UV-visible light-induced photochemical synthesis of benzimidazoles by coomassie brilliant blue coated on W–ZnO@NH2 nanoparticles

Heterogeneous photocatalysts proffer a promising method to actualize eco-friendly and green organic transformations. Herein, a new photochemical-based methodology is disclosed in the preparation of a wide range of benzimidazoles through condensation of o-phenylenediamine with benzyl alcohols in the air under the illumination of an HP mercury lamp in the absence of any oxidizing species catalyzed by a new photocatalyst W–ZnO@NH₂–CBB. In this photocatalyst, coomassie brilliant blue (CBB) is heterogenized onto W–ZnO@NH₂ to improve the surface characteristics at the molecular level and enhance the photocatalytic activity of both W–ZnO@NH₂ and CBB fragments. This unprecedented heterogeneous nanocatalyst is also identified by means of XRD, FT-IR, EDS, TGA-DTG, and SEM. The impact of some influencing parameters on the synthesis route and effects on the catalytic efficacy of W–ZnO@NH₂–CBB are also assessed. The appropriate products are attained for both the electron-withdrawing and electron-donating substituents in the utilized aromatic alcohols. Furthermore, preparation of benzimidazoles is demonstrated to occur mainly via a radical mechanism, which shows that reactive species such as ·O₂⁻, OH˙ and h⁺ would be involved in the photocatalytic process. Stability and reusability studies also warrant good reproducibility of the nanophotocatalyst for at least five runs. Eventually, a hot filtration test proved that the nanohybrid photocatalyst is stable in the reaction medium. Using an inexpensive catalyst, UV-vis light energy and air, as a low cost and plentiful oxidant, puts this methodology in the green chemistry domain and energy-saving organic synthesis strategies. Finally, the anticancer activity of W–ZnO nanoparticles is investigated on MCF7 breast cancer cells by MTT assay. This experiment reveals that the mentioned nanoparticles have significant cytotoxicity towards the selected cell line.

A new photochemical route is disclosed in the preparation of a wide range of benzimidazoles in air under the illumination of an HP mercury lamp in the absence of any oxidizing species catalyzed by heterogenized W–ZnO@NH₂–CBB.     

Facile synthesis of a WOx/CsyWO3 heterostructured composite as a visible light photocatalyst

In this work, a WO_x/Cs_yWO₃ heterostructured composite was synthesized via a simple pyrolysis method followed by heat treatment under a reducing atmosphere. Optical absorption results revealed the WO_x/Cs_yWO₃ heterostructured composite exhibits a strong absorption tail in the Vis and NIR regions which could have important implications for its photoactivity. The photocatalytic performance of synthesized samples with different Cs/W molar ratios was evaluated by the photodegradation of RhB in aqueous solution under simulated solar light irradiation. The results revealed that the photocatalytic activity of the WO_x/Cs_yWO₃ composite is much higher than those of pure tungsten bronze (Cs_xWO₃, x = 0.32, and 0.5) and pure WO_2.83 samples, where 90% RhB was degraded after 160 min irradiation. Also, the WO_x/Cs_yWO₃ composite exhibits excellent photocatalytic activity for the degradation of MO, MB, RhB, and MG aqueous solution under visible light irradiation. It is proposed that the higher photocatalytic activity of the WO_x/Cs_yWO₃ composite could be attributed to the greater surface adsorption of dye molecules, intense light absorption in the visible and NIR regions, and photogenerated electron–hole separation.

In this work, a WO_x/Cs_yWO₃ heterostructured composite photocatalyst was synthesized via a simple pyrolysis method followed by heat treatment under a reducing atmosphere.     

Highly efficient In2S3/WO3 photocatalysts: Z-scheme photocatalytic mechanism for enhanced photocatalytic water pollutant degradation under visible light irradiation

