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Synthesis of highly crystalline photocatalysts based on TiO2 and ZnO for the degradation of organic impurities under visible-light irradiation
摘要： A TiO2–ZnO binary oxide system (with molar ratio TiO2:ZnO = 8:2) was synthesized by a hydrothermal method, assisted by calcination at temperatures of 500, 600 and 700 °C, using zinc citrate as the precursor of ZnO. The morphology (SEM, TEM), crystalline structure (XRD, Raman spectroscopy), diffuse reflectance spectra (DRS), chemical surface composition (EDXRF), porous structure parameters (low-temperature N2 sorption) and characteristic functional groups (FT-IR) of the TiO2–ZnO oxide materials were comprehensively analyzed. The novelty of this work is the observation of the coexistence of the crystalline structures of anatase and ZnTiO3 in TiO2–ZnO oxide materials. Moreover, it is shown that the obtained materials absorb visible radiation. The key stage of the study was the evaluation of the photocatalytic activity of the TiO2–ZnO binary oxide systems in the degradation of model organic pollutants: C.I. Basic Red 1, C.I. Basic Violet 10, C.I. Basic Blue 3 and 4-nitrophenol. For all synthesized materials, a high efficiency of degradation of the model organic impurities was demonstrated. The results show that the synthesized products may be materials of interest for use in the degradation of organic pollutants. Moreover, the kinetics of the photocatalytic degradation of selected organic compounds were determined based on the Langmuir–Hinshelwood equation, assuming a pseudo-first-order (PFO) reaction.
关键词： Titania,Zinc oxide,Photocatalysis,Binary oxide systems,Hydrothermal synthesis
更新于2025-09-19 17:15:36
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Electrophoresis Assembly of Novel Superhydrophobic Molybdenum Trioxide (MoO3) Films with Great Stability
摘要： This work presents a hydrothermal synthesis approach to produce novel schistose molybdenum trioxide (MoO3) powders with wide application, and introduces a facile electrophoresis assembly technique to construct the superhydrophobic MoO3 films (SMFs) with contact angle up to 169 ± 1° at normal pressure and temperature. The microstructures and chemical compositions of product were analyzed by field emission scanning electron microcopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD). The wettability and stability studies indicate that the SMFs all show great resistance in various environments with adjusting factors, including droplets with different surface tension, pH, relative humidity, etc., and the stability can be maintained at least for five months. Notably, this paper will provides a valuable reference for designing novel oxide powders and their high-efficient hydrophobic film formation with self-cleaning or water proof properties.
关键词： superhydrophobic stability,Hydrothermal synthesis,Electrophoretic deposition,Schistose molybdenum trioxide,high-efficient
更新于2025-09-19 17:15:36
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Structural, morphological and 6 MeV energy electron dosimetric properties of Cu doped SnO<sub>2</sub> phosphor.
摘要： Cu doped SnO2 (SnO2:Cu) nano phosphor (NP) was successfully synthesized by one-step simple hydrothermal method and it was characterized by XRD (X-Ray Diffraction) for structural, FESEM (Field Emission Scanning Electron Microscopy) for morphological and EDS (Electron Dispersive Spectroscopy) for elemental analysis. NP was annealed at 700 °C for 2 hr and its crystallinity for tetragonal phase was confirmed through XRD. The crystallite size was ~10.39 nm for un-annealed and ~18.16 nm for annealed samples which has been calculated using Scherer equation. The particle size was estimated to be ~43 nm and the elemental composition of Sn, O, Cu was obtained by EDS. In addition, to study the dosimetric properties, the SnO2:Cu phosphors were irradiated with 6 MeV electron beam at fluences ranging from 10 x 10^11 e/cm^2 to 20 x 10^12 e/cm^2 which is equivalent to the 1.55 kGy to 31 kGy. The irradiated sample showed Thermoluminescence (TL) dosimetric glow peaks at 170 °C, 263 °C and 303 °C. SnO2:Cu NP was found to be sensitive enough for energetic electrons. Further, it has been noticed that the TL dose response found sensitive upto 10 x 10^12 e/cm^2 (15.50 kGy) with fading of 5.1 % for 2 months. Hence, SnO2:Cu can be used for the measurement of electron doses.
