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Exploring high efficiency S‐scheme heterojunction photocatalysts with strong redox ability for removing volatile organic compounds from the air is of great interest and importance. However, how to predict and regulate the transport of photogenerated carriers in heterojunctions is a great challenge. Here, density functional theory calculations were first used to successfully predict the formation of a CdS quantum dots/InVO4 atomic‐layer (110)/(110) facet S‐scheme heterojunction. Subsequently, a CdS quantum dots/InVO4 atomic‐layer was synthesized by in‐situ loading of CdS quantum dots with (110) facets onto the (110) facets of InVO4 atomic‐layer. As a result of the deliberately constructed built‐in electric field between the adjoining facets, we obtain a remarkably enhanced photocatalytic degradation rate for ethylene. This rate is 13.8 times that of pure CdS and 13.2 times that of pure InVO4. In‐situ irradiated X‐ray photoelectron spectroscopy, photoluminescence and time‐resolved photoluminescence measurements were carried out. These experiments validate that the built‐in electric field enhanced the dissociation of photoexcited excitons and the separation of free charge carriers, and results in the formation of S‐scheme charge transfer pathways. The reaction mechanism of the photocatalytic C2H4 oxidation is investigated by in‐situ electron paramagnetic resonance. This work provides a mechanistic insight into the construction and optimization of semiconductor heterojunction photocatalysts for application to environmental remediation. [ABSTRACT FROM AUTHOR]

Hierarchical ZnO nanosheet-reduced graphene oxide (RGO) nanocomposites were prepared via a simple one-step process under ambient conditions. The resultant ZnO–RGO nanocomposites are composed of highly branched ZnO nanosheets with RGO sheet decoration. It is found that GO precursors could modulate the branched structure of ZnO nanosheets effectively. The shape of hierarchical ZnO nanosheets is effectively tuned by controlling the weight ratio of GO during the synthesis. The ZnO–RGO composites exhibit good photocatalytic performance for ethylene oxidation under simulated sunlight illumination. The photocatalytic oxidation performance of ZnO–RGO photocatalysts could be further enhanced by optimizing the mass ratio of GO to 2%, which showed excellent stability as well. The mineralization rate of ethylene is ∼100% in this reaction. The detailed characterization revealed that the enhanced photo-oxidation performance was attributed to the intimate contact between RGO nanosheets and ZnO nanoparticles, which played important roles in increasing light absorption intensity and promoting the separation and migration of the photoinduced charge carriers. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of ethylene under visible light remains a challenge at the frontiers of chemistry. In this study, In 2 O 3 -Ag-Ag 3 PO 4 composite semiconductors with Z-scheme configuration were fabricated for the first time by in-situ synthesis of Ag 3 PO 4 on In 2 O 3 and subsequent photoreduction of Ag 3 PO 4 to generate nano silver. Their performances on photocatalytic degradation of ethylene under visible light illumination were investigated. Results demonstrated that both the activity of ethylene photocatalytic degradation and Ag 3 PO 4 photostabilization are considerably improved by making such a Z-scheme composite. According to the material design perspective and the application in the field of environmental pollutant remediation, the present research will provide potential value for further study on the removal of HC (Hydrocarbons) from the atmosphere and the stability concern of Ag 3 PO 4 and other materials with photocorrosion. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoO was first used as C 2 H 4 degradation photocatalyst in this study. • A 0D/2D CoO QDs/Bi 2 MoO 6 monolayer S-scheme heterojunction is built. • This photocatalyst shows outstanding visible light activities for C 2 H 4 degradation. • The S-scheme heterojunction enhances the stability of CoO in photocatalytic reaction. • The S-scheme heterojunction could apply in fruit and vegetable preservation. As a plant hormone, C 2 H 4 causes significant economic losses during the storage and transportation of fruits and vegetables. How to efficiently photocatalytic oxidation of atmospheric C 2 H 4 using sun-light remains a significant challenge