Internal Electric Field-Driven Dynamic Electron Shuttling at Asymmetric Ti–O–W Active Sites for Selective Photocatalytic CO2 Reduction into C2H4

The efficiency of electron utilization and C–C coupling is crucial to the selectivity of photocatalytic CO2 reduction to multicarbon (C2+) hydrocarbon products. Herein, the multifunctional catalyst of TiO2-modified W18O49 nanospheres (TimWOx) was successfully fabricated by in situ growth hydrothermal method. The distinct interfacial energy between W18O49 and TiO2 can promote the charge redistribution at the asymmetric Ti–O–W active sites and facilitate the formation of an internal electric field (IEF). Photogenerated electrons driven by the IEF can improve the dynamic electron shuttling between Ti and W centers for enhancing electron utilization efficiency during CO2 photoreduction. TimWOx catalysts exhibit high activity for photocatalytic CO2 reduction to C2+ products, i.e., the yield and selectivity of C2H4 over Ti0.25WOx are 46.3 μmol·g–1 and 72.01%, respectively, which is 7.25 times that of pristine W18O49. Combined with the results of in situ diffuse reflectance infrared Fourier transform spectra and DFT calculations, the photocatalytic mechanism is proposed: the protonation the *OCCOH intermediate is key step for selective photocatalytic CO2 reduction into C2H4, and the energy barrier for the protonation of the *OCCOH intermediate is lowered by IEF-induced dynamic electron shuttling, which selectively steers the reaction pathway toward C2H4 formation. This work highlights the role of interfacial electric fields in guiding electron shuttling for selective photocatalytic C–C coupling, which benefits developing highly efficient photocatalysts.