Morphology and doping engineering of sulfur-doped g-C3N4 hollow nanovesicles for boosting photocatalytic hydrogen production

Abstract

The rational design and directional synthesis of desirable structural heteroatom-doped graphitic carbon nitride (CN) is of great significance for achieving efficient photocatalytic hydrogen evolution (HER) performance, but challenges remain. Herein, we have successfully developed an attractive sulfur-doped hollow CN nanovesicle (HV-SCN) photocatalyst via supramolecular self-assembly strategy. The engineered HV-SCN not only possesses large specific surface area, strong hydrophilicity and high light absorption capacity, but also displays efficient photogenerated carrier excitation and transfer efficiency. Consequently, the resultant HV-SCN achieves an extremely high H2 generation rate of 9.49 mmol h-1 g-1. Subsequent density functional theory (DFT) calculations and band configuration results confirm that S-doping induces band gap shortening and favorable hydrogen adsorption, which confers enhanced photocatalytic HER performance of HV-SCN. Furthermore, the catalytic mechanism and carrier migration dynamics are confirmed by in situ X-ray photoelectron and femtosecond transient absorption spectroscopy (fs-TAS). This study provides valuable experimental and theoretical references for the rational design and directional preparation of high-performance catalysts.