Constructing asymmetric active sites on defective Ru/W18O49 for photocatalytic nitrogen fixation. Issue 3 (3rd January 2023) - Shang, Huan
Abstract : Boosting photocatalytic N2 fixation can be achieved on Ru/W18 O49 by tuning defect states by constructing asymmetric active sites. Abstract : Defect engineering can offer active sites for N2 adsorption and activation due to the abundant localized electrons of surface defects. However, the high energy barriers of the defect band can restrict the electron transfer, which thus limits the photocatalytic N2 fixation performance. Herein, we demonstrate that Ru/W18 O49 exhibits a nearly 6-fold enhanced photocatalytic activity for ammonia production under visible irradiation compared with pristine W18 O49 . Our investigations reveal that the enhanced photocatalytic N2 fixation activities are mainly attributed to the synergistic effect of oxygen vacancies and Ru modification. The decorated Ru species can modify the coordination structure of oxygen vacancies by forming Ru–O–W bonds. The Ru–O–W centers can serve as active sites for the side-on adsorption of N2 due to their asymmetric polarization, better promoting the electron transfer to absorbed N2 . Moreover, the LSPR between Ru and oxygen vacancies provides sufficient electrons for N2 activation. As a result, the efficient electron transfer facilitates the activation and dissociation of N2 on Ru/W18 O49, which is feasible for the reduction of N2 to NH3 . This work provides a promising strategy for enhanced photocatalytic N2 fixation by modulating defect engineering.