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To conquer the disadvantage of low photocatalytic efficiency resulted from narrow photoresponse range and electron-hole recombination, a 2D nanoplate-like MoS 2 /Bi 2 WO 6 heterojunction photocatalyst was designed and prepared by a facile two-step hydrothermal technique. Compared with pure Bi 2 WO 6 , the MoS 2 / Bi 2 WO 6 composite displayed an enhanced photoabsorption in the whole visible light region. Through the photodegradation of rhodamine B (RhB) under visible light irradiation (λ>400 nm), the photocatalytic activities of the obtained products were evaluated and the MoS 2 /Bi 2 WO 6 composite exhibited higher photocatalytic performance than that of pure Bi 2 WO 6 . The enhanced photocatalytic performance was attributed to the broad photoabsorption and low charge recombination driven by the photogenerated potential difference formed at the MoS 2 /Bi 2 WO 6 heterojunction interface. [ABSTRACT FROM AUTHOR]

The rational design of hierarchical heterojunction photocatalysts with efficient spatial charge separation remains an intense challenge in hydrogen generation from photocatalytic water splitting. Herein, a noble-metal-free MoS 2 /g-C 3 N 4 /ZnIn 2 S 4 ternary heterostructure with a hierarchical flower-like architecture was developed by in situ growth of 3D flower-like ZnIn 2 S 4 nanospheres on 2D MoS 2 and 2D g-C 3 N 4 nanosheets. Benefiting from the favorable 2D-2D-3D hierarchical heterojunction structure, the resultant MoS 2 /g-C 3 N 4 /ZnIn 2 S 4 nanocomposite loaded with 3 wt% g-C 3 N 4 and 1.5 wt% MoS 2 displayed the optimal hydrogen evolution activity (6291 μmol g−1 h−1), which was a 6.96-fold and 2.54-fold enhancement compared to bare ZnIn 2 S 4 and binary g-C 3 N 4 /ZnIn 2 S 4 , respectively. Structural characterizations reveal that the significantly boosted photoactivity is closely associated with the multichannel charge transfer among ZnIn 2 S 4 , MoS 2 , and g-C 3 N 4 components with suitable band-edge alignments in the composites, where the photogenerated electrons migrate from g-C 3 N 4 to ZnIn 2 S 4 and MoS 2 through the intimate heterojunction interfaces, thus enabling efficient electron-hole separation and high photoactivity for hydrogen evolution. In addition, the introduction of MoS 2 nanosheets highly benefits the improved light-harvesting capacity and the reduced H 2 -evolution overpotential, further promoting the photocatalytic H 2 -evolution performance. Moreover, the MoS 2 /g-C 3 N 4 /ZnIn 2 S 4 ternary heterostructure possesses prominent stability during the photoreaction process owing to the migration of photoinduced holes from ZnIn 2 S 4 to g-C 3 N 4 , which is deemed to be central to practical applications in solar hydrogen production. [ABSTRACT FROM AUTHOR]

Exploring efficient and robust photocatalysts for solar hydrogen generation from water reduction is great significant in solving the energy shortage and environment contamination simultaneously. Herein, benefiting from the matchable energy band structures and band bending, the direct Z-scheme ZnIn 2 S 4 /NiWO 4 heterojunctions were successfully constructed by anchoring p-type NiWO 4 nanoparticles onto n-type ZnIn 2 S 4 nanosheets through a facile sonochemical route. By carefully regulating the interfacial structure, the optimized ZnIn 2 S 4 /NiWO 4 heterostructure without any cocatalyst displays excellent stability and remarkably improved photocatalytic hydrogen evolution activity (16.3 mmol∙g−1∙h−1), more 3.57-folds increment than bare ZnIn 2 S 4 photocatalyst. Mechanistic characterizations demonstrate that the dramatically boosted photocatalytic performance mainly results from the constructed Z-scheme heterostructure and intimately interfacial contact between ZnIn 2 S 4 and NiWO 4 , which results in the valid interfacial charge transfer channels, powerful redox potential and reduced hydrogen evolution energy barrier, as confirmed by the joint analysis of electron spin resonance (ESR) and photoelectrochemical measurements. More importantly, the photoinduced holes of ZnIn 2 S 4 are rapidly and effectively consumed in the unique Z-scheme charge transfer channels, which greatly favors the suppression of the photocorrosion caused by insufficient hole extraction during the photocatalytic reaction, thereby promoting the overall stability and reusability of the ZnIn 2 S 4 /NiWO 4 composite photocatalyst. This study paves the way for constructing other Z-scheme nano-heterostructure consisting of p-type and n-type semiconductors with efficient photoactivity and robust stability for energy and environmental applications. [Display omitted] • Z-scheme heterojunction consisting of p-type and n-type semiconductors was designed. • Mechanism for the enhanced photoactivity over ZnIn 2 S 4 /NiWO 4 heterojunction discussed. • High H 2 -production rate achieved over heterojunction, 3.57-fold higher than ZnIn 2 S 4. [ABSTRACT FROM AUTHOR]