Ultrafast electron transfer at the InO/NbO S-scheme interface for CO photoreduction.

Constructing S-scheme heterojunctions proves proficient in achieving the spatial separation of potent photogenerated charge carriers for their participation in photoreactions. Nonetheless, the restricted contact areas between two phases within S-scheme heterostructures lead to inefficient interfacial charge transport, resulting in low photocatalytic efficiency from a kinetic perspective. Here, InO/NbO S-scheme heterojunctions are fabricated through a straightforward one-step electrospinning technique, enabling intimate contact between the two phases and thereby fostering ultrafast interfacial electron transfer (<10 ps), as analyzed via femtosecond transient absorption spectroscopy. As a result, powerful photo-electrons and holes accumulate in the NbO conduction band and InO valence band, respectively, exhibiting extended long lifetimes and facilitating their involvement in subsequent photoreactions. Combined with the efficient chemisorption and activation of stable CO on the NbO, the resulting InO/NbO hybrid nanofibers demonstrate improved photocatalytic performance for CO conversion.