CHEMICAL GEOLOGY
·
2019
·
IF 3.618
Xiaolin Wang,Ye Qiu,Jianjun Lu,I-Ming Chou,Wenlan Zhang,Guanglai Li,Wenxuan Hu,Zhen Li,Richen Zhong
Knowledge on hydrothermal tungsten (W) species is vital towards a better understanding of tungsten transport and mineralization mechanisms. In this study, in situ Raman spectra of a 0.005 – 0.1 mol/kg ( m ) K 2 WO 4 solution containing CO 2 , HCl, and NaHCO 3 were collected at 50–400 °C and 20–60 MPa. The spectra for the symmetric stretching vibration mode of the W O bond, v 1 (W O), were analyzed to investigate the hydrothermal tungstate species. Results showed that carbonate/bicarbonate do not associate with tungstate to form carbonic tungstate species. Nevertheless, the presence of CO 2 can increase the fluid acidity, which favors the formation of polymeric tungstate species at <300 °C. Above about 300 °C, monomeric tungstates (e.g., WO 4 2- , HWO 4 -, H 2 WO 4 and alkali tungstate ion pairs) are responsible for the hydrothermal transport of tungsten, and the v 1 (W O) modes of these species are centered at ∼930 cm -1 and 950 cm -1 . Based on the above observations, we simulated the mineralization process in the context of fluid-rock interactions using tungstate and alkali tungstate ion pairs as the only aqueous W species. The thermodynamic simulations showed that (a) the timing of mineralization mainly depends on the W concentration in the initial mineralizing fluid and the availability of Ca 2+ , Fe 2+ and Mn 2+ , with higher W concentrations generally favoring higher temperature mineralization; (b) highly W-enriched fluid is not essential for W mineralization, while extremely low contents of Fe, Mn and Ca in the magma are useful to maintain the mobility of aqueous W until favorable host rocks are encountered; and (c) a “hydrogen reservoir” effect was identified for dissolved CO 2 . The presence of CO 2 can promote the extraction of Fe(II) from the pelitic host rocks, thereby facilitating a high-grade vein-type W mineralization. At <∼300 °C, polytungstate species, whose v 1 (W O) modes are centered at ∼965 – 995 cm -1 , are important hydrothermal W species along with monomeric tungstates. Therefore, polymeric tungstate species should be considered in future thermodynamic modeling of W transport and mineralization at <300 °C. An increase in fluid pH induced by CO 2 -escape and/or fluid-rock interactions will destabilize the polymeric tungstates to form WO 4 2- and other monomeric tungstate, which interacts with metal cations to form wolframite and/or scheelite.
研究领域:
地球化学
·
矿物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2023
·
IF 6.1
Zhiquan Chen,Yinshan Liu,Lei Ni,Juncheng Jiang,Yuan Yu,Yong Pan,Zhichao Zhu
To overcome the problems of traditional catalyst in the microreaction technology, a microreactor system with tungstate metal foam catalyst was constructed and the catalytic efficiency were investigated by dimethyl sulfoxide (DMSO) oxidation reaction as a probe reaction. Three tungstate metal (CuWO 4 , NiWO 4 , FeWO 4 ) foams were fabricated, and inherited the porous structure from the metal foam and had a high loading density of tungstate metal crystal particles. In the lab-built flat-plate microreactor, the effects of reaction temperature, residence time, molar ratio and pH on the yield of dimethyl sulfone (MSM) were investigated, and the tungstate metal foams showed prefect catalytic activity. Compared with NiWO 4 foam and FeWO 4 foam, the larger specific surface area and higher porosity endow CuWO 4 with a better catalytic performance. When the reaction temperature was 80 °C, the residence time was 40 min, the molar ratio was 1:1 and the pH value of the reaction system was 3, the yield of MSM reached 82.1%. Furthermore, the NiWO 4 foam catalyst system showed a better performance compared with other two catalyst system. This work indicates the potential opportunity of the construction of various metal foam catalysts in the versatile continuous microreaction technology.
