Design of sculptured SnS/g-C3N4 photocatalytic nanostructure for highly efficient and selective CO2 conversion to methane

Here, we demonstrate the SnS/g-C3N4 crystallized and nanostructured photocatalysts for efficient and selective CO2 conversion to CH4 by engineered thermal evaporation and the decoration of g-C3N4 through a simple dipping method, overcoming the limitation of bulk SnS-based photocatalysts. The SnS/g-C3N4 nanostructured photocatalysts exhibit a superior methane production rate of 387.5 μmol∙m−2∙h−1 (= c.a. 122.33 μmol∙g−1∙h−1) with an apparent quantum yield of c.a. 9.7% at 520 nm with engineered lengths. Moreover, 100% selective production toward CH4 is also measured from the SnS/g-C3N4 photocatalysts, with > 10 h stable operation. These performances are, to the best of our knowledge, the highest production rate among reported photocatalytic films and metal sulfide/g-C3N4 composite-based photocatalysts. These highly improved performances are attributed to synergistic effects by the formation of nanostructured SnS/g-C3N4, exhibiting superior light absorption, higher crystallinity, Z-scheme charge transport via C-S bonding, physical advantages of the SnS nanostructure, and excellent physiochemical properties of the surfaces.