JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 1
·1-8
·
IF 2.8
Ma Jianli,Zhang Yu,Chen Chen,She Yubin
An efficient reaction sintering process is engaged to synthesize a series of non-stoichiometric Li 2(1+ x ) Mg 3 TiO 6 ( x = 0.01, 0.02, 0.03, 0.04) microwave dielectric ceramics. The single phase of Li 2 Mg 3 TiO 6 with rock-salt structure is accurately recognized by XRD. Pores left on the surface and inside the sample can be clearly observed from SEM pictures. Excessive Li + affects the local charge distribution, which influences the response of the dielectric material to the electric field. The pores are not the same medium as the matrix material, and the signal is refracted and scattered when it passes through the pores. Refractions and scatterings increase the signal transmission distance and also increase the transmission loss. These residual Li + and pores eventually affect the dielectric properties as well. Finally, at x = 0.02 and a sintering temperature of 1260 °C, the ceramic samples showed good dielectric properties: ε r = 10.983, Q×f = 107,367 GHz and τ f = − 24.2 ppm/°C.
研究领域:
材料科学
·
陶瓷材料
·
微波介质
·
固态物理
·
X射线衍射
·
扫描电子显微镜
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Danna Shan,Yan Shi,Bin Zhou,Zilin Liu,Liu Yang,Xuetao Zhu,Qishi Luo,Guanghe Li
A simple and convenient method was used to prepare a novel granular half wrapping-structured amendment (HWA) for stabilization of both cationic and anionic heavy metals. By coating Ca(OH) 2 with silicate minerals to obtain the core-coating wrapping balls, followed by drying and mixing with FeSO 4 , the final HWA effectively prevented the reaction of FeSO 4 with Ca(OH) 2 and exihibited high stabilization of arsenic (As) and cadmium (Cd) in the contaminated soils simultaneously and continuously. XRD, FTIR and SEM characterization showed that Ca(OH) 2 was successfully wrapped by zeolite without changing their chemical properties. The amendment illustrated relatively fast stabilization for As and Cd, and the stabilization rate by HMA prepared at FeSO 4 ·7H 2 O: zeolite: Ca(OH) 2 = 6.5:1:1 was 95.5% for As and 94.6% for Cd, much higher than the compound material (CM) which had side effect on Cd stabilization. In the effect of storage time experiment, when HWA was stored from 0 day to 365 days, the stabilization rate of As and Cd by HWA just decreased 3.4% and 4.3%, respectively. While the addition of CM to the soil reduced the As stabilization rate from 91.1% to 87.1% and the Cd stabilization rate was reduced from −139.8% to −223.1%. The long-term soil stabilization study demonstrated that HWA could decrease the concentration of extricable As and Cd simultaneously and continuously for 365 days without notable changes in soil pH. This research develops an easy method to synthesize granular HWA for the stabilization of cationic and anionic heavy metals from the actual contaminated soils.
研究领域:
环境科学
·
土壤化学
·
污染控制
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Junjun Wang,Peng Lin,Weiyang Yu,Peng Xu,Bowen Zhang,Guohua Cao
Pt-loaded curling-like Bi 2 WO 6 (BWO) microdiscs were fabricated via a simple one-step hydrothermal and impregnation route. Various characterization methods, such as XRD, EDS and TEM, were conducted to prove the successful Pt loading. Electron migration from the semiconductor BWO to the precious metal Pt was revealed by the blue shift of the Bi 4f and W 4f XPS peaks with the increase of the Pt loading amount and the ∼10-fold baseline resistance elevation of the BWO-based sensor by the Pt loading, proving the formation of Schottky junction. Among the pristine BWO and Pt-loaded BWO with different Pt loading amounts, 1 wt % Pt-loaded BWO exhibits the highest gas response of 209 in sensing 500 ppm triethylamine at 300 °C, a minimal selectivity coefficient of 130.6 against some typical interfering gases at the same concentration and a low detection threshold of 1 ppm. Additionally, the sensitization mechanism is discussed as the synergistic effect of noble metal catalytic effect and metal-semiconductor junctions.
研究领域:
材料科学
·
化学传感器
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Weidong Li,Qiuyi Chen,Dongyun Zhang,Chen Fang,Song Nian,Wenxu Wang,Cong Xu,Chengkang Chang
Aiming for promoting the capacity and cycling stability of O3-type NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NFM), the cathode material of sodium ion batteries (SIBs) with the most potential for industrialization, Na(Ni 1/3 Fe 1/3 Mn 1/3 ) 0.99 Mo 0.01 O 1.99 F 0.01 (NFM-MoF), Na(Ni 1/3 Fe 1/3 Mn 1/3 ) 0.99 Mo 0.01 O 2 (NFM-Mo) and NaNi 1/3 Fe 1/3 Mn 1/3 O 1.99 F 0.01 (NFM-F) were successfully synthesized by solid phase method. The electrochemical performance of the doped samples was compared with that of the pristine NFM. The mechanism of the single- or dual-doping was explored by XRD Rietveld refinement and XPS. The NFM-MoF exhibits the highest initial specific discharge capacity of 137mAhg −1 at 1 C with a retention of 91.97% after 100 cycles and the smallest polarization (0.32 V), which could be contributed to the highest Ni 2+ content and highest D Na + (7.335 ×10 −13 cm 2 ·s −1 ) caused by the synergistic effect of Mo and F dual-doping. The highest Fe 3+ content in the NFM-Mo leads to the higher initial discharge capacity of 1 36 mAhg −1 at 1 C with a relative lower retention of 83.38%, which is due to the structure instability resulting from Fe migration and the lowest Mn content, than that of the NFM-F (85.31%). It illustrates that the Mn 4+ plays a crucial role in stabilizing the structure during Na + migrating. The superiority of the discharge capacity of the NFM-Mo become narrow with rates rise, due to its lower D Na + (4.229 ×10 −13 cm 2 ·s −1 ) than that of the NFM-F D Na + (5.681 ×10 −13 cm 2 ·s −1 ). It verifies that it is a diffusion control process at high rates. Mo and F dual-doping in NFM was proved to amplify the benefit of Ni 2+ increasing, meanwhile restrain undesirable Fe increasing due to the synergistic effect.
