Construction of octahedral BiFeWOx encapsulated in hierarchical In2S3 core@shell heterostructure for visible-light-driven CO2 reduction

Novel 3D BiFeWOx@In2S3 (BFW@IS-x) core shell heterostructures were rationally designed and fabricated to be used as efficient photocatalysts for CO2 photoreduction. The constructive strategy integrated nano-octahedral BFW and hierarchical IS by growing IS ultrathin nanosheet subunits on surface of BFW. The proposed in site synthesis route resulted in a high dispersion of BFW nanocrystals and the tight interaction between BFW and IS. The obtained core-shell heterostructure boosted separation and transfer of photoinduced charge carriers, evidenced by electrochemical measurement. The hierarchical structure on the surface of BFW@IS-x catalyst enhanced light harvest and provided ample active sites for surface redox reactions. Profiting from these extraordinary chemical and physical characteristics owing to the interaction between BFW and IS, the efficiency of photo-conversion of CO2 to CH4 and CO over BFW@IS-1 heterostructures with optimal proportion was 49.9 mu mol h(-1) g(-1) and 28.9 mu mol h(-1) g(-1), respectively, under visible light irradiation. The CH4 generated rate was about 3.5 and 6.4 times higher than that of pure IS and BFW, and CO generated rates was 4.9 times higher than that of pure IS, respectively. The possible mechanism for the CO2 reduction over BFW@IS-1 composite was discussed.