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Skeletal tailoring of two-dimensional π-conjugated polymer (g-C3N4) through sodium salt for solar-light driven photocatalysis
摘要： Structural modi?cation of graphitic carbon nitride (g-C3N4) by addition of sodium salt has been investigated for solar light-driven photocatalysis. The results from optical study indicates that the incorporation of sodium ions decreases band gap energy along with upward shifts of conduction and valence band. However, no substantial increment in surface area was observed, but morphological and optical studies con?rm that the structural deformation of g-C3N4 through sodium salt activates the ?n π * electronic transition, which can extend the absorption range to the red region attributing towards a reduced charge recombination, narrow band gap, and high conduction band edge. Furthermore, the photocatalytic activity of sodium doped g-C3N4 (0.6Na-g-C3N4) was examined under solar light for di?erent operational conditions in terms of phenol degradation of real tannery e?uent, and it was found that under optimum experimental conditions, i.e., 5 h solar irradiance, pH 5, H2O2 concentration 800 mg/L with a ?ow rate of 4 L/h, 0.6 Na- g-C3N4 exhibits 84.22% reduction in phenol while for g-C3N4 only 63.53% was observed.
关键词： Graphitic carbon nitride,Photocatalytic activity,Charge recombination,Solar irradiance,Band gap,Sodium salt
更新于2025-09-23 15:23:52
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Preparation of MoS <sub/>2</sub> @ZnO heterostructure with enhanced photocatalytic activity
摘要： In order to effectively solve environmental problems induced by organic pollutants, the MoS2@ZnO heterostructure is successfully fabricated via a two-step hydrothermal method, in which the MoS2 nanosheets grew on the surface of ZnO nanorods. The synthetic heterostructure is demonstrated to possess excellent photocatalytic activity in the degradation of methylene blue (MB) under ultraviolet (UV) and visible light irradiation. The corresponding photodegradation rate constant of MoS2@ZnO heterostructure reaches up to 0.02075 min-1 and 0.00916 min-1, which are higher than that of pure ZnO (0.00514 min-1 and 0.00048 min-1) under the same reaction conditions. Obviously, compared with pure ZnO, the photocatalytic activity of the MoS2@ZnO heterostructure has been significantly improved. This could be attributed to the increased specific surface area of photocatalyst and the formation of heterostructure between ZnO and MoS2 after loading the MoS2 on the surface of ZnO nanorods. Which help to provide more reaction sites for the adsorption of pollutant and improve the separation efficiency of photogenerated electron-hole pairs.
关键词： MoS2,composite materials,ZnO,photocatalytic activity,heterostructure
更新于2025-09-23 15:22:29
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Hydration accelerator and photocatalyst of nanotitanium dioxide synthesized via surfactant-assisted method in cement mortar
摘要： To develop TiO2-based cement materials, the effect of TiO2 on the cement hydration and photocatalytic reaction should be investigated. The phase, size and shape of TiO2 are important factors for better understanding its application in cement. TiO2 nanoparticles were synthesized by a surfactant-assisted, reverse micelle method to control phase, size and shape by three selected surfactants namely: sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTAB) and TritonX-100. The synthesized TiO2 nanoparticles were characterized by XRD, SEM and TEM for observation of phase, size and shape. The modified micro structures of admixed cements with the different synthesized TiO2 nanoparticles incorporated were also examined by SEM. Particularly, the hydration process and photocatalytic reaction of the cement mixture were evaluated by heat flow calorimetry and methylene blue (MB) degradation, respectively. Results showed that anatase-rich and smaller size TiO2 nanoparticles provided accelerated cement hydration and the ability to degrade MB photocatalytically at the surface of admixed-TiO2 cement.
关键词： Surfactant-assisted method,Photocatalytic activity,Hydration,Cement,Titanium dioxide nanoparticle
更新于2025-09-23 15:22:29
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The microstructure and optical property of Na-doped ZnO system by sol-gel method
摘要： Pure and Na-doped ZnO (2 at.%, 5 at.% and 10 at.%) films are synthesized by sol-gel method and annealed at 500 °C for 4 h. The as-synthesized nanoparticles are characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) with energy dispersive X-ray spectroscopy (EDS). The samples exhibited hexagonal ZnO lattice structure and another Na2O2 phase was detected in the 5 at.% Na-doped ZnO sample. The calculated average crystalline size increases from 42.0 nm to 43.5 nm when Na content increased from 0 to 10 at.%. FESEM and TEM analysis identifies that the average size of the Na-doped ZnO nanoparticles lies in between 50 nm and they appear in spheroid-like or rod-like shape. The transmittance of the sample was above 80% and the results of photocatalytic activity show that Na-doped ZnO nanoparticles exhibit higher photodegradation activity (about 91%) than pure ZnO nanoparticles under UV irradiation.
