Durian-Shaped CdS@ZnSe Core@Mesoporous-Shell Nanoparticles for Enhanced and Sustainable Photocatalytic Hydrogen Evolution

Abstract

In artificial photosynthesis, the establishment of design guidelines for nanostructures to maximize the photocatalytic performance remains a great challenge. In contrast with the intense research into band-offset tuning for photocatalysts, the relationship between nanostructures and photoinduced carrier dynamics has still been insufficiently explored. We synthesized durian-shaped CdS@ZnSe core@mesporous-shell nanoparticles ( d-CdS/ZnSe NPs) and investigated the carrier dynamics in photocatalytic hydrogen evolution. The cocatalyst-free d-CdS/ZnSe NPs exhibited high photocatalytic activity for H evolution (14.8% apparent quantum yield at 420 nm) and excellent stability (maintaining 80% activity after 72 h) under visible-light irradiation (>422 nm). The transient absorption measurement and flash photolysis time-resolved microwave conductivity unveiled that the ultra-long-lived charge separation (>6.2 ms) and swift hole transfer to the surfaces of ZnSe shell (11 ns) contribute the high catalytic activity and stability. The present work provides a novel insight into designing nanoparticulate photocatalysts with optimized performance.

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

“…Figure 4c shows a decay process of XB over ≈5–3000 ps, corresponding to the long‐lived single exciton state. [ 36 ] Similarly, the fs‐TAS of the CdS‐F/G composite exhibits the state filling of the 1S(e)–1S 3/2 (h) transitions with ground‐state bleaching, as shown in Figure 4d. Compared to the CdS, the rapid dissociation of hot excitons directly caused XA1 quenching in CdS‐F/G (Figure 4d).…”

“…[ 35 ] The rapid decay of the XA1 absorption directly causes the bleaching of the band‐edge exciton band. [ 36 ] The red‐shift of XA2 (450 nm) reflects the interaction of the 1Σ exciton with other exciton bands. Compared to pristine CdS, CdS‐F/G shows a broad photo‐induced absorption (PIA) at a high‐frequency range (600–750 nm), assigned to the hole trapping in the CdS phase.…”

Boosting Visible‐Light Photocatalytic Redox Reaction by Charge Separation in SnO2/ZnSe(N2H4)0.5 Heterojunction Nanocatalysts

“…We therefore supposed that the decreasing photocurrent density origi- nated from electrolyte depletion as well as the dissolution of selenide ions into the electrolyte due to photocorrosion. [55,56] Electrochemical impedance spectroscopy (EIS;F igure 5b)w as also conducted to study the interfacial characteristics of the photocatalysts. As displayed in Figure 5b,t he SnO 2 / ZnSe(N 2 H 4 ) 0.5 nanocomposites displayed as maller arc diameter than that of ZnSe(N 2 H 4 ) 0.5 ,i ndicating its lower charge-transfer resistance.…”

Metal Cation Valency Dependence in Morphology Evolution of Cu2−xS Nanodisk Seeds and Their Pseudomorphic Cation Exchanges

“…The properties of colloidal inorganic nanoparticles (NPs) including catalytic, electronic, optical, and magnetic performances are greatly affected by their morphologies, suggesting opportunities for enabling applications, which are not possible by poorly defined or bulk materials [1–5] . In recent years, the morphology and according properties of Zn– and Cd–chalcogenide compositions have been exploited and rationalized [6–15] . Nevertheless, their further development into particular applications are somewhat limited by the concerns of fabrication technique for complex (hetero)structures.…”

“…[1][2][3][4][5] In recent years, the morphologya nd according properties of Zn-and Cd-chalcogenide compositions have been exploited and rationalized. [6][7][8][9][10][11][12][13][14][15] Nevertheless, their furtherd evelopment into particular applications are somewhat limited by the concerns of fabrication technique for complex (hetero)structures. To circumvent this obstacle, an attractive alternative strategy is cation exchange (CE).…”