at the frontiers of chemistry. Inspired by natural photosynthesis of plant, here, we design a novel S-scheme heterojunction for highly efficient photocatalytic C 2 H 4 degradation. We first conducted density functional theory (DFT) calculations to predict an S-scheme heterojunction can be formed between CoO and Bi 2 MoO 6 , and then fabricated a novel CoO Quantum dots (QDs)/Bi 2 MoO 6 monolayer S-scheme heterojunction by using a practical hydrothermal approach to in-situ deposit CoO QDs on a Bi 2 MoO 6 monolayer. Furthermore, the UV–Vis DRS, UPS, in-situ XPS and electron spin resonance (ESR) characterization of DMPO-•O 2 – signals and DMPO-•OH signals evidence that the transfer pathway of space charge in photocatalytic degradation of ethylene accords with the S-scheme. Moreover, due to the unique structural design, CoO QDs and Bi 2 MoO 6 monolayer form an S-scheme heterojunction, and the intimate contact that enables efficient charge transfer and sufficient redox ability simultaneously, the CoO QDs/Bi 2 MoO 6 monolayer catalyst achieves a remarkable ethylene photocatalytic-degradation rate of 3.27 × 10−2∙min−1, 19.2 times higher than CoO and 22.5 times higher than Bi 2 MoO 6. This work provides novel insights for designing efficient S-scheme photocatalysts for C 2 H 4 degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ternary core–shell nanostructures were obtained by a facile and surfactant free method. • The resultant Pd-SNOF@SnO 2 shows efficient photoactivity for C 2 H 4 oxidation. • The core–shell structure can obviously improve the charge separation efficiency. A ternary core–shell structure composed of Sn 1.1 Nb 2 O 5.5 F 0.9 (SNOF), Pd nanoparticles, and the SnO 2 was fabricated by a facile one-step process at room temperature. In this structure, the SNOF nano-octahedrons were coated with thin layers of SnO 2 , and Pd nanoparticles were embedded in the SnO 2 matrix. The formation of SnO 2 and Pd nanomaterials was induced by the redox reaction between the reductive Sn2+ ions of the SNOF and the H 2 PdCl 4 solution. During this process, there are no organic species or foreign reducing agents involved. The as-obtained Pd-Sn 1.1 Nb 2 O 5.5 F 0.9 @SnO 2 (Pd-SNOF@SnO 2) nanocomposites showed efficient photoactivities for C 2 H 4 oxidation under simulated sunlight irradiation, which was significantly higher than that of the blank SNOF. The mineral ratio was determined to be ∼ 100%, and the catalyst was stable after five cycles. This result was ascribed to the core–shell structure of SNOF and SnO 2 as well as the embedded Pd nanoparticles functioning as an electron trapping site, which can effectively accept the photo-excited electrons. [ABSTRACT FROM AUTHOR]

Achieving efficient photocatalytic degradation of atmospheric volatile organic compounds (VOCs) under sun-light is still a significant challenge for environmental protection. The S-scheme heterojunction with its unique charge migration route, high charge separation rate and strong redox ability, has great potential. However, how to regulate interfacial charge transfer of the S-scheme heterojunction is of significant importance. Here, density functional theory (DFT) calculations were first conducted and predicted that an S-scheme heterojunction could be formed in the CdS quantum dots/Bi 2 MoO 6 monolayer system. Subsequently, this novel heterojunction is constructed by in-situ hydrothermal synthesis of CdS quantum dots on monolayer Bi 2 MoO 6. Under visible-light, this novel S-scheme system gives a high-efficiency photocatalytic degradation rate (6.04 × 10−2 min−1) towards C 2 H 4 , which is 30.3 times higher than that of pure CdS (1.99 × 10−3 min−1) and 41.7 times higher than pure Bi 2 MoO 6 (1.45 × 10−3 min−1). Strong evidence for the S-scheme charge transfer path is provided by in-situ XPS, PL, TRPL and EPR. [Display omitted] • A novel S-scheme CdS QDs/Bi 2 MoO 6 monolayer photocatalyst was synthesized. • This S-scheme heterojunction shows excellent activities for C 2 H 4 photodegradation. • The reaction mechanism of C 2 H 4 photooxidation was comprehensively investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Designed and fabricated a CdS QDs/Bi 2 WO 6 monolayer S-scheme heterojunction. • Bi-S bonds deliberately introduced at the interface to regulate the charge transfer. • S-scheme heterojunction show excellent photoactivities for C 2 H 4 oxidation. The S-scheme heterojunction with unique photogenerated electrons