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- 2019
- 2018
- electropolymerization
- polyporphyrin films
- quartz crystal microbalance method
- oxygen electroreduction.
- supercontinuum generation
- Nonlinear
- photonic crystal fiber taper
- Applied Chemistry
- Optoelectronic Information Science and Engineering
- Beijing University of Posts and Telecommunications (BUPT)
- G.A. Krestov Institute of Solution Chemistry of RAS
- University Union Nicola Tesla
- Ivanovo State University of Chemistry and Technology
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Bismuth vanadate single crystal particles modified with tungsten for efficient photoeletrochemical water oxidation
摘要： Highly efficient water oxidation utilizing visible light is a crucial step in water splitting. Bismuth vanadate (BiVO4) single crystal particles have attracted much attention in water oxidation recently, owing to their outstanding physicochemical properties and exposed active facets. The performance of BiVO4 single crystal particles is generally hindered by their poor conductivity and worse charge separation. Doping BiVO4 single crystal particles with other metal elements has been considered as an efficient way to improve their conductivity, charge separation and performance. However, there are few successful reports, because structure and morphology of BiVO4 single crystal particles are easily changed by addition of impurities. Here, we present that W doped BiVO4 crystal particles were successfully achieved by developing a simple impregnation method following with a high temperature annealing process. The obtained W-BiVO4 single crystal particles exhibited improved conductivity, carrier density and thereby enhanced activity for water oxidation. The solar energy conversion of the W-BiVO4 electrode was doubled compared with the pristine one. Thus, this work opens an avenue for developing efficient single crystal particle photocatalysts.
关键词： BiVO4,Tungsten,Single crystal particles,Water oxidation
更新于2025-11-19 16:51:07
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An Insight into the Mechanisms of the Scale Inhibition. A Case Study of a Novel Task-specific Fluorescent-tagged Scale Inhibitor Location on Gypsum Crystals
摘要： Scaling in reverse osmosis facilities, boilers, heat exchangers, evaporation plants, and oilfield applications is a serious problem worldwide. In order to provide a new insight into the mechanism of the scale formation and inhibition, a novel fluorescent-tagged 1-hydroxy-7-(6-methoxy-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)heptane-1,1-diyl-di(phosphonic acid), (HEDP-F) was synthesized and applied for the fluorescent microscope visualization of gypsum crystals formation in supersaturated aqueous solutions. The visualization of HEDP-F location at gypsum crystals, has demonstrated that the bisphosphonate molecules do not act as they are expected to do according to the current scale inhibition theory. At ambient temperature the gypsum macrocrystals are found to form, and then to grow without visible sorption of bisphosphonate on the crystal edges or any other gypsum crystal growth centers. A tentative nonconventional mechanism of scale inhibition in the bulk supersaturated aqueous solutions of gypsum is proposed.
关键词： crystal formation,scale formation,visualization,gypsum,mechanisms of scale inhibition,fluorescent-tagged bisphosphonate
更新于2025-11-19 16:46:39
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Platinum-enhanced amorphous TiO2-filled mesoporous TiO2 crystals for the photocatalytic mineralization of tetracycline hydrochloride
摘要： The adsorption ability and photoactivity of a photocatalyst largely determine the mineralization efficiency of antibiotics. Herein, aiming to enhance the adsorption and mineralization of antibiotics, we constructed a hierarchical porous core-shell structure by filling amorphous TiO2 in the pores of Pt-doped mesoporous TiO2 crystals (MCs). The physical–chemical properties of the prepared samples were investigated by surface photovoltage spectroscopy, X-ray photoelectron spectroscope, etc. Adsorption and photocatalysis experiments were conducted with tetracycline hydrochloride as the model antibiotic. Pt nanoparticles doped at the interface of the rutile-amorphous homojunction remarkably enhanced the built-in electric field. The enhanced electric field increased the hole transfer to the catalyst surface, and the Pt doping treatment promoted the growth of amorphous TiO2 into the mesopores of the MCs. The optimization increased the surface area of the catalyst without increasing the thickness of the amorphous TiO2 shell, thereby reducing the charge migration distance from the core–shell interface to the catalyst surface. The adsorption amount and mineralization efficiency of tetracycline hydrochloride for the porous core-shell composite were 6.7 and 3.8 times of those for MCs, respectively.