关键词： microstructure,Na-doped,photocatalytic activity.,transparent property,ZnO
更新于2025-09-23 15:22:29
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Data on the convenient fabrication of carbon doped WO3? ultrathin nanosheets for photocatalytic aerobic oxidation of amines at room temperature
摘要： The oxidation of amines to imines is an important chemical transformation. In this article, we report original data on the synthesis of carbon doped WO3 (cid:1) x ultrathin nanosheets via an acid-assisted one-pot process, which exhibit excellent photocatalytic activity in the aerobic oxidation of amines to corresponding imines under visible light irradiation at room temperature. The composition, microstructure, morphology, photocatalytic activity of the corresponding samples and possible mechanism are included here.
关键词： Ultrathin nano-sheet,Photocatalytic activity,Aerobic oxidation
更新于2025-09-23 15:22:29
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Effect of pH on the Properties of BiVO<sub>4</sub> by Hydrothermal Synthesis Method
摘要： Bismuth vanadate (BiVO4 ) powders were synthesized using Bi(NO3)3.5H2O and NH4VO3 as raw materials, NaOH and HNO3 for pH adjustment. The samples were characterized by X-ray diffraction ( XRD ), scanning electron microscopy (SEM ) and UV-vis diffuse reflectance spectra techniques. The results show that the pH of precursor solution has great effect on the composition and morphology of products. Synthetic product was BiVO4 with two kinds of crystal shape ( monoclinic and tetragonal ) with pH of 3; synthetic product was pure monoclinic phase BiVO4 when the pH is between 5-9. Whereas, V2O5 and Bi2O3 appeared when the pH was 11; synthetic product was a mixture of V2O5 and Bi2O3 with pH of 13, and BiVO4 didn’t exist. The photocatalytic activity was evaluated by the degradation of methylene blue solution. It is shown that the synthetic sample has the best photocatalytic ability with pH of 5. The degradation of methylene blue reaches 84.7% when irradiated for 240 min by high pressure mercury lamp, and the sample synthesized at 13 for pH has strong adsorption capacity and poor photocatalytic ability.
关键词： Bismuth vanadate,Photocatalytic activity,pH value,Hydrothermal synthesis
更新于2025-09-23 15:22:29
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The Effects of the Content of NiO on the Microstructure and Photocatalytic Activity of the NiO/TiO2 Composite Film
摘要： The NiO/TiO2 composite films with the NiO content of 3 %, 5 %, 10 %, 13 %, 15 % and 20 % were prepared by mechanical coating technology and subsequent oxidation process. The composition and microstructure of the films were analyzed by X-ray Diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS). The photocatalytic activity was evaluated and the effects of the content of NiO on microstructure and photocatalytic activity of the films were studied. The results show that NiO particles are dispersed in the Ti coatings, and the NiO concentration in the inner layer of the coatings is higher than in the outer layer. With the addition of NiO in the NiO/Ti coating, the ductility is deteriorated and the thickness is reduced of the NiO/Ti coatings. The films with NiO/TiO2/Ti composite microstructure are obtained by the oxidation of NiO/Ti coatings. Photocatalytic efficiency of the films is obviously enhanced with the help of the p-n junction heterostructure in the NiO/TiO2 films. The optimum content of NiO is about 13 %, and the degradation rate of methyl orange solution reaches the maximum value of 88.44 %.