研究领域:
化学工程
·
催化材料科学
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DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Cong Xiang,Jingyi Fang,Yanlin Huang,Zhuo Zheng,Hyo Jin Seo
Eu 3+ is not only a major red-emitting activator, but also an excellent spectral probe ion. This work reports the Eu 3+ -sites and luminescence in the cation-deficient perovskite tungstates, A-site deficient SrLa 2 (Mg 2 W 2 )O 12 [Sr 1/2 □ 1/2 La(MgW)O 6 ] and B-site deficient Sr 2 La 2 (MgW 2 )O 12 [SrLa(Mg 1/2 □ 1/2 W)O 6 ]. The 7 F 0 → 5 D 0 excitation spectra of Eu 3+ activators in two lattices were measured via pulsed dye laser. In SrLa 2 (Mg 2 W 2 )O 12 :Eu 3+ , there is only one 7 F 0 → 5 D 0 transition, which could be related to the Eu 3+ center on La 3+ sites; while, two 7 F 0 → 5 D 0 transitions in Sr 2 La 2 (MgW 2 )O 12 indicate Eu 3+ ions occupy Sr 2+ in addition to La 3+ , resulting in the luminescent centers related to heterovalent substitution defects. The different Eu 3+ sites make two phosphors exhibit different red luminescence properties. SrLa 2 (Mg 2 W 2 )O 12 :Eu 3+ shows higher luminescent efficiency and thermal quenching due to its regular distribution of the activators resulting in lower dispersion losses of the energy transfer. The experimental results show that rare earth ions occupy different crystallographic positions in A -site and B -site deficient perovskite oxides, and this microstructure can be important for the corresponding luminescent properties.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Yi Gu,Yang Jiao,Ya Ruan,Jing Yang,Yaling Yang
Herein, a nanocomposite of Cu,Ce-containing phosphotungstates (Cu,Ce-PTs) with outstanding laccase-like activity was fabricated via a one-pot microwave-assisted hydrothermal method. Notably, it was discovered that both Fe 3+ and Cr 6+ could significantly enhance the electron transfer rates of Ce 3+ and Ce 4+ , along with generous Cu 2+ with high catalytic activity, thereby promoting the laccase-like activity of Cu,Ce-PTs. The proposed system can be used for the detection of Fe 3+ and Cr 6+ in a range of 0.667–333.33 μg/mL and 0.033–33.33 μg/mL with a low detection limit of 0.135 μg/mL and 0.0288 μg/mL, respectively. The proposed assay exhibits excellent reusability and selectivity and can be used in traditional Chinese medicine samples analysis.
研究领域:
生物化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2020
·
IF 5.289
Zepeng Lv,Yijie Wu,Jie Dang,Dong Liu,Liwen Hu,Kaiping Du,Haibo Sun
The effect of yttrium on the reaction of tungsten oxide with CO was studied for the preparing various morphologies and size of tungsten carbide. The reaction rate, phase composition, particles size and morphology, surface area of samples were studied by TG (thermogravimetry), XRD (X-ray diffraction), SEM (scanning electron microscopy) and BET (Brunauer–Emmett–Teller), respectively. It was found that the reaction route was following WO 3 → W 18 O 49 → WO 2 → WC at lower temperature, while at higher temperature, an intermediate phase W was formed and then carbonized to WC. During the reaction of pure WO 3 or mixtures (1 wt.% Y(NO 3 ) 3 + WO 3 ) with CO at lower temperature, the final products almost maintained the large irregular block shape. With the increase of temperature, the large WC particles were degraded and the obtained sub-particles became much more dispersed. After the addition of yttrium nitrate, the rod-like sub-particles were transformed into more stable polyhedral-shaped sub-particles with a smaller size. Furthermore, the mechanism of effect of yttrium on prepared tungsten carbides were analyzed in detail.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SURFACE AND INTERFACE ANALYSIS
·
2022
·Vol. 55
·期 4
·288-295
·
IF 1.702
Yanan Huo,Jingxiang Zhou,Zushun Xu,Tianyou Chen,Haonan Ji,Fanbao Zeng,Yun Wang,Xiaoxi Hu
Photochromic coatings have been widely used in many fields such as architecture, transportation, and military because of the combination of reversible color-changing properties with the insulation and protection of substrates. Conventionally, organic photochromic components are used for the preparation of photochromic coatings with fast photo-response and excellent fatigue resistance, but the preparation of these coatings is costly and time-consuming. Here, we have developed a relatively simple and cost-effective strategy for the preparation of water-based photochromic polyurethane coatings. Er(III)-doped WO 3 was synthesized and used as the photochromic component for the preparation of polyurethane/Er(III)-doped WO 3 composites, which were further used for the preparation of photochromic coatings. The properties of the coatings were tested and characterized. Due to their excellent thermal stability, water resistance, fatigue resistance, and photochromism, these coatings might have practical applications in various areas.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Jingwen Guan,Xiaomei Wang,Yemeng Chen,Hailong Zhang,Zongyi Li,Ao Li,Fuwan Zhai,Lanhua Chen,Lei Chen,Ximeng Li,Bin Chen,Yigong Xu,Xiao Dong,Wei Liu,Xing Dai,Shuao Wang,Juan Diwu