A Z-scheme system In₂S₃/WO₃ heterojunction was fabricated via a mild hydrothermal method and further applied for photocatalytic degradation of tetracycline (TCH) and Rhodamine B (Rh B) under visible light irradiation. The morphological structure, chemical composition and optical properties were studied by XRD, SEM, HRTEM and UV-visible absorption spectra. The results revealed that In₂S₃/WO₃ hierarchical structures were successfully constructed, and the prepared In₂S₃/WO₃ photocatalysts exhibited enhanced visible-light absorption compared to pure WO₃ nanorods, which are essential to improve the photocatalytic performance. The degradation rate of TCH using the In₂S₃(40 wt%)/WO₃ heterostructure (WI40) photocatalyst was about 212 times and 22 times as high as that for pure WO₃ and pure In₂S₃, respectively. The degradation rate of Rh B with the WI40 photocatalyst was about 56 times the efficiency of pure WO₃ and 7.6 times that of pure In₂S₃. The results of the surface photovoltage (SPV), transient photovoltage (TPV) and reactive oxidation species (ROS) scavenger experiments indicated that the Z-scheme system of In₂S₃/WO₃ is favorable for photoexcited charge transfer at the contact interface of In₂S₃ and WO₃, which benefits the charge separation efficiency and depresses the recombination of photoexcited charge, resulting in favorable photocatalytic pollutant degradation efficiency under visible light irradiation.

A Z-scheme system In₂S₃/WO₃ heterojunction was fabricated via a mild hydrothermal method and further applied for photocatalytic degradation of tetracycline (TCH) and Rhodamine B (Rh B) under visible light irradiation.     

Visible light-mediated photocatalytic oxidative cleavage of activated alkynes via hydroamination: a direct approach to oxamates

The direct oxidative cleavage of activated alkynes via hydroamination has been described using organic photocatalyst under visible-light irradiation at room temperature. In this reaction, the single electron oxidation of an in situ formed enamine followed by radical coupling with an oxidant finally delivers the oxamate. The key features of this photocatalytic reaction are the mild reaction conditions, metal-free organic dye as a photocatalyst, and TBHP playing a dual role as “O” source and for the regeneration of the photocatalyst.

The direct oxidative cleavage of activated alkynes via hydroamination has been described using organic photocatalyst under visible-light irradiation at room temperature.     

ZnO nanorod arrays grown on g-C3N4 micro-sheets for enhanced visible light photocatalytic H2 evolution

The designed synthesis of noble-metal-free photocatalysts with hierarchical heteroassemblies in a facile, mild and eco-friendly way becomes more and more important, because we can explore the novel properties and applications of novel heterostructures via this method. Herein we report a two-step aqueous strategy for novel hierarchical heterostructures of ZnO nanorod (NR) arrays grown on graphitic carbon nitride (g-C₃N₄). The novel g-C₃N₄/ZnO NR heterostructures that integrate g-C₃N₄ and ZnO NR via high-quality g-C₃N₄–ZnO heterojunctions have beneficial properties such as high specific surface area (SSA), open spatial architecture, good electronic conductivity, and effective charge transfer interfaces, and are promising in many related areas such as water splitting, solar cells, etc. As a noble-metal-free and visible-light-responsive photocatalytic material, a typical g-C₃N₄/ZnO NR photocatalytic system exhibits enhanced photocatalytic activity toward H₂ evolution, almost 3.5 times higher than that of pure g-C₃N₄. The superior photocatalytic property can be ascribed to the synergistic effect of the unique g-C₃N₄/ZnO NR heterostructures.

The designed synthesis of photocatalysts with hierarchical heteroassemblies in a facile, mild and eco-friendly way becomes more and more important, since we can explore the novel properties and applications of novel heterostructures via this method.     

A one-pot synthesis of AgBr/Ag3PO4 composite photocatalysts

In this study, an AgBr/Ag₃PO₄ (ABAP) photocatalyst has been prepared via a facile one-pot anion-exchange method. SEM, XRD, XPS and UV-Vis DRS characterization techniques are carried out to study the structural and physicochemical characteristics of the AgBr/Ag₃PO₄ composites. The ABAP photocatalyst exhibited outstanding photocatalytic capability for the photodegradation of rhodamine B (RhB) under visible light irradiation. The optimal ABAP-48% composite displayed the highest photocatalytic activity; a complete degradation was attained in 25 min under visible light irradiation. The excellent stability and reusability of ABAP catalysts were examined by five subsequent runs. A probable degradation mechanism of ABAP composites was carefully surveyed. Furthermore, radical trapping experiments confirmed that the ˙O₂⁻ radical was the main active species in the photodegradation reaction.

In this study, an AgBr/Ag₃PO₄ (ABAP) photocatalyst has been prepared via a facile one-pot anion-exchange method.     

