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In this work, a new kind of CdS–ZnO core–shell nanorods with controlled ZnO shell are first synthesized by a simple chemical deposition method in aqueous solution. The thickness and distribution of the ZnO shell can be accurately adjusted, and intimate contact interfaces between CdS and ZnO are well constructed. The optimal CSZ0.5 core–shell heterostructure exhibits a photocatalytic H2 evolution rate of 805.5 μmol h−1 without co-catalysts (3 mg of catalyst, equal to 268.5 mmol g−1 h−1), which is 12 and 895 times higher than that of CdS and ZnO, respectively, and is the maximum value among CdS-based photocatalysts under similar experimental conditions. The significant enhancement in the photocatalytic H2 evolution rate can be mainly attributed to three positive factors: the single-crystalline structure of CdS, the Z-scheme mechanism formed between CdS and ZnO, and the introduced ascorbic acid. The first two factors effectively promote the separation and migration of charge carriers, and the latter factor realizes efficient hydrogen spillover for CdS/ZnO to accelerate the photocatalytic hydrogen evolution reaction. In addition, the homogeneous ZnO shell grown on the CdS core efficiently suppresses the photo-corrosion of CdS, which endows CdS/ZnO with outstanding photostability. [ABSTRACT FROM AUTHOR]

It is facing a tremendous challenge to develop the desirable hybrids for photocatalytic H 2 generation by integrating the advantages of a single semiconductor. Herein, an all-sulfide ZnIn 2 S 4 /CdS/PdS heterojunction is constructed for the first time, where CdS and PdS nanoparticles anchor in the spaces of ZnIn 2 S 4 micro-flowers due to the confinement effects. The morphology engineering can guarantee rapid charge transfer owing to the short carrier migration distances and the luxuriant reactive sites provided by ZnIn 2 S 4 . The S-scheme mechanism between ZnIn 2 S 4 and CdS assisted by PdS cocatalyst is testified by in situ irradiated X-ray photoelectron spectroscopy and electron paramagnetic resonance (EPR), where the electrons and holes move in reverse driven by work function difference and built-in electric field at the interfaces. The optimal ZnIn 2 S 4 /CdS/PdS performs a glaring photocatalytic activity of 191.9 µmol h -1 (10 mg of catalyst), and the largest AQE (apparent quantum efficiency) can reach a high value of 26.26%. This work may afford progressive tactics to design multifunctional photocatalysts., (© 2023 Wiley-VCH GmbH.)

Herein, a new photocatalyst PdS@UiOS@CZS is successfully synthesized, where thiol-functionalized UiO-66 (UiOS), a metal-organic framework (MOF) material, is used as a host to encapsulate PdS quantum dots (QDs) in its cages, and Cd 0.5 Zn 0.5 S (CZS) solid solution nanoparticles (NPs) are anchored on its outer surface. The resultant PdS@UiOS@CZS with an optimal ratio between components displays an excellent photocatalytic H 2 evolution rate of 46.1 mmol h -1 g -1 under visible light irradiation (420∼780 nm), which is 512.0, 9.2, and 5.9 times that of pure UiOS, CZS, and UiOS@CZS, respectively. The reason for the significantly enhanced performance is that the encapsulated PdS QDs strongly attract the photogenerated holes into the pores of UiOS, while the photogenerated electrons are effectively migrated to CZS due to the heterojunction effect, thereby effectively suppressing the recombination of charge carriers for further high-efficiency hydrogen production. This work provides an idea for developing efficient photocatalysts induced by hole attraction.