Boosting hydrogen evolution performance of nanofiber membrane-based composite photocatalysts with multifunctional carbon dots

Abstract

Recent progress in the co-spinning of nanofibers and semiconductor particles offers a promising strategy for the development of photocatalytic devices, solving aggregation and catalyst recovery challenges. However, composite photocatalysts based on nanofiber membranes often suffer from poor conductivity, low hydrophilicity, and easy recombination of photogenerated electron-hole pairs in the semiconductor components. Here, to tackle the aforementioned issues of ZnIn₂S₄/polyacrylonitrile (ZIS/PAN) nanofiber-based catalysts, we prepared a composite carbon dots/ZnIn₂S₄/polyacrylonitrile (CZP) nanofiber membrane by blending carbon dots (CDs) with ZIS/PAN using the electrospinning process. The hydrogen evolution performance of the CZP photocatalyst was significantly improved by CDs, which enhanced the hydrophilicity, increased the light absorption, facilitated the transfer of photogenerated electrons, and reduced the recombination of photogenerated electron-hole pairs. Notably, the optimal CZP photocatalyst achieved a hydrogen evolution rate of 2250 μmol g^-1h⁻¹, which is about 23 % higher than that of the nanofiber membrane without CDs and 4.55 times higher than that of ZIS particles. The present work successfully improved the CZP nanofiber membrane of photocatalytic hydrogen evolution performance, and the membrane may benefit further device development by eliminating the need for stirring and simplifying the recovery process.