JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2023
·
IF 3.5
Yichen Ye,Yongbao Xiao,Yao Ji,Weichao Wang
Singly Ho 3+ -doped TeO 2 –Ta 2 O 5 –ZnO (TTZ) glass and optical fiber for 2 μm fiber lasers have been investigated. The glass-forming region of the ternary TTZ glass system is determined to study its glass-forming ability and to select an appropriate glass matrix for doping Ho 3+ ions. Upon the excitation of a 1940 nm laser diode (LD), an intense emission at 2.06 μm with a full width at half maximum (FWHM) of 61 nm is observed from the Ho 3+ -doped TTZ glass. The measured lifetime of the Ho 3+ : 5 I 7 level in TTZ glass shows a gradual decrease from 3.5 to 0.98 ms as the dopant concentrations increase from 0.2 to 2 mol%. A large emission cross-section (σ e MC ∼ 4.56 × 10 −21 cm 2 ) and figure of merit (FOM, ∼ 6.83 × 10 −24 cm 2 ·s) are obtained. The Ho 3+ -doped TTZ glass is further fabricated into an optical fiber with an average transmission loss of 0.12 dB/cm at 1310 nm. The results show that singly Ho 3+ -doped TTZ glass and optical fiber are promising candidates for efficient 2 μm fiber lasers.
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高影响因子
Journal of the American Chemical Society
·
2019
·
IF 14.695
Zhong-Xia Wang,Yi Zhang,Yuan-Yuan Tang,Peng-Fei Li,Ren-Gen Xiong
Antiperovskites have developed to be one kind of important functional material over the past few decades, showing abundant physical properties such as negative thermal expansion and superconductivity, etc. However, antiperovskite ferroelectrics have scarcely been discovered in inorganic ceramics. In this article, we report a new organic–inorganic hybrid antiperovskite ferroelectric [(CH3)2(F-CH2CH2)NH]3(CdCl3)(CdCl4) based on the strategy of molecular design. The replacement of one methyl in [(CH3)3NH]CdCl3 with ethyl produces the lower symmetric [(CH3)2(CH2CH3)NH]CdCl3 with nonpolar perovskite structure, while the polar hexagonal antiperovskite structure with the formula of X3BA (where X = [(CH3)2(F-CH2CH2)NH]+, B = [CdCl3]−, and A = [CdCl4]2–) was received after further fluoridation of the ethyl group. Therefore, fluoridation successfully achieves the structural transformation from perovskite to antiperovskite, as well as the significant changes in physical properties from nonferroelectric to ferroelectric. The antiperovskite [(CH3)2(F-CH2CH2)NH]3(CdCl3)(CdCl4) exhibits typical ferroelectric phase transition above room temperature (Tc = 333 K) including thermal anomalies, dielectric transitions, and second harmonic generation (SHG) responses. Moreover, lower coercive fields and easy polarization switching are observed by the measurements of hysteresis loops and ferroelectric domains. The saturated polarization (Ps) of 4.0 μC/cm2 is almost 10 times as large as those recently discovered antiperovskite molecular ferroelectrics. This finding provides a novel strategy to design and explore more antiperovskite organic–inorganic hybrid ferroelectric materials.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Jinwen Hu,Xiangbin Cai,Jiao Wu,Cuncun Xin,Jingya Guo,Ziruo Liu,Jiazhen Wei,Xusheng Cheng,Ce Hao,Haopeng Dong,Guifeng Zhang,Ning Wang,Yongpeng Lei,Wei Liu,Yantao Shi
Endowing the transition-metal-nitrogen-carbon (M-N-Cs) electrocatalysts with high oxygen reduction activity for sustainable energy conversion, is a field of intense research while remains elusive. Here we exploit the variable configuration of atomically dispersed Cu 1 centers on carbon support via rationally constructing prototypical CuN 2+2 active sites to boost the kinetically sluggish electrochemical oxygen reduction. Density functional theory reveals the modified electronic structure of active Cu site and its derived orbital overlap through right symmetry with the degenerate π* orbital of O 2 molecule, which more effectively facilitates O 2 activation compared with CuN 4 counterpart. The targeted electrocatalyst delivers superior alkaline ORR activity with a half-wave potential of 0.88 V and superior kinetics with Tafel slope of 48 mV dec −1 , outperforming those of benchmark Pt/C. Remarkably, further demonstrated excellent peak power density and long-term durability in both primary liquid and flexible solid-state Zn-air battery assemblies signify the potential for practical applications.