The internal contamination of uranium poses severe health risks to both professionals and the public in case of nuclear accidents due to its chemo- and radiotoxicity. Although chelation therapy has been considered the only practical treatment in emergencies, current clinical chelators show only limited efficacy for uranium. Herein, a recently designed lacunary selenotungstate polyoxometalate (Se6W45) was demonstrated as an effective therapeutic agent. In this construct, the open site in Se6W45 provides a suitable uranium binding environment, resulting in the selective removal of uranium from kidneys (85.87%) and femurs (39.81%) with an extremely low ligand/metal ratio of only 4:1. The redox active sites in Se6W45, primarily the incorporated selenium, were able to reduce the intracellular reactive oxygen species (ROS) to normal levels in NRK-52E cells exposed to uranium. This approach overcomes the disadvantages of the excessive use of current chelating ligands in the range from 100- to 1000-folds, avoiding the consequential depletion of heterogeneous cations, dysfunction of proteins, and/or acid–base imbalance. More importantly, it provides a synergistic antidotal therapy for uranium in reducing radiation damage and chemical toxicity.
研究领域:
放射生物学
·
毒理学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Biobased Materials and Bioenergy
·
2019
·Vol. 13
·期 5
·677-682
·
IF 0
Zhu Qiao-Qiao,Zhuang Jun-Ping,Wang Lan-Ying,Liu Ying,Wu Shu-Bin
Three kinds of silicotungstate, Zn2SiW12O40, Ag4SiW12O40 and Al4/3SiW12O40 were performed for the dehydration reaction to produce valuable platform chemicals levulinic acid
(LA) and 5-hydroxymethylfurfural (HMF) from glucose. The results showed that Al4/3SiW12O40 seemed beneficial for LA and HMF production from glucose. The highest LA yield of 50.4% was obtained when the glucose conversion was almost 100% at 180 °C
for 120 min with glucose was 0.5 g and the catalyst dosage was 0.45 g. The recycling of Al4/3SiW12O40 catalyst can be reused at least for four times with the activity loss less than 18.4% and the SEM images showed that the activity loss less may
due to the formation of the clustered fine particles on catalyst surface. This work provided a promising strategy for the production of LA from carbohydrates using inexpensive silicotungstate catalysts in aqueous medium.
研究领域:
化学工程
·
可再生化学
✓ 已验证
DOI
Advanced Materials Technologies
·
2025
·
IF 6.2
Haoming Xu,Wenli Li,Imtiaz Haider,Yuhua Zheng,Mianqi Xue,Jiechao Ge,Bao Wang,Serge Zhuiykov,Yanbin Cui
Structural design and interlayer architecture of electrochromic (EC) materials play significant role in their performance. Herein, tungsten trioxide (WO 3 ) nanoflowers have been synthesized through in situ intercalation with polyaniline (PANI), developing a 3D hierarchical structure with optimized interlayered spacing. The PANI-WO 3 composite showed superior EC stability due to improved ion storage capacity by 3D hierarchical structure with extended surface area for ion interaction. The enlarged layer spacing of PANI-WO 3 composites allows for accommodating more exchangeable Li + . The PANI-WO 3 film maintains remarkable cycling stability, retaining 80% of its initial capacity after 30000 cycles. The EC device based on PANI-WO 3 demonstrates high optical modulation (57% at 633 nm), rapid switching speeds (coloration to 23% in 15 s and bleaching to 80% in 10 s) and high coloration efficiency (168 cm 2 C −1 ). Meanwhile, the PANI-WO 3 EC supercapacitor achieves a high specific capacitance (121 mF cm −2 at 0.2 mA cm −2 ) and prolonged cyclic life (specific capacity remains at 58% and coulombic efficiency at 65% after 1500 cycles). The PANI-WO 3 serves as an effective candidate for the fabrication of high-performance EC devices (ECDs) with potential applications in energy-saving smart windows, outdoor static displays, and other energy-efficient technologies.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Juan Qiu,Xiang Gao,Guiqiu Li,Kanglu Feng,Kangwei Gongsun,Chunchao Chen,Changming Bu,Houyi Ma
An approach to fabricate protective film on copper substrate utilizing molybdate or tungstate assisted by dithiol was proposed. The fabricated films exhibited double-layer structure. The top layer was an organic layer primarily composed of interconnected dithiol molecules through disulfide bonds originating from the oxidation of molybdate or tungstate. The Cu 2 S bottom-layer formed as a result of the cleavage of C-S bonds subsequent to the adsorption of dithiol molecules onto the copper matrix. The molybdate participated the film via MoO x and MoS x . Although no tungstate species were detected in the film, the oxidizing effect of tungstate facilitated a conversion of dithiol molecules into polymers, resulting in a significantly thicker surface layer. The corrosion protection efficiencies of the films reached 99.7 % and 99.8 %, respectively, attributed to the incorporation of molybdate or tungstate additives. Theoretical calculations provided valuable insights into the process of film formation and elucidated the relationship between film structure and anti-corrosion performance.