Highly efficient visible light active Cu–ZnO/S-g-C3N4 nanocomposites for efficient photocatalytic degradation of organic pollutants

The photocatalytic activity of photocatalysts is severely hampered by limited visible light harvesting and unwanted fast recombination of photogenerated e⁻ and h⁺. In the current study, the photocatalytic efficiency of Cu–ZnO/S-g-C₃N₄ (CZS) nanocomposites was investigated against MB dye. The composite materials were designed via chemical co-precipitation method and characterised by important analytical techniques. Distinctive heterojunctions developed between S-g-C₃N₄ and Cu–ZnO in the CZS composite were revealed by TEM. The synthesized composites exhibit a huge number of active sites, a large surface area, a smaller size and better visible light absorption. The considerable enhancement in the photocatalytic activity of CZS nanocomposites might be accredited to the decay in the e–h pair recombination rate and a red shift in the visible region, as observed by PL and optical analysis, respectively. Furthermore, the metal (Cu) doping into the S-g-C₃N₄/ZnO matrix created exemplary interfaces between ZnO and S-g-C₃N₄, and maximized the photocatalytic activity of CZS nanocomposites. In particular, CZS nanocomposites synthesized by integrating 25% S-g-C₃N₄ with 4% Cu–ZnO (CZS-25 NCs) exhibited the 100% photocatalytic degradation of MB in 60 minutes under sunlight irradiation. After six cycles, the photocatalytic stability of CZS-25 NCs was excellent. Likewise, a plausible MB degradation mechanism is proposed over CZS-25 NCs based on photoluminescence and reactive species scavenger test observation. The current research supports the design of novel composites for the photocatalytic disintegration of organic contaminants.

The photocatalytic activity of photocatalyst is severely hampered by limited visible light harvesting and unwanted fast recombination of photogenerated e⁻ and h⁺.     

Fabrication,characterization and high photocatalytic activity of Ag–ZnO heterojunctions under UV-visible light

Pure ZnO and Ag–ZnO nanocomposites were fabricated via a sol–gel route, and the obtained photocatalysts were characterized by XRD, SEM, TEM, BET, XPS, PL and DRS. The results showed that Ag⁰ nanoparticles deposit on the ZnO surface and Ag modification has negligible impact on the crystal structure, surface hydroxyl group content and surface area of ZnO. However, the recombination of photogenerated electrons and holes was suppressed effectively by Ag loading. The photocatalytic activity was investigated by evaluating the degradation of MB under xenon lamp irradiation as the UV-visible light source, and the results show that the photocatalytic activity of ZnO significantly improved after Ag modification. Ag–ZnO photocatalysts exhibit higher photocatalytic activity than commercial photocatalyst P25. The degradation degree of MB for 1%Ag–ZnO was 97.1% after 15 min. ˙O₂⁻ radicals are the main active species responsible for the photodegradation process, and Ag–ZnO heterojunctions generate more ˙O₂⁻ radicals, which is the primary reason for the improved photocatalytic performance.

Ag–ZnO heterojunction promotes the separation of photogenerated pairs and thus exhibits high catalytic activity under UV-visible light.     

ZnO decorated Sn3O4 nanosheet nano-heterostructure: a stable photocatalyst for water splitting and dye degradation under natural sunlight

Herein, a facile hydrothermally-assisted sonochemical approach for the synthesis of a ZnO decorated Sn₃O₄ nano-heterostructure is reported. The phase purity of the nano-heterostructure was confirmed by X-ray diffraction and Raman spectroscopy. The morphological analysis demonstrated a nanosheet-like structure of Sn₃O₄ with a thickness of 20 nm, decorated with ZnO. The optical band gap was found to be 2.60 eV for the ZnO@Sn₃O₄ nano-heterostructure. Photoluminescence studies revealed the suppression of electron–hole recombination in the ZnO@Sn₃O₄ nano-heterostructure. The potential efficiency of ZnO@Sn₃O₄ was further evaluated towards photocatalytic hydrogen production via H₂O splitting and degradation of methylene blue (MB) dye. Interestingly, it showed significantly superior photocatalytic activity compared to ZnO and Sn₃O₄. The complete degradation of MB dye solution was achieved within 40 min. The nano-heterostructure also exhibited enhanced photocatalytic activity towards hydrogen evolution (98.2 μmol h⁻¹/0.1 g) via water splitting under natural sunlight. The superior photocatalytic activity of ZnO@Sn₃O₄ was attributed to vacancy defects created due to its nano-heterostructure.

Herein, a facile hydrothermally-assisted sonochemical approach for the synthesis of a ZnO decorated Sn₃O₄ nano-heterostructure is reported.     

