One-pot solvothermal synthesis of flower-like Fe-doped In2S3/Fe3S4 S-scheme hetero-microspheres with enhanced interfacial electric field and boosted visible-light-driven CO2 reduction.

An efficient S-scheme photocatalyst based on 3D flower-like Fe-doped In 2 S 3 /Fe 3 S 4 hetero-microspheres assembled from interconnected nanosheets was synthesized via a facile one-pot solvothermal reaction, which exhibits the enhanced interfacial electric field and boosted visible-light-driven CO 2 reduction. [Display omitted] S-scheme heterojunctions hold great potential for CO 2 photoreduction into solar fuels, but their activities are severely limited by the low efficiency of interfacial charge transfer. In this work, a facile one-pot solvothermal reaction has been developed to dope Fe into flower-like In 2 S 3 /Fe 3 S 4 hetero-microspheres (Fe-In 2 S 3 /Fe 3 S 4 HMSs), which are demonstrated as an efficient S-scheme photocatalyst for visible-light-driven CO 2 photoreduction. The doping of Fe not only reduces the bandgap of In 2 S 3 and thus extends the optical response to the visible-light region, but also increases the densities of donors and sulfur vacancies, which leads to an elevated Fermi level (E f). The difference of E f between In 2 S 3 and Fe 3 S 4 is enlarged and their band bending at the interface is therefore enhanced, which results in promoted carriers transfer in the S-scheme pathway due to the reinforced interfacial electric field. Moreover, Fe-doped In 2 S 3 reduces the formation energy of the *CO intermediate, which thermodynamically favors the CO evolution at the surface. As a result, the Fe-In 2 S 3 /Fe 3 S 4 HMSs exhibit a significantly boosted CO 2 photoreduction activity in comparison with bare In 2 S 3 and Fe-In 2 S 3 samples. This work demonstrates the great potential of heteroatom-engineered S-scheme photocatalysts for CO 2 photoreduction. [ABSTRACT FROM AUTHOR]