摘要： Sodium niobate nanofibers (NaNbO3-NF) have been synthesized by hydrothermal technique and further coupled with visible light responsive graphitic carbon nitride (g-C3N4) nanosheets in the different concentration ratio of 2:1 (2-CN), 4:1 (4-CN) and 8:1 (8-CN). A significant improvement in the photoelectrochemical (PEC) performance of g-C3N4/NaNbO3-NF (4-CN) nanostructured photoanode as compared to bare NaNbO3 photoanode is observed. A current density of 12.55 mA cm?2 at 1 V with respect to Ag/AgCl reference electrode is achieved for g-C3N4/NaNbO3-NF (4-CN) photoanode which is ~3 times higher than the NaNbO3-NF photoanode. Also, as compared to NaNbO3-NF, g-C3N4/NaNbO3-NF (4-CN) nanocomposite photoanode showed ~3 times improvement in the incident photon-to-current conversion efficiency. The improvement in the PEC performance of visible light active g-C3N4/NaNbO3-NF (4-CN) nanocomposite is attributed to the improved photoresponse of NaNbO3-NF due to the coupling of g-C3N4 and formation of type-II heterojunction between them leading to the enhanced separation of the photogenerated charge carriers. A possible reaction mechanism for the improved photoelectrochemical water splitting performance has been proposed for g-C3N4/NaNbO3-NF (4-CN) photoanode.