Facile one-pot synthesis of heterostructure SnO2/ZnO photocatalyst for enhanced photocatalytic degradation of organic dye

In this work, heterostructure SnO₂/ZnO nanocomposite photocatalyst was prepared by a straightforward one step polyol method. The resulting photocatalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption–desorption analyses, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The results showed that the synthesized SnO₂/ZnO nanocomposites possessed mesoporous wurtzite ZnO and cassiterite SnO₂ nanocrystallites. The photocatalytic activity of the prepared SnO₂/ZnO photocatalyst was investigated by the degradation of methylene blue dye under UV light irradiation. The heterostructure SnO₂/ZnO photocatalyst showed much higher photocatalytic activities for the degradation of methylene blue dye than individual SnO₂, ZnO nanomaterials and reference commercial TiO₂ P25. This higher photocatalytic degradation activity was due to enhanced charge separation and subsequently the suppression of charge recombination in the SnO₂/ZnO photocatalyst resulting from band offsets between SnO₂ and ZnO. Finally, these heterostructure SnO₂/ZnO nanocatalysts were stable and could be recycled several times without any appreciable change in degradation rate constant which opens new avenues toward potential industrial applications.

In this work, heterostructure SnO₂/ZnO nanocomposite photocatalyst was prepared by a straightforward one step polyol method.     

2D–3D graphene-coated diatomite as a support toward growing ZnO for advanced photocatalytic degradation of methylene blue

In this work, a diatomite@graphene@ZnO (ZGD) photocatalyst was synthesized by chemical vapor deposition and hydrothermal methods and used for the photocatalytic degradation of methylene blue. The characterization of the prepared nanocomposite was performed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), and N₂ adsorption–desorption techniques. Ultraviolet-visible diffuse reflectance spectroscopy (DRS) showed that the prepared ZGD photocatalyst enhanced the absorption of visible light and induced a red-shift. Photoluminescence spectroscopy (PL) revealed that the recombination of electron and hole pairs can be effectively suppressed. Besides, the synergistic effect of diatomite and graphene avoids the agglomeration of ZnO, increases the number of surface adsorption sites, and limits the electron transport, consequently improving the photocatalytic activity of ZnO. When ZGD-3 was UV-irradiated (λ = 663 nm) for 90 minutes, the degradation effectiveness of methylene blue (MB) was 100%. After the fifth repetition, the photocatalytic degradation efficiency was always greater than 95%. Simply put, the ZGD nanocatalyst can be used as an efficient photocatalyst for dye wastewater treatment.

In this work, a diatomite@graphene@ZnO (ZGD) photocatalyst was synthesized by chemical vapor deposition and hydrothermal methods and used for the photocatalytic degradation of methylene blue.     

C-doped ZnO decorated with Au nanoparticles constructed from the metal–organic framework ZIF-8 for photodegradation of organic dyes

Recently, engineering metal–organic frameworks (MOFs) into metal oxides by solid state thermal decomposition has attracted wide attention for photocatalytic applications. Here, a series of C-doped ZnO materials decorated with Au nanoparticles (Au/C-ZnO) were constructed via controlled pyrolysis of ZIF-8 adsorbing different amounts of HAuCl₄·4H₂O. In this pyrolysis process, ZIF-8 was transformed into C-doped ZnO according to the EDX and XPS analysis. Meanwhile, HAuCl₄·4H₂O was transformed into Au nanoparticles that were uniformly dispersed on the surface of C-ZnO as seen in TEM images. The photocatalytic activity of as-prepared catalysts was evaluated by the degradation of methyl orange under UV-vis light irradiation. It was found that the photocatalytic activity of Au/C-ZnO was better than C-ZnO and pure ZnO. Furthermore, Au/C-ZnO exhibited high photocatalytic stability. After three consecutive cycles, there was no noticeable deactivation in the reaction. This unusual photocatalytic activity was attributed to the synergistic effect of C-doping and Au NPs.

C-doped ZnO decorated with Au nanoparticles (Au/C-ZnO) were prepared via one step pyrolysis of ZIF-8 adsorbing HAuCl₄.     