关键词： Crystal,Amorphous TiO2,TCH,Mesoporous TiO2,SPV,Charge carriers
更新于2025-11-14 17:04:02
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Effective synthesis of nanoscale anatase TiO <sub/>2</sub> single crystals using activated carbon template to enhance the photodegradation of crystal violet
摘要： Nanoscale anatase TiO2 single crystals were successfully synthesized using three kinds of activated carbon (AC) templates through a simple sol–gel method. The optimal photocatalyst (T‐WOAC) was obtained using wood‐based AC template. X‐ray diffraction, transmission electron microscopy and Brunauer–Emmett–Teller analyses revealed that T‐WOAC possessed a small crystallite size of 8.7 nm and a clear mesoporous structure. The photocatalytic properties of samples were then evaluated through photodegradation of crystal violet (CV). Results implied that the photocatalysts prepared using the AC templates exhibited superior photocatalytic activity to that of the original TiO2. This enhancement may be due to the small crystallite size, large specific surface area and pore volume of the catalysts prepared with ACs. T‐WOAC showed high photocatalytic activity, CV degradation of 99.01% after 120 min of irradiation and k = 0.03914 min?1, which is 3.9 times higher than that of the original TiO2 (k = 0.00994 min?1). This result can be mainly attributed to the application of WOAC with moderate specific surface area and pore volume to produce T‐WOAC. Alkaline conditions benefitted the photodegradation of CV over photocatalysts. This work proposes a possible degradation mechanism of CV and indicates that the fabricated photocatalysts can be used to effectively remove CV from aqueous solutions.
关键词： photocatalyst,anatase TiO2 single crystals,sol–gel,crystal violet,activated carbon
更新于2025-11-14 17:04:02
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Excellent catalysis of TiO2 nanosheets with high-surface-energy {001} facets on hydrogen storage properties of MgH2
摘要： Transition metal compound is one of the highly efficient catalysts in improving the reaction kinetics of hydrogen storage materials. Among all the transition metal, titanium and its compounds show great catalytic effect on magnesium hydride. In this paper, TiO2 nanosheets with exposed {001} facets were synthesized and doped into MgH2 for the first time. The TiO2 nanosheets (NS) doped MgH2 shows superior kinetic performance and lowest desorption temperature. The onset temperature of MgH2 + 5 wt% TiO2 NS to release hydrogen is 180.5 °C and the corresponding peak temperature is 220.4 °C, which are greatly lower than those of pure MgH2 and also distinctly lower than those of MgH2 + 5 wt% TiO2 nanoparticles (NP). For isothermal dehydrogenation analysis, the MgH2 + 5 wt% TiO2 NS can release 6.0 wt% hydrogen within 3.2 min at 260 °C and desorb 5.8 wt % hydrogen within 6 min at 240 °C. It is worth noting that the MgH2 + 5 wt% TiO2 NS can even release 1.2 wt% hydrogen at a temperature as low as 180 °C within 300 min. The hydrogenation kinetics of MgH2 + 5 wt% TiO2 NS is also greatly improved, which could absorb hydrogen within only a few seconds at the mild temperature. It can uptake 3.3 wt% hydrogen at 50 °C and 5.4 wt% at 100 °C within 10 s. It is demonstrated that the tremendous enhancement in reaction kinetics of MgH2 can be ascribed to the nanometer size and highly active {001} facets of anatase TiO2. The higher average surface energy can significantly reduce the hydrogen desorption activation energy of MgH2 to 67.6 kJ/mol, thus easily improves the hydrogen desorption properties.
