The study investigates the construction of an S-scheme heterojunction between In₂O₃ and Nb₂O₅ to enhance the photocatalytic reduction of CO₂. The heterojunction is fabricated using a one-step electrospinning technique, ensuring intimate contact between the two phases and promoting ultrafast electron transfer (<10 ps) as confirmed by femtosecond transient absorption spectroscopy. This results in the accumulation of powerful photoelectrons in the Nb₂O₅ conduction band and photoholes in the In₂O₃ valence band, extending their lifetimes and facilitating their involvement in subsequent photoreactions. The chemisorption and activation of CO₂ on Nb₂O₅ further enhance the photocatalytic performance of the In₂O₃/Nb₂O₅ hybrid nanofibers. The optimized heterojunction exhibits a maximum CO production yield of 0.21 mmol g⁻¹ h⁻¹ in the absence of molecular catalysts or scavengers, demonstrating the potential of this material for efficient CO₂ photoreduction.The study investigates the construction of an S-scheme heterojunction between In₂O₃ and Nb₂O₅ to enhance the photocatalytic reduction of CO₂. The heterojunction is fabricated using a one-step electrospinning technique, ensuring intimate contact between the two phases and promoting ultrafast electron transfer (<10 ps) as confirmed by femtosecond transient absorption spectroscopy. This results in the accumulation of powerful photoelectrons in the Nb₂O₅ conduction band and photoholes in the In₂O₃ valence band, extending their lifetimes and facilitating their involvement in subsequent photoreactions. The chemisorption and activation of CO₂ on Nb₂O₅ further enhance the photocatalytic performance of the In₂O₃/Nb₂O₅ hybrid nanofibers. The optimized heterojunction exhibits a maximum CO production yield of 0.21 mmol g⁻¹ h⁻¹ in the absence of molecular catalysts or scavengers, demonstrating the potential of this material for efficient CO₂ photoreduction.