N₂H₄; (L) The free energy diagram depicting the N₂ fixation process on the surface of TiO₂-Pure, TiO₂-V_O, and TiO₂-V_O-strain; (G-L): quoted with permission from Zhao et al.^[72]. PL: Photoluminescence; TPD: temperature programmed desorption; XANES: X-ray absorption near edge structure; UV-vis: ultraviolet-visible.