Enhanced photocatalytic NH3 synthesis for Bi2MoO6 regulated by doping of fluorine and iodine

This study presents a novel fluorine and iodine co-doped Bi2MoO6 (Bi2MoO6–F–I) photocatalyst prepared using a solvothermal method. The photocatalytic performance of Bi2MoO6–F–I in N2 photocatalytic reduction to NH3 is considerably enhanced compared to that of pristine Bi2MoO6. The experimental findings and theoretical calculations reveal that F− substitute lattice O2− in Bi2MoO6, creating a -Mo-F-Mo- configuration, while I− modifies the surface, forming -Bi-I species in Bi2MoO6–F–I, which serve as high-adsorption centres and active surface sites, facilitating N2 and H2O molecule adsorption and activation on the surface. The synergistic effect of F− doping and -Bi-I surface species optimizes the band structure of Bi2MoO6–F–I, aligning more effectively with the redox potential of N2 photoreduction, which consequently promotes photogenerated carrier separation and redox capability. The remarkable improvement in the photocatalytic performance of Bi2MoO6–F–I in N2 photoreduction to NH3 lays foundation for designing and fabricating high-performance Bi2MoO6-based photocatalysts.