Aqueous synthesis of tin- and indium-doped WO3 films via evaporation-driven deposition and their electrochromic properties

M-doped WO₃ (M = Sn or In) films were prepared from aqueous coating solutions via evaporation-driven deposition during low-speed dip coating. Sn- and In-doping were easily achieved by controlling the chemical composition of simple coating solutions containing only metal salts and water. The crystallinity of the WO₃, Sn-doped WO₃, and In-doped WO₃ films varied with heating temperature, where amorphous and crystalline films were obtained by heating at 200 and 500 °C, respectively. All the amorphous and crystalline films showed an electrochromic response, but good photoelectrochemical stability was observed only for the crystalline samples heated at 500 °C. The crystalline In–WO₃ films exhibited a faster electrochromic color change than the WO₃ or Sn–WO₃ films, and good cycle stability for the electrochromic response in the visible wavelength region.

WO₃ and M-doped WO₃ (M = Sn or In) electrochromic films were obtained from aqueous solutions via evaporation-driven deposition. The In–WO₃ films showed a faster electrochromic response than WO₃ and Sn–WO₃ films, and a good cycle stability.     

A ZnO@ABS/TPU/CaSiO3 3D skeleton and its adsorption/photocatalysis properties for dye contaminant removal

Both adsorption and photocatalysis are considered to be effective methods for removing organic contaminants from dye wastewater. In this study, the construction of 3D skeletons based on the nanoparticles ZnO and ABS/TPU/calcium silicate (CaSiO₃) (shortened as ATC) were fabricated via fused deposition molding (FDM) technology. Characterization by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) depicted that ZnO nanospheres had been successfully grown on the 3D skeleton surface with an enlarged specific surface area. As the results of the RhB adsorption and photocatalytic degradation experiments showed, the removal ratio of RhB onto the ZnO-ATC skeleton was as high as 97.94% and the synergistic effect of adsorption and photocatalysis greatly shortened the RhB degradation time under ultraviolet light irradiation. The nanocomposites synthesized in this study showed a significant removal ability for organic pollutants, and could effectively overcome the limitation of the secondary removal of photocatalysts.

Enhanced synergistic effect of photocatalytic and adsorption was realized through the system constructed of ZnO nanoparticle loaded 3D skeleton.     

Enhanced photocatalytic activity of a visible-light-driven ternary WO3/Ag/Ag3PO4 heterojunction: a discussion on electron transfer mechanisms

WO₃/Ag₃PO₄ with different weight ratios were prepared by ultrasonic assisted two-step deposition method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectroscopy (PL) and transmission electron microscopy (TEM). The photocatalytic activities of all samples were evaluated by the degradation of rhodamine B (RhB) under visible light irradiation. WA-60 shows the highest photocatalytic activity in the WA-x series composite, while the photocatalytic activity of WAA-60 is the best among all samples. The free radical trapping experiments show that photogenerated holes (h⁺) are the main active species. The Ag nanoparticles produced by the decomposition of Ag₃PO₄ are located at the interface of Ag₃PO₄/WO₃, which promotes the separation efficiency of photogenerated electrons and holes. To further explain the photocatalytic mechanism, electrochemical and physical tests are introduced to explore the flow of electrons inside the catalyst.

WO₃/Ag₃PO₄ with different weight ratios were prepared by ultrasonic assisted two-step deposition method.     

Construction of novel Ag/HKUST-1/g-C3N4 towards enhanced photocatalytic activity for the degradation of pollutants under visible light

A novel Ag/metal–organic framework/graphitic carbon nitride (Ag/HKUST-1/g-C₃N₄, AHC) photocatalyst was prepared via an in situ growth strategy and photo-deposition technique for environmental remediation. The as-obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), N₂ adsorption–desorption isotherm measurement, UV-vis diffuse reflection spectroscopy (UV-vis DRS), and photoluminescence (PL) spectroscopy. The results indicated that the hybrids have large surface area, mesoporous structure and enhanced visible-light absorption. The as-prepared hybrid samples exhibited considerable improvement in photocatalytic activity and stability for rhodamine B (RhB) degradation under visible light irradiation (λ > 420 nm). In addition, they also have good adsorption properties. Compared to the pure g-C₃N₄ and Ag/g-C₃N₄, the 5% AHC photocatalyst showed superior photocatalytic activity. Moreover, 5% AHC exhibits good photocatalytic activity even after four cycles. Additionally, the active species trapping and electron spin resonance (ESR) experiments indicated that h⁺ and ·OH were the main active species.

A novel AHC photocatalyst was prepared via in situ growth strategy and photo-deposition technique. The as-prepared hybrid samples have good photocatalytic activity and stability for Rh B degradation under visible-light irradiation.     

