Boosting Photocatalytic N2 Fixation on N‐Defect g‐C3N4/WO3: the Synergistic Effects of Nitrogen Vacancy and Z‐Scheme Heterojunction

Abstract Photocatalytic nitrogen fixation is a promising strategy for ammonia synthesis under mild conditions by using solar energy, but N2 activation remains a great challenge. Herein, we demonstrate that a Z‐scheme g‐C3N4/WO3 heterojunction possessing abundant nitrogen vacancies exhibits the highly enhanced activity for photocatalytic N2 fixation through efficient nitrogen molecular activation compared with pristine NVs‐g‐C3N4 and WO3 photocatalysts. The construction of the internal electric field induced by Z‐scheme NVs‐g‐C3N4/WO3 heterojunction allows a rapid charge carrier separation and simultaneously maintains the powerful redox ability of photogenerated charge carriers, defined by the covalent CO bond. Moreover, nitrogen vacancy plays a crucial role in the adsorption/activation of N2, which substantially facilitates the hydrogenation to generate NH3. According to experimental and theoretical investigations, photocatalytic N2 fixation on NVs‐g‐C3N4/WO3 composites is proposed to be energetically favorable in the alternating pathway. This study offers an alternative way for the design of efficient photocatalysts for photocatalytic N2 fixation.