Synthesis, photocatalytic hydrogen evolution performance of Zn0.5Cd0.5S/TiO2 S-scheme heterojunction nanofibers

Photocatalytic hydrogen evolution from water has emerged as a pivotal approach for the generation of sustainable energy. In this study, the Zn 0.5 Cd 0.5 S/TiO 2 ( x ZCST, where x denotes the molar ratio of ZCS to TiO 2 ) nanofibers S-scheme heterojunction is successfully synthesized via the hydrothermal deposition of Zn 0.5 Cd 0.5 S (ZCS) nanoparticles onto the surface of TiO 2 nanofibers. In comparison to pure TiO 2 and ZCS, the as-prepared x ZCST photocatalyst exhibits a significantly enhanced photocatalytic hydrogen evolution performance. Under simulated sunlight irradiation, a maximum hydrogen evolution rate of 16.68 mmol g −1  h −1 is achieved in the 3ZCST sample, which corresponds to 1.78 times that of ZCS and 57.52 times that of TiO 2 , respectively. Further investigations have substantiated the formation of the internal electric field and charge transfer process within the S-scheme heterojunction, demonstrating the difference between the Fermi levels of TiO 2 and ZCS, as well as the migration of electrons from TiO 2 to ZCS under illumination. Such an S-scheme heterojunction is also found to effectively facilitate the separation of photogenerated electron-hole pairs and preserve strong redox capabilities, significantly enhancing photocatalytic hydrogen production. These findings offer valuable insights and guidance for designing high-performance S-scheme heterojunction photocatalysts.