Hierarchical assembly of highly efficient visible-light-driven Ag/g-C_(3)N_(4)/kaolinite composite photocatalyst for the degradation of ibuprofen

A novel Ag/g-C_(3)N_(4)/kaolinite composite photocatalyst was fabricated for the first time through a two-step assembly strategy by employing in situ calcination and a photodeposition process.The synthesized Ag/g-C_(3)N_(4)/kaolinite composite reached a higher degradation rate of ibuprofen(IBP)with a reaction rate constant of 0.0113 min^(-1) at an Ag content of 7% under visible-light irradiation,which was approximately 1.87 times that of the Ag/g-C_(3)N_(4) composite.Based on the physicochemical properties,the enhanced photocatalytic activity was attributed to the stronger adsorption property,wider photoresponse range and more efficient separation and transfer of electron-hole pairs.Furthermore,the incorporation of monodispersed Ag nanoparticles onto the g-C_(3)N_(4)/kaolinite sheets provided more reactive sites for the IBP degradation.In addition,according to the EPR study and trapping experiments,it was demonstrated that holes(h^(+))should be the key reactive species.A possible pathway of IBP degradation was also proposed based on the detected intermediates.Overall,the results of this work may facilitate the design of a novel visible-light-driven photocatalyst with a high efficiency that is derived from a natural mineral for environmental remediation.

Hydrothermal fabrication and visible-light-driven photocatalytic properties of bismuth vanadate with multiple morphologies and/or porous structures for Methyl Orange degradation

Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy. The materials were characterized by means of the XRD, Raman, TGA/DSC, SEM, XPS, and UV-Vis techniques. The photocatalytic activities of the BiVO4 materials were evaluated for the degradation of Methyl Orange under visible-light irradiation. It is observed that pH value and surfactant exerted a great effect on the morphology and pore structure of the BiVO4 product. Spherical BiVO4 with porous structures, flower-cluster-like BiVO4, and flower-bundle-like BiVO4 were generated hydrothermally at 100°C with poly（vinyl pyrrolidone） （PVP） and urea （pH = 2） and at 160°C with NaHCO3 （pH = 7 and 8）, respectively. The PVP-derived BiVO4 showed much higher surface areas （5.0-8.4 m2/g） and narrower bandgap energies （2.45-2.49 eV）. The best photocatalytic performance of the spherical BiVO4 material with a surface area of 8.4 m2/g was associated with its higher surface area, narrower bandgap energy, higher surface oxygen vacancy density, and unique porous architecture.

Visible-light-driven Cadogan reaction

Visible-light-driven photochemical Cadogan-type cyclization has been discovered.The organic D-A type photosensitizer 4 CzIPN found to be an efficient mediator to transfer energy from photons to the transient intermediate that breaks the barriers of deoxygenation in Cadogan reaction and enables a mild metalfree access to carbazoles and related heterocycles.DFT calculation results indicate mildly endergonic formation of the intermediate complex of nitrobiarenes and PPh3,which corresponds with experimental findings regarding reaction temperature.The robust synthetic capacity of the photoredox Cadogan reaction systems has been demonstrated by the viable productivity of a broad range of carbazoles and related N-heterocycles with good tolerance of various functionalities.

Present and Future of Phase‑Selectively Disordered Blue TiO2 for Energy and Society Sustainability

Titanium dioxide(TiO2)has garnered attention for its promising photocatalytic activity,energy storage capability,low cost,high chemical stability,and nontoxicity.However,conventional TiO2 has low energy harvesting efficiency and charge separation ability,though the recently developed black TiO2 formed under high temperature or pressure has achieved elevated performance.The phase-selectively ordered/disordered blue TiO2(BTO),which has visible-light absorption and efficient exciton disassociation,can be formed under normal pressure and temperature(NPT)conditions.This perspective article first discusses TiO2 materials development milestones and insights of the BTO structure and construction mechanism.Then,current applications of BTO and potential extensions are summarized and suggested,respectively,including hydrogen(H2)production,carbon dioxide(CO2)and nitrogen(N2)reduction,pollutant degradation,microbial disinfection,and energy storage.Last,future research prospects are proposed for BTO to advance energy and environmental sustainability by exploiting different strategies and aspects.The unique NPT-synthesized BTO can offer more societally beneficial applications if its potential is fully explored by the research community.

