Ultrafast electron transfer at the In2O3/Nb2O5 S-scheme interface for CO2 photoreduction

Abstract

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, In₂O₃/Nb₂O₅ 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 Nb₂O₅ conduction band and In₂O₃ valence band, respectively, exhibiting extended long lifetimes and facilitating their involvement in subsequent photoreactions. Combined with the efficient chemisorption and activation of stable CO₂ on the Nb₂O₅, the resulting In₂O₃/Nb₂O₅ hybrid nanofibers demonstrate improved photocatalytic performance for CO₂ conversion.