and holes migration pathway, excellent separation efficiency of photogenerated carrier and high redox potential, has great potential in this field of photocatalytic oxidation of atmospheric C 2 H 4. However, optimising the transfer of photogenerated charge at the S-scheme heterostructure interface continues to a major challenge. Here, density functional theory (DFT) calculations were first conducted to predict an S-scheme heterojunction can be formed in the CdS quantum dots (QDs)/Bi 2 WO 6 monolayer system, and then CdS QDs/Bi 2 WO 6 monolayer S-scheme heterojunction were constructed by in-situ hydrothermal synthesis of CdS QDs onto Bi 2 WO 6 monolayer. Bi-S bonds are deliberately introduced at the interface to maximise the photogenerated charge transfer. As expected, the substantial enhancement of the photocatalytic degradation of ethylene and the photostabilization of CdS is demonstrated. The S-scheme band alignment and the connected Bi-S coordination introduced at the junction interface allow highly efficient charge separation and an effective interfacial charge migration path. This research provides a basis for understanding the design of materials for the removal of hydrocarbons in air and environmental pollutant remediation, and improving the stability of sulfide and other photocatalysts to photocorrosion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel Ti 0.5 Ru 0.5 O 2 /TiO 2 (B)/TiO 2 (A) nanosheets are constructed. • The nanosheets exhibits a remarkable photothermal synergistic H 2 evolution rate. • Ti 0.5 Ru 0.5 O 2 shows much better co-catalytic ability compared to Ru and RuO 2. TiO 2 is an important material used in photocatalytic H 2 evolution. Here nanosheets with a Ti 0.5 Ru 0.5 O 2 /TiO 2 (B)/TiO 2 (A) three-phase-junctions, composed of solid solution rutile phase Ti 0.5 Ru 0.5 O 2 , bronze phase TiO 2 (B), and anatase phase TiO 2 (A), are constructed via a hydrothermal method and subsequent calcination. At the optimal calcination temperature of 350 °C, the highest H 2 evolution rate reaches 27.817 mmol∙g−1∙h−1 at 25 °C, which is further increased up to 62.357 mmol∙g−1∙h−1 at 70 °C by synergistic photothermal catalysis. The photocatalytic activity of the optimized catalyst was further enhanced by loading with Pt as a co-catalyst. It is found that, in addition to helping charge separation, migration, and inhibiting the charge recombination, the three-phase-junctions structure is a key to present strong oxidation and reduction ability. Ti 0.5 Ru 0.5 O 2 solid solution has excellent co-catalytic ability, much better than Ru oxide, metallic Ru, as well as Pt. It works as hole acceptor, accelerating the generation and quench of photo induced peroxyl radicals, and thus significantly enhancing the H 2 generation rate. [ABSTRACT FROM AUTHOR]

• Poto-deposited Hexagonal CdS/TiO 2 (B) shows visible light catalytic activity. • Hydrothermal fabricated Cubic CdS/TiO 2 (B) shows only UV light catalytic activity. • The photocorrosion resistance of CdS/TiO 2 (B) can be enhanced by PVP modification. A conventional TiO 2 photocatalyst cannot respond to visible light due to its large band gap. Here, we describe the construction of tandem CdS/TiO 2 (B) nanosheet architectures with visible light H 2 evolution. A type II heterojunction of hexagonal CdS/TiO 2 (B) (PCT) was constructed by photodeposition and CdS dots, with size about 6 nm, were anchored on TiO 2 (B) nanosheets. A second type I heterojunction of cubic CdS/TiO 2 (B) (HCT) was fabricated by a hydrothermal method and CdS nanoparticles, with size about 50 nm, were dispersed on TiO 2 (B) nanosheets. Both heterojunction systems display remarkable enhancement of H 2 evolution activity under full spectrum irradiation, with highest H 2 evolution rate of 1776 μmol·g−1·h−1 for the photodeposited catalyst and 1494 μmol·g−1·h−1 for the hydrothermal process. The different heterojunction systems show very different H 2 evolution under just visible light irradiation. The highest H 2 evolution (1577 μmol·g−1·h−1) for the type II system is far much higher than the type I (48 μmol·g−1·h−1). The type II system shows more effective utilization of full spectrum with the apparent quantum efficiency in the wavelength range extended from 300 to 500 nm, matching well with the optical absorbance spectrum of the composite catalyst. The structure, morphology, and photocatalytic mechanism of the CdS/TiO 2 (B) composites are discussed. [ABSTRACT FROM AUTHOR]