Interfacial Mo-S bond-reinforced hierarchical S-scheme heterostructure of Bi2MoO6@ZnIn2S4 for highly-selective and efficient CO2 photoreduction into CO.

• An interfacial Mo-S bond-bridged hierarchical S-scheme heterostructure is reported. • The Mo-S bonds can reinforce the separation and migration of photoinduced carriers. • The hierarchical heterostructure can benefit the CO 2 adsorption and activation. Developing highly-selective and efficient photocatalysts for converting CO 2 into carbon-based fuels by solar energy is desirable, whereas it is still a severe challenge. Herein, we present a unique interfacial Mo-S bond-bridged hierarchical S-scheme heterostructured photocatalysts, prepared by in-situ loading ZnIn 2 S 4 nanoflakes (ZIS-NFs) on the Bi 2 MoO 6 porous micro-spheres (BMO-PMs) assembled from numerous nanosheets. The interfacial Mo-S bonds can reinforce the separation and migration of photoinduced charge carriers via the S-scheme mechanism in the BMO@ZIS heterostructure. Besides, its hierarchical heterostructure can improve the visible-light response ability, and afford plenty of active sites so as to benefit the CO 2 adsorption and activation. Specifically, the combined results of experiment and density functional theory (DFT) calculations indicate that the fine heterostructure can not only convert the endoergic rate-determining step of bare ZIS (namely, CO 2 * hydrogenation to form COOH*) to an exoergic reaction process and lower the overall activation energy barrier, but also boost the desorption of CO* from the ZIS surface. As a result, in existence of H 2 O vapor without any sacrificial agents, the optimum photocatalyst (BMO@ZIS-0.4) manifests the outstanding CO 2 photoreduction activity, with a CO yield and selectivity of 23.11 μmol g−1h−1 and 93.1 %, respectively, higher than those of the most reported photocatalysts. This work offers an in-depth insight for fabricating the interfacial chemical bond-modulated hierarchical S-scheme heterostructure with a remarkable performance of CO 2 conversion. [ABSTRACT FROM AUTHOR]