Synthesis of vertical WO3 nanoarrays with different morphologies using the same protocol for enhanced photocatalytic and photoelectrocatalytic performances

Tungsten trioxide (WO₃) nanoarrays with different morphologies were successfully synthesized by a hydrothermal method on an FTO substrate. Various nanostructures of WO₃ including nanoflakes, nanoplates, nanoflowers and nanorods were obtained by adjusting only the acidity of the precursor solution. XRD patterns confirmed that the as-prepared orthorhombic WO₃·0.33H₂O transformed to the monoclinic WO₃ phase under annealing at 500 °C. UV-Vis absorbance spectroscopy indicated that the absorption edge of WO₃ nanoflowers exhibited a slight red-shift compared to other morphologies of WO₃. The obtained WO₃ nanoflower arrays exhibit the highest photocurrent density and photocatalytic degradation activity towards methylene blue. Finally, the mechanism of the photocatalytic degradation of methylene blue by WO₃ is discussed.

Hexagonal nanoflower WO₃ arrays were synthesized via a facile hydrothermal method without the assistance of any seed layer or structure directing agent. The nanoflower WO₃ has the highest photocatalytic activity for the degradation of methylene blue.     

Preparation of 1,2-substituted benzimidazoles via a copper-catalyzed three component coupling reaction

1,2-Substituted benzimidazoles were prepared by simply stirring a mixture of copper catalysts, N-substituted o-phenylenediamines, sulfonyl azides and terminal alkynes. Particularly, the intermediate N-sulfonylketenimine occurred with two nucleophilic addition and the sulfonyl group was eliminated via cyclization. In a way, sulfonyl azides and copper catalysts activated the terminal alkynes to synthesize benzimidazoles.

The intermediate N-sulfonylketenimine occurred with two nucleophilic addition, and the sulfonyl group was easily eliminated through cyclization.     

Enhanced visible-light photocatalytic activity and photostability of Ag3PO4/Bi2WO6 heterostructures toward organic pollutant degradation and plasmonic Z-scheme mechanism

Novel Ag₃PO₄/Bi₂WO₆ heterostructured materials with enhanced visible-light catalytic performance were successfully synthesized by assembly combined with a hydrothermal treatment. The microstructures, morphologies, and optical properties of the prepared samples were characterized by multiple techniques. The irregular Ag₃PO₄ nanospheres dispersed on the surface of Bi₂WO₆ nanoflakes, and their catalytic performances were evaluated via the degradation of organic pollutants including rhodamine B (RB), methylene blue (MB), crystal violet (CV), methyl orange (MO), and phenol (Phen) under visible-light irradiation. The resulting Ag₃PO₄/Bi₂WO₆ heterostructured materials displayed higher photocatalytic activity than that of either pure Bi₂WO₆ or Ag₃PO₄. The enhanced photocatalytic activity was due to the good formation of heterostructures, which could not only broaden the spectral response range to visible light but also effectively promoted the charge separation. Meanwhile, the reasonable photoreactive plasmonic Z-scheme mechanism was carefully investigated on the basic of the reactive species scavenging tests, photoelectrochemical experiments, and photoluminescence (PL) spectrum. In addition, the excellent photostability of Ag₃PO₄/Bi₂WO₆ was obtained, which Ag formed at the early photocatalytic reaction acted as the charge transmission-bridge to restrain the further photoreduction of Ag₃PO₄.

Novel Ag₃PO₄/Bi₂WO₆ heterostructured materials were synthesized by assembling Ag₃PO₄ irregular nanospheres on the surface of Bi₂WO₆ nanoflakes and showed superior visible-light photocatalytic activity owing to the good formation of heterostructures.     

Nickel catalyzed intramolecular oxidative coupling: synthesis of 3-aryl benzofurans

Recent research has been focused on the transition metal-catalyzed reactions. Herein we have developed nickel-catalyzed synthesis of 3-aryl benzofurans from ortho-alkenyl phenols via intramolecular dehydrogenative coupling. Notably, simple O₂ gas served as an oxidant, without using any sacrificial hydrogen acceptor. The strategy enabled the synthesis of 3-aryl benzofurans in good to excellent yields.

We have developed nickel-catalyzed synthesis of 3-aryl benzofurans from ortho-alkenyl phenols via intramolecular dehydrogenative coupling. O₂ gas served as an oxidant and 3-aryl benzofurans were synthesized in good to very good yields.