In Situ-Fabricated 2D/2D Heterojunctions of Ultrathin SiC/Reduced Graphene Oxide Nanosheets for Efficient CO Photoreduction with High CH Selectivity.

Photoreduction of CO into fuel molecules such as CH represents a promising route to simultaneously explore renewable energy and alleviate global warming. However, the implementation of such a process is hampered by low product yields and poor selectivity. A 2D/2D heterojunction of ultrathin SiC and reduced graphene oxide (RGO) nanosheets was fabricated in situ for efficient and selective photoreduction of CO . Ultrathin SiC suppresses significant charge recombination in the bulk phase, thus providing more energetic electrons. The robust 2D/2D heterojunction allows fast transfer of energetic electrons from SiC to RGO. Combining the vital role of RGO in facilitating CO activation, the optimized SiC/RGO exhibits an electron-transfer rate of 58.17 μmol h  g towards CO reduction, 2.7 times that of pure SiC (20.25 μmol h  g ). About 92 % of the transferred electrons from SiC are devoted to generating CH (6.72 μmol h  g ). Such high efficiency and selectivity are mainly a result of the densely accumulated energetic electrons within RGO, which facilitate the eight-electron process to produce CH . This work will inspire the design of catalyst/cocatalyst systems for efficient and selective photoreduction of CO .