关键词： mechanical coating technology,NiO content,photocatalytic activity,NiO/TiO2 composite films
更新于2025-09-23 15:22:29
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A novel bi-functional SiO2@TiO2/CDs nanocomposite with yolk-shell structure as both efficient SERS substrate and photocatalyst
摘要： A novel multi-functional yolk-shell SiO2@TiO2/CDs(y-STCs) nanocomposite with interesting structure of SiO2 cores, porous TiO2 shell, and cavities was synthesized by using a simple method. The experimental results indicate that the yolk-shell structure and modification of carbon dots (CDs) play important roles in the enhancement of SERS signals and photocatalytic performance. The y-STCs nanocomposite used as the SERS substrate showed excellent efficiency and reproducibility for the detection of rhodamine 6G (R6G). The detection limit of R6G was shown to be as low as 6 × 10?8 M. Furthermore, the fabricated y-STCs nanocomposite utilized as the photocatalytst for the degradation of dinitraphenols (DNP) can greatly shorten reaction time to 120 min compared with previous studies, and the DNP degradation rate could reach 96% under simulated sunlight irradiation. The y-STCs nanospheres also possessed excellent cycle stability for the photocatalytic degradation of DNP. Thus, the bi-functional y-STCs nanocomposite may have potential applications in the detection and photocatalytic degradation of organic pollutants.
关键词： SiO2@TiO2/CDs nanocomposite,Yolk-shell structure,SERS detection,Photocatalytic activity
更新于2025-09-23 15:22:29
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Gaseous bubble-assisted in-situ construction of worm-like porous g-C3N4 with superior visible light photocatalytic performance
摘要： Metal-free graphitic carbon nitride (g-C3N4) displays benign photocatalytic properties for contaminants photodegradation under visible photoirradiation. Devising a simple modification strategy for the improved photocatalytic activity of g-C3N4 has always been desired. Herein, we report a spherical worm-like g-C3N4 nanostructure via facile ammonium lauryl sulfate (ALS) gaseous bubbles templating approach. This strategy employing ALS as gaseous bubbles templating agent bestowed not only g-C3N4 with improved specific surface areas, a porous structure with more exposed photocatalytic reactive sites and mass diffusion of reactants molecules, but also rendered extended optical absorption range and suppression of the photoinduced charge carriers recombination. As a result, the ALS-mediated g-C3N4 photocatalysts unfolded excellent photocatalytic performance regarding photodegradation of rhodamine B (RhB) and phenol under visible photoirradiation. Additionally, the quenching effects of various scavengers proved that the holes (h+) and superoxide anions (?O2-) radicals were the main active species responsible for ameliorated photocatalytic performance for rhodamine B and phenol photodegradation. Our work offers a straightforward approach for developing high-performance metal free photocatalysts with great potential for environmental remediation.
关键词： Ammonium lauryl sulphate,g-C3N4,Photocatalytic activity,Porous,Gaseous bubbles
更新于2025-09-23 15:22:29
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Construction of Ag@AgCl decorated TiO2 nanorod array film with optimized photoelectrochemical and photocatalytic performance
摘要： A novel Ag@AgCl/TNR film photocatalyst was successfully obtained by a facile multistep route. Using a well-organized TiO2 nanorod array (TNR) film as the starting material, Ag nanoparticles were uniformly deposited on the TNR film via a photochemical reduction, and in situ oxidation of Ag by FeCl3 solution resulted in the formation of Ag@AgCl/TNR film. The structure, morphology, composition, optical, photocatalytic and photoelectrochemical properties of the obtained films were investigated in detail. The results showed that core-shell Ag@AgCl can effectively promote the transfer of photo-generated electron-hole pairs, suppress their recombination, and enhance the visible light absorption. The Ag@AgCl/TNR film with 60 min oxidation time (S60) showed the highest photocurrent and best transfer performance of interfacial electrons in the electrochemical impedance spectroscopy (EIS) Nyquist plots. For the photodegradation of methyl orange (MO), the S60 exhibited the highest photocatalytic efficiency (90.8%) and good stability under visible light irradiation, which can be comparable and even better than the previous reports. A detailed photocatalytic mechanism was proposed on the basis of the fact that Ag nanoparticles with surface plasma resonance (SPR) can be excited by visible light and this unique structure effectively transfers photo-generated electrons from Ag to TiO2 conduction band, accomplished by the transfer of compensative electrons from a donor (Cl-) to Ag nanoparticles.
关键词： Nanorod array,Photocatalytic activity,Photocurrent,TiO2,Ag@AgCl
更新于2025-09-23 15:22:29