关键词： Magnesium hydride,Hydrogen storage,Catalytic effects,crystal facets,TiO2
更新于2025-11-14 17:03:37
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Syntheses, crystal structures, and photocatalytic properties of two zinc(II) coordination polymers based on dicarboxylates and flexible bis(benzimidazole) ligands
摘要： Two new ternary zinc(II) coordination polymers (CPs), catena-(μ2-phthalato)-(μ2-1,1'-hexane-1,6-diylbis(2-methyl-1H-benzimidazole))-zinc (CP 1) and catena-(μ2-phenylene-1,4-diacetato)-(μ2-1,1'-hexane-1,6-diylbis(1H-benzimidazole))-zinc (CP 2) were synthesized via hydrothermal process. CP 1 and CP 2 are named as [Zn(L1)(PA)]n and [Zn(L2)(PDA)]n (L1 = 1,1'-hexane-1,6-diylbis(2-methyl-1H-benzimidazole), L2 = 1,1'-hexane-1,6-diylbis(1H-benzimidazole), H2PA = phthalic acid, H2PDA = 1,4-phenylenediacetic acid)), respectively. Both CPs were characterized by elemental analysis, infrared spectroscopy, single crystal X-ray diffraction analysis. CP 1 possesses a 4-connected 66-dia network, CP 2 displays a 2D hcb layer with point symbol {63}. Luminescence, UV-vis diffuse reflection spectra, and photocatalytic properties of two CPs for the degradation of the methylene blue (MB) dye were investigated. The mechanism of photocatalytic degradation of MB was also suggested.
关键词： Zinc(II),Crystal structure,Bis(benzimidazole),Photocatalytic property,Coordination polymer
更新于2025-11-14 15:28:36
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A flexible surface-enhanced Raman substrates based on cellulose photonic crystal/Ag-nanoparticles composite
摘要： Surface-enhanced Raman scattering (SERS) significantly increases Raman scattering intensity. SERS usually uses rough-surface nano-metal materials such as gold, silver and copper as a substrate [1]. It has been widely used in surface science, analytical science and other fields [2-4]. According to the preparation method, SERS substrates can be divided into three categories: (1) solid phase substrates with fixed metal nanoparticles [5, 6]; (2) metal nanostructures prepared by nanoimprinting [7, 8]; (3) metal nanostructures prepared by template method [9-11]. Conventional SERS substrates, such as roughened surfaces of noble metals, are difficult to control and the SERS effect is unstable due to the random distribution of nanostructures. The microstructure of the nanometer regular pattern, which is processed by etching and electron beam deposition, is limited by the high cost of the instrument, the complicated production process, the difficulty to make large area and the subsequent modification of the surface. The SERS substrate prepared by a template of nanospheres array has a good controllability and reproducibility. By assembling nanospheres with different sizes to prepare the templates of different thicknesses, 2D metal films with different spacing can be obtained. The preparation of SERS substrate based on nanospheres array is simple and has low cost, easy regulation and high reproducibility. Protective agent and surfactant are not required in the preparation, meanwhile, the obtained substrate is relatively pure. PhCs are periodic structures which can be generated by a controllable self-assembly method of the spherical colloidal particles [12-15]. Light propagated inside PhCs follows Bragg's law of diffraction [16-19]. The characteristics of PhCs strongly depend on the spatial structure. Because of its cost-efficiency and easy preparation, PhC has attracted significant attentions in the application of optical sensors, optical switches [20, 21] and display devices [22-26]. The regular periodical structures can also be used as template to prepare other structural functional materials [27]. A lot of researches on the preparation and application of PhCs have been carried out in our recent work [28, 29]. Based on the special capture effect of PhC optical bandgap, the plasma effect of silver nanoparticles and the enrichment of cellulose matrix on analytes in organic solvents, we designed a combination of three properties for enhancing Raman scattering. Design concept is as follows: a PhC array which bandgap matches the incident light is used as a template, filled with a cellulose matrix that is easily degraded, and modified with silver nanoparticles. Based on the above design, a novel surface-enhanced Raman scattering substrate made by Ag-nanoparticles modified flexible cellulose photonic crystal film was firstly prepared. We synthesized an Ag-nanoparticles modified PhCs methylcellulose film (Ag-PHC-MCF) and carboxymethyl cellulose film (Ag-PHC-CMCF) SERS flexible substrates using the PhCs as templates. The innovative combination of metal nanoparticles and the ordered PhCs cellulose film (PHCCF) effectively avoided the aggregation of metal nanoparticles, as a result, the hot spots of the metal nanoparticles were distributed around the pores to ensure the uniform adsorption of the target analytes and uniform Raman signals on a large area. Through the excellent enrichment of cellulose film with pore structures, the targets in the organic solvent were captured on the cellulose film, so the Raman detection signals of the analyte were enhanced with the contact probability between the targets and the hot spots of metal nanoparticles increasing. At the same time, the light scattered on the PHCCF was enhanced significantly because of the trapping effect of PhC. Based on the original combination of the enrichment of porous methylcellulose, the plasmon resonance of Ag and the bandgap of photonic crystal, the composite film has a significant enhancement of the Raman signals. Simultaneously, due to its good degradability, it also has outstanding advantages in environmental protection. Meanwhile, it is easy to be carried and preserved because of its flexibility and light texture, which has great superiorities in transportation and storage.Therefore, it is of great significance in industrial pollutant detection or national defense safety monitoring.
