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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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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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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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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
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Two new olefin-Cu(I) coordination polymers based on 2,5-dimethyl piperazine: Synthesis, crystal structure and fluorescent property
摘要： Two new olefin-Cu(I) coordination polymers, i.e. [Cu6(DMBVBP)Cl8]n (1) and [Cu6(DMBVBP)Br8]n (2) (DMBVBP ? 2,5-dimethyl-1,4-bis(4-vinylbenzyl) piperazine), were synthesized through the solvothermal reactions of CuCl, CuBr and 2,5-dimethyl piperazine and further characterized by elemental analysis, infrared spectroscopy, as well as powder and single crystal X-ray diffraction analyses. The title complexes crystallized in the monoclinic P-1 space group, both featuring a one-dimensional chain. Their fluorescent properties were also investigated.
关键词： fluorescence,Olefin-Cu(I) coordination polymer,hydrothermal synthesis
更新于2025-09-19 17:15:36
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The role of GQDs additive in TiO2 nanorods as an electron transfer layer on performance improvement of the perovskite solar cells
摘要： The electron transport layer (ETL) plays an important role in improving the performance of the perovskite solar cells (PSCs). The main focus is on different types of TiO2 structures as an efficient ETL. In the present work, TiO2 nanorods (NRs) are prepared by a simple one-step hydrothermal method and employ as an ETL in PSCs. The power conversion efficiency (PCE) of the TiO2 NRs based PSCs is improved about 217% compared with the mesoporous (mp) TiO2 based cells. In order to further enhance PCE of the PSCs, a new approach is adopted to synthesize the graphene quantum dots- TiO2 NRs (GQDs- TiO2 NRs) by hydrothermal method. The PCE of PSCs based on GQDs- TiO2 NRs show improvement of 1.34 times compared to the TiO2 NRs. The GQDs- TiO2 NRs is capable of being a promising alternative to be employed as an efficient electron transport materials for photovoltaic devices.
关键词： TiO2 nanorods,Perovskite solar cells,Hydrothermal synthesis,Graphene quantum dots
更新于2025-09-19 17:13:59
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Controlled growth of SrxBa1a??xNb2O6??hoppera?? and cubea??shaped nanostructures by hydrothermal synthesis
摘要： Controlling the shape and size of nanostructured materials has been a topic of interest in the field of material science for decades. In this work, the ferroelectric material SrxBa1-xNb2O6 (x = 0.32–0.82, SBN) was prepared by hydrothermal synthesis, and the morphology is controllably changed from cube-shaped to hollow-ended structures based on a fundamental understanding of the precursor chemistry. Synchrotron X-ray total scattering and PDF analysis was used to reveal the structure of the Nb-acid precursor, showing Lindqvist-like motifs. The changing growth mechanism, from layer-by-layer growth forming cubes to hopper-growth giving hollow-ended structures, is attributed to differences in supersaturation. Transmission electron microscopy revealed an inhomogeneous composition along the length of the hollow-ended particles, which is explained by preferential formation of the high entropy composition, SBN33, at the initial stages of particle nucleation and growth.
关键词： SrxBa1-xNb2O6,hydrothermal synthesis,SBN,hopper crystal,niobic acid
更新于2025-09-19 17:13:59
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Optical properties of hydrothermally synthesised and thermally annealed ZnO/ZnO <sub/>2</sub> composites
摘要： ZnO/ZnO2 composites grown by hydrothermal synthesis at low temperature (180 °C) and thermally annealed at 300 °C were fully analysed by morphological, structural and optical techniques. X-ray diffraction patterns (XRD) and Raman spectroscopy clearly evidences the presence of both crystalline phases in the ZnO/ZnO2 sample. The differential scanning calorimetry analysis and thermogravimetric profiles indicate an exothermic event with a peak temperature ca. 225 °C, which is accompanied by a 8.5 % weight loss, being attributed to the crystallization of ZnO from ZnO2. Upon a thermal annealing treatment at 300 °C in the ZnO2 phase was completely converted into ZnO as measured by XRD and Raman spectroscopy. Photoluminescence investigations reveal that the emission is dominated by a broad band recombination in both samples, which are due to the overlapping of different emitting centres, and that the peak position of the PL emission is dependent on the excitation density. The ZnO/ZnO2 sample exhibits a widening of the bandgap when compared to the one only containing ZnO, likely related with the presence of the additional ZnO2 phase and suggesting a bandgap energy of 3.42 eV for this compound. Surface analysis revealed that sample exhibits a surface area of 90 m2/g, which decreases to 30 m2/g after the thermal annealing and the full conversion into ZnO. This difference in the surface area showed a particular relevance in the stability of the measured optical properties. Particularly, the intensity of the photoluminescence signal was seen to be higher in the ZnO/ZnO2 sample and strongly dependent on the measurement atmosphere, highlighting their potential to be employed in the fabrication of optical-based sensing systems for environmental applications, namely in gas sensors.
关键词： photoluminescence,gas sensors,ZnO/ZnO2 composites,hydrothermal synthesis,optical properties
更新于2025-09-19 17:13:59
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Low-temperature Synthesized Nba??doped TiO <sub/>2</sub> Electron Transport Layer enabling High-efficiency Perovskite Solar Cells by Band Alignment Tuning
摘要： An Nb-doped TiO2 (Nb-TiO2) film comprising a double structure stacked with a bottom compact layer and top mesoporous layers was synthesized by treating a Ti precursor-coated substrate using a one-step low-temperature steam-annealing (SA) method. SA-based Nb-TiO2 films possess high crystallinity and conductivity, and that allows better control over the conduction band (CB) of the TiO2 for electron transport layer (ETL) of the perovskite solar cells (PSCs) by the Nb doping level. Optimization of power conversion efficiency (PCE) for the Nb-TiO2 based ETL was combined with CB level tuning of the mixed-halide perovskite by changing the Br/I ratio. This band offset management enabled to establish the most suitable energy levels between ETL and perovskites. This method was applied to reduce the bandgap of perovskite to enhance photocurrent density while maintaining a high open-circuit voltage. As a result, the optimal combination of 5 mol% Nb-TiO2 ETL and 10 mol%-Br in the mixed-halide perovskite exhibited high photovoltaic performance for low-temperature device fabrication, achieving a high yield PCE of 21.3%.
关键词： low-temperature process,solvent-free hydrothermal synthesis,electron transport layer,steam-annealing method,Perovskite solar cell,niobium-doped TiO2
更新于2025-09-19 17:13:59