Efficient charge transfer and CO2 photoreduction of hierarchical CeO2@SnS2 heterostructured hollow spheres with spatially separated active sites

Abstract

Heterostructured hybrids with hollow configuration and efficient charge separation are very promising for CO2 photoreduction. This study demonstrates the design and fabrication of hierarchical double-shelled CeO2@SnS2 hollow spheres with spatially separated active sites (MnOx/CeO2@SnS2/Ni2P DSHSs) for efficient CO2 photoreduction. In this catalyst system, MnOx and Ni2P cocatalysts are selectively anchored on the CeO2 and SnS2 shells, respectively, forming spatially separated active sites. The confinement effect of outer-surface SnS2 nanosheets offers more opportunities for Ni2P cocatalyst to react with CO2 molecules. Owing to the desired hierarchical double-shelled hollow architecture and spatially-separated cocatalysts, the MnOx/CeO2@SnS2/Ni2P DSHSs possess the advantages of abundant spatially-separated active sites, enhanced visible-light harvesting, and accelerated charge separation. As expected, the optimized MnOx/CeO2@SnS2/Ni2P DSHSs sample exhibits remarkable CO2 photoreduction activity. The CO yield and selectivity reach 29.67 μmol g−1 h−1 and 90.1%, respectively, which are remarkably higher than the control samples. This study demonstrates a promising strategy to construct well-defined hierarchical hybrid catalysts for maximizing CO2 photoreduction performance.