Spatial Separation of Charge Carriers in In2O3–x(OH)y Nanocrystal Superstructures for Enhanced Gas-Phase Photocatalytic Activity

The development of strategies for increasing the lifetime of photoexcited charge carriers in nanostructured metal oxide semiconductors is important for enhancing their photocatalytic activity. Intensive efforts have been made in tailoring the properties of the nanostructured photocatalysts through different ways, mainly including band-structure engineering, doping, catalyst–support interaction, and loading cocatalysts. In liquid-phase photocatalytic dye degradation and water splitting, it was recently found that nanocrystal superstructure based semiconductors exhibited improved spatial separation of photoexcited charge carriers and enhanced photocatalytic performance. Nevertheless, it remains unknown whether this strategy is applicable in gas-phase photocatalysis. Using porous indium oxide nanorods in catalyzing the reverse water–gas shift reaction as a model system, we demonstrate here that assembling semiconductor nanocrystals into superstructures can also promote gas-phase photocatalytic processes. Tra...