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 6
·062504
·
IF 4.386
Fangzhao Pang,Peng Li,Zhuqing Zhao,Lei Guo,Kaifa Du,Bowen Deng,Dihua Wang,Huayi Yin
Electrolysis of solid oxides in molten CaCl2 has been proven a straightforward process to extract various metals thanks to the wide electrochemical window of CaCl2 and CaO which is soluble in molten CaCl2. However, the CaO produced during the cathodic reduction of oxides not only shuttles O2−, but also captures CO2 to generate CO32− that can be reduced to carbon at the cathode, resulting in decreasing current efficiency and contaminating the cathodic products by carbon. To solve this problem, we employed CaSiO3 to replace CaO to suppress/avoid the formation of CO32− and thereafter prevent the carbon deposition. The suppression of CO32− formation is because SiO32− is thermodynamically more stable than CO32−, i.e., the CO2 generated on the graphite anode can not be captured by SiO32−. In molten CaCl2−8.0 wt% CaSiO3, Cr2O3 and SiO2 are reduced to Cr and Si with much less carbon deposition than in molten CaCl2. As a result, the current efficiency increases from 21.4% to 51.9% for the reduction of Cr2O3 and 37.1% to 72.2% for the reduction of SiO2. Although introducing SiO32− will slightly decrease the electrochemical window of CaCl2, it will be a promising method to avoid carbon contamination and increase current efficiency especially for Si production.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Xuelei Feng,Jianguang Yuan,Yujie Lv,Bogu Liu,Haixiang Huang,Bao Zhang,Youhua Yan,Shumin Han,Ying Wu
Magnesium borohydride (Mg(BH 4 ) 2 ) is an attractive materials for solid-state hydrogen storage due to its high hydrogen content (14.9 wt%). In the present work, the dehydrogenation performance of Mg(BH 4 ) 2 by adding different amounts (10, 20, 40, 60 wt%) of two-dimensional layered Ti 3 C 2 MXene is studied. The Mg(BH 4 ) 2 -40 wt% Ti 3 C 2 composite releases 7.5 wt% hydrogen at 260 °C, whereas the pristine Mg(BH 4 ) 2 only releases 2.9 wt% hydrogen under identical conditions, and the onset desorption temperature decreases from 210 °C to a relative lower temperature of 82 °C. The special layered structure of Ti 3 C 2 MXene and fluorine plays an important role in dehydrogenation process especially at temperatures below 200 °C. The main dehydrogenation reaction is divided into two steps, and activation energy of the Mg(BH 4 ) 2 -40 wt% Ti 3 C 2 composite is 151.3 kJ mol −1 and 178.0 kJ mol −1 , respectively, which is much lower than that of pure Mg(BH 4 ) 2 .
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高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Bao Guo,Xiaohui Lin,Ian J. Burgess,Chun Yu
In this paper, shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS) has been applied to investigate the adsorption of typical collectors, butyl xanthate and 2-mercaptobenzothiazole (MBT), on pyrite surface. With the help of inert shell isolated gold nanoparticles as electric field enhancers, high quality electrochemical spectra were obtained in relation to real-world flotation conditions, enabling the quantitative identification of the chemical reactions occurring only on the mineral surface. It has been found that polysulphide anions are predominant oxidation product of pyrite after abrading and above 0 mV vs Ag/AgCl. Both the adsorption of xanthate and MBT are suppressed on pre-oxidized pyrite surface. The pre-formed polysulphide is diminished at negative potentials, which are favourable for collector’s adsorption. Compared to xanthate, MBT shows greater resistance to pyrite oxidation and a broader potential window for adsorption due to the presence of two “minerophilic” groups (endocyclic nitrogen atom bonding in addition to the interaction through the exocyclic S atom). Single exocyclic S atom bonding is predominant in more favarouble adsorption environments. Dithiolate, the oxidation products of xanthate and MBT, has been precluded due to the high stability of adsorbed collector. This is inconsistent with the ex-situ XPS measurement where air exposure may induce oxidation.
