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‐H2 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 H2 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 H2 and O2 generation.

2D/2D Boron/g-C3N4 Nanosheet Heterojunction Boosts Photocatalytic Hydrogen Evolution Performance

“…In general, UV–vis diffuse reflectance spectroscopy has beneficially verified that BNS helps to enhance the absorption of visible light by the composite material, thereby enhancing the performance of photocatalysis. PL spectroscopy analysis further supports the above view, which reflects electron–hole recombination and its efficiency of trapping charge carriers . The PL spectra in Figure b illustrated that all samples gain the emission peaks excited by the 365 nm wavelength.…”

Bifunctional thioacetamide-mediated synthesis of few-layered MoOSx nanosheet-modified CdS hollow spheres for efficient photocatalytic H2 production

“…10B and C). [56][57][58] Therefore, the obtained fewlayered MoOS x nanosheet-cocatalysts not only efficiently accelerate the charge migration, but also significantly promote the interfacial H 2 -evolution performance.…”

Electrocatalytic activity of metal encapsulated, doped, and engineered fullerene-based nanostructured materials towards hydrogen evolution reaction

“…In recent years, fullerene which is a carbon-based material has emerged as a potential candidate for use as noble-metal free electrocatalysts for the hydrogen evolution reaction (HER, 2H + (aq) + 2e ⇄ H2(g)), which is a cathodic half-reaction of water splitting 1 , 2 . This is due to the enormous importance of fullerene which include low price, abundant reserves, and long- term stability 3 . Hydrogen has been known as a key energy carrier, and its electrocatalytic reaction is a cathodic reaction in water electrolysis, while its anodic reaction which is hydrogen oxidation reaction (HOR) is an anodic reaction in fuel cells 4 .…”