The g-C3N4/Bi2Sn2O7@PAN nanofibes: Enhanced photocatalytic activity in H2 evolution by the formation of heterojunction and in-situ growth

To investigate the influence of heterojunction and in-situ growth on photocatalytic activity, the g-C3N4, Bi2Sn2O7 and g-C3N4/Bi2Sn2O7@PAN photocatalysts were fabricated. The phase, composition, microstructure, optical and electrochemical characteristics, as well as photocatalytic activity in photocatalytic H2 evolution were investi-gated. The XRD pattern and EDX spectrum indicate the composited phase of the g-C3N4/Bi2Sn2O7@PAN. The SEM and TEM images, as well as the XPS spectra indicate the heterojunction constitution between the g-C3N4 and Bi2Sn2O7. The g-C3N4/Bi2Sn2O7@PAN has the more efficient light harvesting, separation and migration of photogenerated charge carriers, which are revealed by the DRS, emission spectra, photocurrent responses and EIS spectra. In addition, the LSV curves also indicate that g-C3N4/Bi2Sn2O7@PAN has the higher activity in PHE process. Under the irradiation of simulated sunlight, the g-C3N4/Bi2Sn2O7@PAN shows the higher H2 production velocity, which is -2.09 and 1.59 times those of g-C3N4 and Bi2Sn2O7.