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高影响因子
RSC Advances
·
2021
·Vol. 11
·期 52
·32654-32670
·
IF 3.361
Chang Yu,Min Liang,Su-Yi Dai,Hai-Jun Cheng,Li Ma,Fang Lai,Xiong-Min Liu,Wei-Guang Li
Cinnamaldehyde, cinnamyl alcohol, β-methylstyrene and cinnamic acid are four important biomass 3-phenyl-2-propene compounds. In the field of perfume and organic synthesis, their thermal stability and oxidation pathways deserve attention. This paper reports a new attempt to investigate the thermal stability and reactivity by a custom-designed mini closed pressure vessel test (MCPVT). The pressure and temperature behaviors were measured by MCPVT under nitrogen and oxygen atmosphere. The temperature of initial oxygen absorption (Ta) and rapid oxidation (TR) were calculated. The results showed that four 3-phenyl-2-propene compounds were stable under nitrogen atmosphere. The Ta of cinnamaldehyde, cinnamyl alcohol, β-methylstyrene, and cinnamic acid was 271.25 K, 292.375 K, 323.125 K, and 363.875 K, and their TR was 301.125 K, 332.75 K, 357.91 K, and 385.375 K, respectively. The oxidation reactivity order was derived to be cinnamaldehyde > cinnamyl alcohol > β-methylstyrene > cinnamic acid. The oxidation kinetics were determined using n versus time (n–t) plots, which showed a second-order reaction. Peroxide was determined by iodimetry, and the oxidation products were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the peroxide value of cinnamaldehyde, cinnamyl alcohol, β-methylstyrene, and cinnamic acid reached 18.88, 15.07, 9.62, and 4.24 mmol kg−1 at 373 K for 6 h, respectively. The common oxidation products of four 3-phenyl-2-propene compounds were benzaldehyde, benzoic acid, and epoxide, which resulted from the carbon–carbon double bond oxidation. The substituents' oxidation products were obtained from the oxidation of cinnamaldehyde, cinnamyl alcohol, and β-methylstyrene. In particular, the difference is that no oxidation products of the carboxyl group of cinnamic acid were detected. The common oxidation products of the four 3-phenyl-2-propene compounds were benzaldehyde, benzoic acid, and epoxide, which resulted from the carbon–carbon double bond oxidation. The substituents' oxidation products were caught in the oxidation of cinnamaldehyde, cinnamyl alcohol, and β-methylstyrene. In particular, the difference is that no oxidation products of the carboxyl group of cinnamic acid were detected. According to the complex oxidation products, important insights into the oxidation pathways were provided.
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高影响因子
MATERIALS SCIENCE-POLAND
·
2024
·Vol. 42
·期 2
·70-80
·
IF 1.3
Yanling Yu,Biwu Huang,Yafen Qu,Junshan Qiu,Yong Lai
[2-(3,4-epoxycyclohexyl) ethyl] triphenylsilane was synthesized, using triphenylsilane and 1,2-epoxy-4-vinylcyclohexane as the main raw materials. When the molar ratio of triphenylsilane to 1,2-epoxy-4-vinylcyclohexane was 1.0:1.2, the content of Wilkinson catalyst was 0.4%, the reaction temperature was 90°C, and the reaction time was 6 hours, the yield of [2-(3,4-epoxycyclohexyl) ethyl] triphenylsilane could reach 95.21%. The structure of the synthesized product was analyzed and characterized using FT-IR and 1H-NMR. The synthesized product was added to a bisphenol A-type epoxy resin (E-51) and a modified amine (593 amine) to prepare an adhesive. Then, the adhesive was poured into the mold and cured at 35°C for 8 hours. The cured sample exhibited the best performance when the ECETPS: E-51:593 amine molar ratio was 0.8:7.2:2. Thermal gravimetric analysis (TG) showed that the thermal stability of the cured samples increased relative to pure E-51 amine-cured samples with the synthesized product added. The mechanical properties of the samples were tested using a universal material testing machine, and the results showed a tensile strength of 37.95 MPa and a bending strength of 39.10 MPa.
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高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2015
·
IF 2.979
Yi Min,Zhigang Sui,Zhen Liang,Lihua Zhang,Yukui Zhang
Superficially porous particles (SPPs) demonstrate superior efficiency than totally porous particles in chiral separations. In order to obtain high efficiency and fast separation, sub-2 μm SPPs with high surface area are synthesized, and with teicoplanin bonded, such materials are successfully applied into the rapid enantioseparation of native amino acids. In brief, 1.27 ± 0.06 μm nonporous silica particles are prepared by a modified seeded growth method, followed by mesoporous shell fabrication via one-pot templated dissolution and redeposition strategy, and pore size expansion via acid-refluxing. The diameter of the formed SPPs is 1.49 ± 0.04 μm, with the shell thickness as 206 nm. Nitrogen physisorption experiments show that the Brunauer–Emmett–Teller (BET) specific surface area is 213.6 m 2 /g and pore size is 9 nm. After teicoplanin derivatization with bonding capacity as 83.3 μmol/g, the prepared chiral stationary phase is packed into a stainless steel tube with the geometry of 50 mm × 2.1 mm i.d.. In less than 6.4 min, six native amino acids (norleucine, alanine, valine, methionine, leucine, norvaline) are enantioseparated with resolution factors ranging from 1.9 to 5.0. Besides, the resolution for chiral separation is improved with ethanol-water instead of methanol-water as the mobile phase. Moreover, the low temperature gives higher resolution, but longer retention time and higher backpressure. Finally, the effect of flow rate on enantiomeric separation is studied and fast chiral separation within 1 min is obtained with flow rate of 0.4 mL/min. All these results show that the synthesized teicoplanin bonded sub-2 μm SPPs have great potential to achieve the enantioseparation of native amino acids with high resolution and rapid speed.