研究领域:
材料科学
·
电化学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Yunan Wang,Yingying Sun,Qian Long,Jie Liu,Di Guo,Zhengwang Zhu,Haifeng Zhang
Orthorhombic tungsten oxide (WO 3 ·H 2 O) has been considered as a promising anode material due to its layered crystal structure and high capacity. However, the instability of its crystal structure usually results in poor cyclic stability of the battery/capacitor. Herein, a novel strategy of introducing aluminum ion (Al 3+ ) additives for designing hybrid electrolyte is demonstrated to enhance the cycling stability of WO 3 ·H 2 O. Aluminum ions may participate in the redox reaction and contribute extra capacitance. More importantly, the Al 3+ ions can facilitate fast phase transformation of metastable orthorhombic tungsten oxides to stable monoclinic phase, but also participate in the construction of stable protective layer during the long-term cycling, forming a protective layer at the surface of tungsten oxide for alleviating the dissolution and structural damage. The WO 3 ·H 2 O is electrodeposited on the exfoliated graphite foil (Ex-GF) and shows a specific capacitance of 395 mF cm −2 at 2 mA cm −2 in the LiCl + AlCl 3 hybrid electrolyte (pH = 2.93), and the capacitance remains 91.8 % after 10,000 charge/discharge cycles, indicating that the WO 3 ·H 2 O/Ex-GF electrode material exhibits excellent stability in supercapacitors. The density functional theory (DFT) calculations further demonstrate whether the adsorption energy or intercalation energy of Li + at the monoclinic WO 3 is lower than the orthorhombic WO 3 ·H 2 O. This result suggests that the electrochemical performance of WO 3 ·H 2 O, which operates on a pseudocapacitive reaction mechanism, can be enhanced through the phase transformation from the orthorhombic phase to the monoclinic phase during the cycling. Hence, this ion additive approach can adjust the interface composition and protect internal active material, and can be extended to the stability improvement of other metal oxide electrodes.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemCatChem
·
2018
·Vol. 10
·期 14
·3040-3048
·
IF 4.674
Tingxia Hu,Haiping Li,Na Du,Wanguo Hou
Graphical Iron rules : Fe-doped Bi 2 WO 6 exhibits a much higher photoactivity than Bi 2 WO 6 because of the introduction of the dopant and defect energy levels. The metal-doping of Bi-based oxide photocatalysts to enhance the photocatalytic performance has been a research hotspot in recent years, but the research on the mechanism of doping-induced photoactivity improvement is still incomplete. To illustrate the mechanism completely and clearly, Fe-doped Bi 2 WO 6 , as an example, was synthesized by a facile hydrothermal route. Fe-doped Bi 2 WO 6 exhibits a much higher photoactivity than pure Bi 2 WO 6 in the degradation of Rhodamine B (RhB) and salicylic acid (SA). By replacing W 6+ , the Fe 3+ doping narrows the energy band gap and generates many oxygen vacancies, which can increase the adsorption of both RhB and SA, and the introduced defect and Fe-doping energy levels in the band gap of Bi 2 WO 6 increase the separation efficiency of photoinduced charge carriers significantly. These lead to the considerable photoactivity enhancement of Fe-doped Bi 2 WO 6 . The photoactivity of Fe-doped Bi 2 WO 6 is stable and superior to that of most reported modified Bi 2 WO 6 photocatalysts. This work illustrates in detail the mechanism for the photoactivity improvement of Fe-doped Bi 2 WO 6 , which benefits the research of other metal-doped photocatalysts.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）