关键词： Hydrothermal Method,Electron Irradiation,Thermoluminescence,SnO2
更新于2025-09-19 17:15:36
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One dimensional hierarchical BiOCl microrods: their synthesis and their photocatalytic performance
摘要： In this work, one dimensional hierarchical BiOCl microrods were controllably synthesized via a hydrothermal method using sodium citrate as the structure-directing agent. Each hierarchical BiOCl structure is made up of many BiOCl nanosheets in which the size and thickness are controlled by the concentration of sodium citrate. The high-resolution transmission electron microscopy (HRTEM) measurements show that each nanosheet consists of the BiOCl hierarchical structure with exposed (001) (top surface) and (110) (side surface) facets. With the amount of sodium citrate increasing, the ratio (110)/(001) gradually increases. These hierarchical BiOCl architectures exhibit a more outstanding photocatalytic activity than BiOCl nanosheets with exposed (001) facets, and rhodamine B (RhB) and methyl orange (MO) can be degraded in 3 and 4 min, respectively. This enhanced photocatalytic performance is ascribed to the fast separation and transfer of photogenerated electron–hole pairs, the formation of hierarchical architectures and the large BET surface areas. Radical scavenger experiments indicate that holes (h+) and superoxide radicals (˙O2?) are the main active species for MO degradation during the photocatalytic process.
关键词： BiOCl,hydrothermal synthesis,photocatalytic activity,hierarchical structure,sodium citrate
更新于2025-09-19 17:15:36
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Cation-tuned synthesis of the A <sub/>2</sub> SO <sub/>4</sub> ·SbF <sub/>3</sub> (A = Na <sup>+</sup> , NH <sub/>4</sub><sup>+</sup> , K <sup>+</sup> , Rb <sup>+</sup> ) family with nonlinear optical properties
摘要： Four antimony fluoride sulfates named A2SO4·SbF3 (A = Na+, NH4+, K+, Rb+) have been successfully synthesized using a hydrothermal method by introducing Sb3+ cations with a stereochemically active lone pair in sulfates and subsequently tuning the structure through the second monovalent cations. All of the title compounds are stoichiometrically equivalent materials which share a common structural motif composed of a distorted SO4 tetrahedron and an asymmetric SbF3 polyhedron. However, the macroscopic centricities of these four compounds are significantly influenced by the size and coordination environment of cations; Na2SO4·SbF3 crystallizes in centrosymmetric space groups Cmca and (NH4)2SO4·SbF3 in Pbca, while K2SO4·SbF3 and Rb2SO4·SbF3 crystallizes in noncentrosymmetric space group P212121. Complete characterization including thermal analyses, infrared and UV-vis spectroscopy, and theoretical calculations is also reported. Powder second harmonic generation measurement for noncentrosymmetric K2SO4·SbF3 and Rb2SO4·SbF3 indicated that both of them are type I phase-matchable.
关键词： hydrothermal synthesis,cation tuning,nonlinear optical materials,antimony fluoride sulfates,second harmonic generation
更新于2025-09-19 17:15:36
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Boosting the Yield of MXene 2D Sheets via a Facile Hydrothermal-Assisted Intercalation
摘要： Ti3C2Tx (MXene) exhibits attractive properties in different applications. However, traditional synthesis leads to unsatisfactory yield of two-dimensional (2D) Ti3C2Tx, e.g. lower than 20%, which stems from the strong interactions of potential Ti-Ti bonds and residual Ti-Al bonds between the adjacent Ti3C2 layers, hindering the effective intercalation and delamination. Herein, we propose a facile hydrothermal-assisted intercalation (HAI) strategy to boost the yield of 2D sheets, achieving a record high value of 74%. This HAI assists the diffusion and intercalation of reagent effectively, promoting the subsequent delamination; meanwhile, antioxidant is applied to protect these Ti3C2Tx from oxidation during HAI process. Therefore, massive Ti3C2Tx 2D sheets can be easily synthesized. Thanks to the synergistic effect of high conductivity and substantial terminated functionalities, these Ti3C2Tx 2D sheets show promising application in supercapacitor, providing a high capacitance of 482 F g-1. Besides, the ultrafast carrier dynamics results of Ti3C2Tx 2D sheets clearly imply the promising application in photocatalysis, due to the relatively long bleaching relaxation time. Our work not only paves the way for the mass production of Ti3C2Tx 2D sheets, but also provides insights into their electronic and optical properties.