Ultrasonic-assisted synthesis of plasmonic Z-scheme Ag/AgCl/WO_3-nanoflakes photocatalyst in geothermal water with enhanced visible-light photocatalytic performance

In this study, the Ag/Ag Cl/WO3 plasmonic Z-scheme photocatalysts with different contents of Ag/Ag Cl nanoparticles（NPs） were prepared through a facile ultrasonic precipitation method in geothermal water,wherein the geothermal water served as the chlorine source. Then the photocatalytic activity was investigated by degradation of 4-Aminobenzoic acid（4-ABA） under visible-light irradiation. It was found that the as-prepared 50 wt% Ag/Ag Cl/WO3 photocatalyst showed the highest photocatalytic efficiency with 25.12 and 3.53 times higher than those of pure WO3 and Ag/Ag Cl, respectively. The active species trapping experiments indicated that h＋and ·O2-were key factors in 4-ABA photodegradation process. The possible plasmonic Z-scheme photocatalytic mechanism of photocatalytic reaction for 4-ABA degradation was proposed based on systematical characterizations. We hope this paper could give new ideas for further exploiting geothermal energy to design and fabricate highly efficient visible-light-driven photocatalysts for environmental remediation.

Synthesis of Porous Hollow Micro spheres of BiVO_4 Based on EDTA and SDBS via Hydro thermal Method

Porous hollow microspheres of bismuth vanadate(BiVO_4) were successfully synthesized with the assistances of ethylenediamine tetraacetic(EDTA) and sodium dodecylbenzene sulfonate(SDBS) via hydrothermal method.The as-prepared BiVO_4 samples were characterized by X-ray diffraction(XRD),field-emission scanning electron microscopy(FE-SEM) and UV-vis diffuse reflectance spectra(DRS).It was found that the ratio of EDTA and SDBS had a significant impact on the crystalline structure,size and morphology of BiVO_4 photocatalyst.The crystal phase could be adjusted by changing the mass ratio of EDTA and SDBS.The photocatalytic activities of different BiVO_4 samples were investigated through the degradation of RhB in the presence of H_2O_2 under visible light irradiation.The results indicated that the photocatalytic performance of the BiVO_4 microstructures was greatly influenced by the porous structure,morphology and band gap.The BiVO_4 sample prepared with the EDTA and SDBS ratio of 2:1 and total amount of 1.5 g have shown superior photocatalytic performance for its unique morphology,good porous structure and low band gap energy.

Mass Production of Bi3NbO7/Bi2Zn(2/3)Nb(4/3)O7 Composites and Their Visible-light Photocatalytic Activity

Series Bi3NbO7/Bi2Zn（2/3）Nb（4/3）O7 （BN/BZN） composites were synthesized through a facile solid state reaction method. The products were characterized by X-ray diffraction（XRD）, field emission scanning electron microscopy（FE-SEM） and UV-vis diffuse reflectance spectroscopy（DRS）. When BN： BZN=0.1 mole ratio, the BN/BZN composite showed the best visible-light-driven photocatalytic performance, which decomposed nearly 100% of Rh B（10 ppm, p H=3-4） within 40 min. The results demonstrated that in-situ solid state synthesis of BN/BZN composites could be an efficient strategy to develop new photocatalyst for environmental remediation.

Porous FeO_x/BiVO_(4-δ)S_(0.08): Highly efcient photocatalysts for the degradation of Methylene Blue under visible-light illumination

Porous S-doped bismuth vanadate with an olive-like morphology and its supported iron oxide （y wt.% FeOx/BiVO4-δS0.08, y = 0.06, 0.76, and 1.40） photocatalysts were fabricated using the dodecylamine-assisted alcohol-hydrothermal and incipient wetness impregnation methods, respectively. It is shown that the y wt.% FeOx/BiVO4-δS0.08 photocatalysts contained a monoclinic scheetlite BiVO4 phase with a porous olive-like morphology, a surface area of 8.8-9.2 m^2/g, and a bandgap energy of 2.38-2.42 eV. There was co-presence of surface Bi^5＋, Bi^3＋, V^5＋, V^3＋, Fe^3＋, and Fe^2＋ species in y wt.% FeOx/BiVO4-δS0.08. The 1.40 wt.% FeOx/BiVO4-δS0.08 sample performed the best for Methylene Blue degradation under visible-light illumination. The photocatalytic mechanism was also discussed. We believe that the sulfur and FeOx co-doping, higher oxygen adspecies concentration, and lower baudgap energy were responsible for the excellent visible-light-driven catalytic activity of 1.40 wt.% FeOx/BiVO4-δS0.08.