关键词： SERS,cellulose films,photonic crystal,plasmonic responses
更新于2025-11-14 15:27:09
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A new disordered langbeinite-type compound, K <sub/>2</sub> Tb <sub/>1.5</sub> Ta <sub/>0.5</sub> P <sub/>3</sub> O <sub/>12</sub> , and Eu <sup>3+</sup> -doped multicolour light-emitting properties
摘要： For the first time, a new langbeinite-type phosphate, namely potassium terbium tantalum tris(phosphate), K2Tb1.5Ta0.5(PO4)3, has been prepared successfully using a high-temperature flux method and has been structurally characterized by single-crystal X-ray diffraction. The results show that its structure can be described as a three-dimensional open framework of [Tb1.5Ta0.5(PO4)3] interconnected by K+ ions. The TbIII and TaV cations in the structure are disordered and occupy the same crystallographic sites. The IR spectrum, the UV–Vis spectrum, the morphology and the Eu3+-activated photoluminescence spectroscopic properties were studied. A series of Eu3+-doped phosphors, i.e. K2Tb1.5–xTa0.5(PO4)3:xEu3+ (x = 0.01, 0.03, 0.05, 0.07, 0.10), were prepared via a solid-state reaction and the photoluminescence properties were studied. The results show that under near-UV excitation, the luminescence colour can be tuned from green through yellow to red by simply adjusting the Eu3+ concentration from 0 to 0.1, because of the efficient Tb3+→Eu3+ energy-transfer mechanism.
关键词： photoluminescence,Langbeinite-type phosphate,crystal structure,energy-transfer mechanism,multicolour light
更新于2025-11-14 15:23:50
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First titanium square fragment {Ti4(μ4-Se)(μ2-Se2)4} in its selenoiodide: Synthesis and structure of Ti4Se9I6
摘要： The first titanium selenoiodide Ti4Se9I6 was synthesized as black crystals by heating of Ti, Se, and I2 at 250 °C in 5:9:5 M ratio. The crystal structure of the compound was solved by X-ray single-crystal diffractometry (sp. gr. P-1, a = 7.9652(10), b = 10.3390(15), c = 15.692(2) ?; α = 79.116(7)°, β = 75.861(7)°, γ = 71.437(7)°; Z = 2) with final R1 = 0.0397. The structure includes square {Ti4(μ4-Se)(μ2-Se2)4} fragment coordinated by four terminal and four bridging μ2-I atoms. Ti4+ has d0 configuration, and stability of the structure fragments is provided by metal to ligand bonding which was confirmed by DFT calculations.
关键词： Metal chalcohalides,Titanium,Square complex,Synthesis,Selenide,X-ray crystal structure,Chain structure,DFT calculations,Iodide
更新于2025-11-14 15:14:40
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Preparation of α‐Si <sub/>3</sub> N <sub/>4</sub> by direct nitridation using the polysilicon waste by diamond wire cutting
摘要： With the rapid development of the semiconductor industry and solar photovoltaic industry, a large number of polysilicon wastes from diamond wire cutting are accumulated, which not only pollute the environment, but also cause safety problems due to the ultrafine particle size and high reactivity. The diamond wire cutting polysilicon waste was used to prepare α-Si3N4 by direct nitridation method. This method could not only fully recycle the waste and reduce environmental pollution, but also reduce the production cost of α-Si3N4. Furthermore, the effects of FeCl3, NaCl and metal Cu on the nitridation of polysilicon waste are investigated in detail, respectively. It is found that FeCl3 and NaCl are not ideal additives for the preparation of α-Si3N4. However, α-Si3N4 dominated Si3N4 can be obtained via adding 5 wt. % Cu after nitridation at 1250 oC for 8 h, and the relative content of α-Si3N4 reaches 92.37 %.
关键词： silicon nitride,crystal growth,nitridation,catalysts/catalysis,powders
更新于2025-11-14 14:48:53