关键词： facile,Hydrothermal-assisted intercalation (HAI),high yield,MXene,Ti3C2Tx
更新于2025-09-19 17:15:36
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Nitrogen-doped carbon nanodots prepared from polyethylenimine for fluorometric determination of salivary uric acid
摘要： Stable and low-cost carbon dots (C-dots) were prepared from polyethylenimine (PEI) by a hydrothermal method. It is found that the fluorescence of the C-dots (best measured at excitation/emission wavelengths of 365/473 nm) is quenched by selective oxidation of surface PEI by periodate but recovers in the presence of uric acid (UA). It is assumed that this is due to the selective reduction of the nitrone groups to hydroxylamine groups by UA. The findings were used to design a fluorometric method for determination of UA that has a 2.3 nM detection limit. This is lower than that of reported fluorometric and enzymatic assays. The performance of the method has been validated by determination of UA in samples of human saliva. It is found that the results agree well with those obtained by a commercial UA assay.
关键词： Periodate,C-dots,Antioxidant,Nitrone,Hydrothermal synthesis,Uricase
更新于2025-09-19 17:15:36
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Hydrothermal Synthesis and Luminescent Properties of Spindle-Like NaGd(MoO <sub/>4</sub> ) <sub/>2</sub> :Eu <sup>3+</sup> Phosphors
摘要： Spindle-like NaGd(MoO4)2: Eu3 + phosphors with various Eu3 + concentrations were prepared via a hydrothermal process and characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The XRD results suggested that the prepared samples had a scheelite structure. The FE-SEM images indicated that the prepared NaGd(MoO4)2: Eu3 + phosphors were spindle-like. The influences of the ratio of sodium citrate and the rare earth cations on the product were studied. It was found that sodium citrate, as the chelating agent, could significantly influence the structure and morphology of the samples. The emission spectra, excitation spectra, fluorescence decay curves, and quantum yields of the samples were measured. The luminescent properties of the materials were studied. The results indicated that the electron–phonon coupling between the Eu3 + and the NaGd(MoO4)2 host was weak, and with the increase of the Eu3 + concentration, the Huang–Rhys factor increased. Additionally, the quantum efficiency of the Eu3 + 5D0 level was calculated, and it was found that the quantum efficiency decreased with the increase of the Eu3 + concentration.
关键词： Electron-phonon coupling,Rare earth,Hydrothermal,Molybdate,Luminescence
更新于2025-09-19 17:15:36
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An urchin-like SnO2/NaNbO3 nanocomposite with stable humidity-sensing properties at room temperature
摘要： An urchin-like nano-composite of SnO2/NaNbO3 was fabricated by the hydrothermal method and the influence of the Sn/Nb ratio in the samples on their humidity-sensing properties was investigated. The phases and morphologies of these composites and their elemental distributions were analyzed by X-ray diffraction scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The sensor based on the optimum Sn/Nb ratio of 1:0.4 exhibited remarkable humidity-sensing properties, including a good response (S = 4823.8) that was 8.72 times higher than that of the pure SnO2 sensor (S = 553.01). The composites showed rapid response and recovery times (3/9 s), as well as good stability, linearity, and excellent selectivity. The fabrication and humidity-sensing mechanisms were systematically analyzed using analog computations and Nyquist diagrams, respectively. Compared with pure NaNbO3 and SnO2 sensors, our easily prepared SnO2/NaNbO3 sensor demonstrates good sensing properties and holds great promise for use in humidity-sensing applications.
关键词： Humidity,SnO2,Urchin-like structure,NaNbO3,Hydrothermal method
更新于2025-09-19 17:15:36
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Synthesis and Characterization of a Rare Transition-Metal Oxothiostannate and Investigation of Its Photocatalytic Properties
摘要： The new transition-metal oxothiostannate [Ni(cyclen)(H2O)2]4[Sn10S20O4]·～13H2O (1) was prepared under hydrothermal conditions using Na4SnS4·14H2O as the precursor in the presence of [Ni(cyclen)(H2O)2](ClO4)2·H2O. Compound 1 comprises the [Sn10S20O4]8? anion constructed by the T3-type supertetrahedron [Sn10S20] and the [Sn10O4] anti-T2 cluster. Channels host the H2O molecules, and the sample can be reversibly dehydrated and rehydrated without significantly affecting the crystallinity of the material. 119Sn NMR spectroscopy of an aqueous solution of Na4SnS4·14H2O evidences that between 25 and 120 °C only [SnS4]4? and [Sn2S6]4? anions are present. In further experiments, hints were found that the formation of the tin oxosulfide ions depends on the Ni2+-centered complexes. Compound 1 exhibits promising photocatalytic properties for the visible-light-driven hydrogen evolution reaction, with 18.7 mmol·g?1 H2 being evolved after 3 h.
关键词： photocatalytic hydrogen evolution,oxothiostannate,NMR spectroscopy,hydrothermal synthesis,transition-metal complex
更新于2025-09-19 17:15:36