In Situ Fabrication of 3D Octahedral g-C3N4/BiFeWOx Double-Heterojunction for Highly Selective CO2 Photoreduction to CO Under Visible Light

A series of g-C3N4/BiFeWOx composites (GN-x/BFW) with double-heterojunction composites as photocatalysts for efficient and stable CO2 photoreduction had been rationally designed and synthesized by the facile insitu hydrothermal method. In situ growing BFW on g-C3N4 sheets achieved that the g-C3N4 was embedded in the inner of BFW as well as wrapped on the surfaces of BFW. The obtained heterojunction composites greatly inhibited the recommendation of photogenerated electron/hole pairs and enhanced the light respond on the visible light due to the tight chemically bonded interface interaction. Benefiting from the unique structure, the optimized GN-5.0%/BFW heterostructure catalyst showed a higher performance of photoreduction CO2 to CO (43molh(-1)g(-1)) than that of pure BFW (5.2molh(-1)g(-1)) and g-C3N4 (8.9molh(-1)g(-1)) under visible light irradiation at 10 degrees C. Besides, the GN-x/BFW composites exhibited outstanding recycling photostability and structural stability. A possible Z-scheme mechanism was proposed according to the staggered band potentials between g-C3N4 and BFW and ESR results. Similarly, this facile synthetic method could be employed to fabricate other composites to accelerate the photocatalytic performance.