Fullerene–Graphene Acceptor Drives Ultrafast Carrier Dynamics for Sustainable CdS Photocatalytic Hydrogen Evolution

Abstract Ultrafast excited‐state decay and intrinsic charge carrier recombination restrain the photoactivity enhancement for solar‐to‐H 2 production. Here, a CdS‐fullerene/graphene (CdS‐F/G) photocatalyst is synthesized for enhancing visible‐light‐driven hydrogen generation from earth‐abundant water. The CdS‐F/G shows ultrafast interfacial electrons/holes transfer and holes self‐trapping process in photocatalysis. The in‐situ dynamic study from transient absorption spectroscopy reveals the sub‐microsecond‐lived excited states (≈172.6 ns), interfacial electron transfer (≈30.3 ps), and hole trapping (≈44.0 ps) in the CdS‐F/G photocatalyst. The efficient active species transportation and prolonged lifetime significantly enhance the charge separation state survival, increasing the photoactivity and photostability. Consequently, visible‐light activity enhancement (>400%) of H 2 evolution reaction (HER) is obtained at the CdS‐F/G photocatalyst with high stability (>36 h). The 127.2 µmol h −1 g −1 performance corresponding to a quantum efficiency of 7.24% at 420 nm is not only higher than the case of pristine CdS (29.2 µmol h −1 g −1 ) but also much higher than that of CdS‐Pt photocatalyst (73.8 µmol h −1 g −1 ). The cost‐effective CdS‐F/G photocatalyst exhibits a great potential for sustainable and high‐efficiency photocatalytic water splitting into clean energy carriers. Moreover, the optimized electronic structure associated with interfacial electrons/holes transfer and holes self‐trapping promotes overall water splitting for H 2 and O 2 generation.