Facile fabrication of SnO2 modified hierarchical BiOI S-scheme heterojunction photocatalyst with efficient activity for carbon dioxide reduction.

[Display omitted] The use of photocatalysts on semiconductor substrates is a promising strategy for multiple use of solar energy and environmental improvement to convert CO 2 to CH 3 OH. In this paper, a series of SnO 2 -modified BiOI (SnO 2 /BiOI) novel s-scheme heterojunction microsphere catalysts were synthesized, and the effect of temperature on the photocatalytic CO 2 reduction reactivity of SnO 2 grown on pure BiOI surface was systematically investigated by adjusting the calcination reaction temperature. Among all SnO 2 /BiOI composite photocatalytic systems, the highest CH 3 OH yield (1183 μmol/g cat , 4 h) was achieved when SnO 2 /BiOI was synthesized at 400 °C, which was 2.7 times higher than that of BiOI alone (437 μmol/g cat, 4 h). The SnO 2 /BiOI microspheres with s-scheme heterojunction exhibited surprising photocatalytic performance for CH 3 OH formation due to the formation of an internal eletricfield between SnO 2 and BiOI also facilitated the separation of the photogenerated electron-hole pairs. [ABSTRACT FROM AUTHOR]