One-pot hydrothermal fabrication of BiVO_(4)/Fe_(3)O_(4)/rGO composite photocatalyst for the simulated solar light-driven degradation of Rhodamine B

Fabrication of easily recyclable photocatalyst with excellent photocatalytic activity for degradation of organic pollutants in wastewater is highly desirable for practical application.In this study,a novel ternary magnetic photocatalyst BiVO_(4)/Fe_(3)O_(4)/reduced graphene oxide(BiVO_(4)/Fe_(3)O_(4)/rGO)was synthesized via a facile hydrothermal strategy.The BiVO_(4)/Fe_(3)O_(4) with 0.5 wt%of rGO(BiVO_(4)/Fe_(3)O_(4)/0.5%rGO)exhibited superior activity,degrading greater than 99%Rhodamine B(RhB)after 120 min solar light radiation.The surface morphology and chemical composition of BiVO_(4)/Fe_(3)O_(4)/rGO were studied by scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,UV–visible diffuse reflectance spectroscopy,Fourier transform infrared spectroscopy,and Raman spectroscopy.The free radicals scavenging experiments demonstrated that hole(h^(+))and superoxide radical(O_(2)•^(−))were the dominant species for RhB degradation over BiVO_(4)/Fe_(3)O_(4)/rGO under solar light.The reusability of this composite catalyst was also investigated after five successive runs under an external magnetic field.The BiVO_(4)/Fe_(3)O_(4)/rGO composite was easily separated,and the recycled catalyst retained high photocatalytic activity.This study demonstrates that catalyst BiVO_(4)/Fe_(3)O_(4)/rGO possessed high dye removal efficiency in water treatment with excellent recyclability from water after use.The current study provides a possibility for more practical and sustainable photocatalytic process.

Efficient Photogeneration of Hydrogen Boosted by Long-Lived Dye-Modified Ir(III)Photosensitizers and Polyoxometalate Catalyst

Developing efficient catalysts and photosensitizers is crucial for the construction of effective photocatalytic H2-evolving systems.Here,we report the facile preparation of Coumarin-modified Ir(III)complexes(PS-2 and PS-3)and their utilization as chromophores to drive favorable photocatalytic H2 evolution using Ni-substituted polyoxometalate(Ni_(3)PW_(10))catalyst and triethanolamine(TEOA)as an electron donor.Compared with the commercially available unmodified Ir(III)complex(PS-1),both PS-2 and PS-3 displayed intensive absorption in the range of 400–550 nm with ε_(max) of 110,620 and 91,430 M^(−1) cm6(−1),respectively.Varying the substitutes on the bipyridine ligand affected their physicochemical properties and the corresponding photocatalytic activity dramatically.Under photocatalytic conditions,the quantity of H2 molecules generated by PS-2-and PS-3-containing systems were 13.1 and 2.1 times,respectively,that of the PS-1-containing system.When PS-2 was used as a photosensitizer,the highest turnover number(TON)of 19,739 was obtained versus Ni_(3)PW_(10) catalyst.Various spectroscopic and computational studies have revealed that factors such as strong and broad visible-light-absorbing ability,long-lived triplet state,suitable redox potential,opposed by using polyoxometalate(POM)catalyst,and large highest occupied molecular orbital(HOMO)–lowest unoccupied molecular orbital(LUMO)gap of PS-2 attributed to drastically enhanced photocatalytic activity.

Fabrication of AQ2S/GR composite photosensitizer for the simulated solar light-driven degradation of sulfapyridine

Chlorination has been intensively investigated for use in water disinfection and pollutant elimination due to its efficacy and convenience;however,the generation and transportation of chlorine and hypochlorite are energy-consuming and complicated.In this study,a novel binary photosensitizer consisting of anthraquinone-2-sulfonate(AQ2S)and graphene was synthesized via a p-p stack adsorption method;this compound could allow for the chlorination of organic pollutants using on-site chlorine generation.In this photosensitive degradation process,sulfapyridine(SPY)was selected as a model pollutant and was decomposed by the reactive species(Cl2
-,Cl
and O2
-)generated during the photosensitive oxidation of chloride.The synthesized AQ2S/graphene exhibited superior activity,and the degradation rate of SPY was over 90%after 12 h of visible light irradiation with a kinetic constant of 0.2034h1.Results show that 20 mg AQ2S/GR at a 21%weight percentage of AQ2S in a pH 7 SPY solution with 1 mol/L Clachieved the highest kinetics rate at 0.353 h1.Free radical trapping experiments demonstrated that Cl2
-and O2
-were the dominant species involved in SPY decomposition under solar light.The reusability and stability of this composite were verified by conducting a cycle experiment over five successive runs.The capacity of photodegradation still remained over 90%after these 5 runs.The current study provides an energyefficient and simple-operational approach for water phase SPY control.