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高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Xiaodong Zhang,Bohui Xu,Deshuai Xiao,Linfeng Dong,Xinyuan Zhang,Pifu Gong,Zheshuai Lin
In modern optics, birefringent materials that can manipulate light polarization play important roles in lasers and information fields. The search for ultraviolet (UV) crystals with large birefringence is the focus of attention in the field of optical materials. In this work, we synthesized two birefringent crystals, C2H12N6C4O4·2H2O and Na2C4O4·3H2O, containing planar π-conjugated [C4O4]2– groups. Attributed to the large structural anisotropy and relatively ordered arrangement of the [C4O4]2– groups, C2H12N6C4O4·2H2O and Na2C4O4·3H2O possess large birefringence of 0.20–0.21 at 1064 nm. Meanwhile, they exhibit short ultraviolet cutoff edges at about 280–300 nm, corresponding to the large band gaps of 4.35 and 4.24 eV, respectively. Using structural analysis and first-principles calculations, the origins of such large birefringence are investigated and discussed. This work provides two potential UV birefringent crystals and prompts the search for novel birefringent materials.
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高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2022
·
IF 7.305
Jinpeng Lv,Xiangyu Wen
Passive thermal control coatings (TCC's) have been widely used to tune the thermal equilibrium of spacecraft surfaces since 1970s. Development of new TCC's with improved thermo-physical properties and radiation hardness are essential to the space assets that fly in harsh environments. Herein, we fabricated calcium orthophosphate based inorganic white paint, which possess relative low solar absorptance (α s ) of 0.095 and thermal emittance (ε H ) of 0.88. Noticeably, the Ca 3 (PO 4 ) 2 coating shows excellent space radiation tolerance and thermal control capacity. After performing 90 keV proton irradiation at a fluence of 4×10 15 cm -2 , the α s of ZnO coating increases from 0.160 to 0.213 while the Ca 3 (PO 4 ) 2 coating rises from 0.095 to 0112, which only degrades one third (0.017) of the ZnO coating (0.053). Furthermore, after performing simulated solar irradiation test, the surface temperature of Ca 3 (PO 4 ) 2 paint is 14.4 °C lower than that of ZnO coating, evidencing its prominent thermal-optical performance. Besides, we also found that Ga 2 O 3 based liquid-glass white paint is a good candidate for thermal equilibrium of spacecraft.
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高影响因子
Science China-Materials
·
2024
·
IF 6.8
Wei Yi,Song Menglin,Li Lihua,Ma Yingjin,Lao Xinyue,Liu Yuan,Li Guogang,Hao Jianhua
Persistent luminescence nanomaterials can remain luminescence when the light source is turned off, which exhibits promise in biosensor and bioimaging fields since they have the ability to completely eradicate tissue autofluorescence. Although significant progress has been made in the persistent luminescence biosensing, there is still a dearth of long-afterglow detection platform with low limit of detection (LOD) and high sensitivity. Herein, Zn 2 GeO 4 :Mn, Cr persistently luminescent nanorods (PLNRs) with superior persistent luminescence and long afterglow time were developed. The addition of Cr 3+ manifestly improves persistent luminescence intensity and afterglow duration through creating a deep defect trap. Then the biosensors were constructed by combining the Zn 2 GeO 4 :Mn,Cr PLNRs-antibody and Fe 3 O 4 magnetic nanoparticles (MNPs)-antibody for nucleocapsid protein detection based on electrostatic attraction. The LOD value for nucleocapsid protein realizes as low as 39.82 ag/mL, which is much lower than the previously reported persistent luminescent-based biosensors. Accordingly, the low detection sensitivity is attributed to fluorescence resonance energy transfer. In addition, high specificity is also achieved. Therefore, the as-prepared Zn 2 GeO 4 :Mn,Cr persistently luminescent materials can act as the promising candidate in biosensors applications. This strategy provides effective guidance for the development of biosensing platforms with high sensitivity and specificity.
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高影响因子
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