研究领域:
材料科学
·
电化学
·
储能技术
·
无机化学
·
固体物理
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Xiaojuan Lu,Feng Zhang,Jing Li
Perovskite-type lithium-ion conductor Li 0.33 La 0.56 TiO 3 was prepared via microwave sintering. The influence of lithium sources on the properties of the samples prepared and the compensation of lithium loss were investigated. XRD patterns, exhibiting a mixture of tetragonal and cubic phase, were all similar for the samples made with different lithium sources. The total conductivity of the sample made with Li 2 CO 3 achieved 0.51 × 10 −4 S/cm, which was the highest among all the samples made with different sources. The highest total conductivity of the sample made with Li 2 CO 3 was attributed to the largest grains, which would result in a smaller concentration of less-conductive grain boundaries. The total conductivity of the sample compensated with 5% Li 2 O was 38% higher than the sample made stoichiometrically. Given that grain sizes were similar for the samples compensated with a varied amount of Li 2 O and the relative density of the sample compensated with 5% Li 2 O was even the lowest among these samples, the highest total conductivity was rooted in the highest ratio of cubic phase. These results indicated that lithium sources could influence the properties of the LLTO samples greatly by resulting in a variation on crystalline phase, grain size, and relative density, which collectively determine the migration of lithium ions in polycrystalline Li 0.33 La 0.56 TiO 3 .
研究领域:
材料科学
·
固体化学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Xiangchao Zhao,Yuansong Luo,Xiujian Zhao
NASICON-type solid electrolyte Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) has become an excellent substitute for organic liquid electrolytes due to its high ionic conductivity and exceptional air stability. However, its application is limited by its poor sintering characteristics and high grain boundary resistance. In this study, TeO 2 was introduced into LATP as a sintering aid to promote its sintering, and its properties were measured by XRD , SEM, XPS, EIS and dilatometry . The results show that the addition of TeO 2 can form eutectic liquid phase in LATP ceramic pellets during sintering, thus effectively promoting particle sintering. Not only the grain size was greatly increased, but also grain boundary and pore defects were reduced. With the help of TeO 2 , the performance of LATP is greatly improved when sintered at only 750 °C, the relative density and total ionic conductivity reached 90.64% and 0.207 mS/cm, respectively. The highest total ionic conductivity of 0.279 mS/cm and the highest relative density of 93.81% were obtained when sintered at 800 ℃ and 950 ℃, respectively. However, due to the volatilization of Li and Te at high temperature, the relative density and total ionic conductivity of LATP with TeO 2 added sintered at high temperature have only a small increase compared to that without addition. In conclusion, this study provides a feasible scheme for improving LATP performance.
研究领域:
材料科学
·
电化学
·
固体物理
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2020
·
IF 2.369
Dandan Gao,Dongdong Li,Bin Hu,Wu Li
A temperature-dependent thermodynamic model was developed for representing the solid–aqueous equilibria in the quaternary NaCl + KCl + RbCl + H2O system based on the previous ones for binary and ternary systems. The solid–liquid equilibria in the quaternary system were first predicted by the developed model and then verified by conducting the experiments at T = 298.15 K by an isothermal equilibrium method with equilibration times of 5 and 160 days, respectively. The predicted univariant curve saturated with NaCl(cr) and (K,Rb)Cl(ss) in the system is in good agreement with our experimental data. Moreover, to verify the reliability of the model for the prediction of solid solution composition that coexisted with NaCl(cr), the XRD quantitative analysis technique based on the inverse Vegard approach is used. The experimentally determined solid solution compositions well support the results predicted by the model, indicating that the model can simultaneously predict the compositions of aqueous solution and solid solution that coexisted with a pure salt, i.e., NaCl(cr), in a system under an equilibrium state. Finally, phase diagrams of the quaternary NaCl + KCl + RbCl + H2O system at a temperature range of 273.15–373.15 K were predicted. These diagrams are useful for the future industrial applications.
研究领域:
物理化学
·
热力学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Sustainable Energy & Fuels
·
2019
·Vol. 4
·期 4
·1621-1629
·
IF 4.912
Yachao Du,Qingwen Tian,Jin Huang,Yuechao Zhao,Xiaohuan Chang,Afei Zhang,Sixin Wu
Additional elements in Cu2ZnSn(S,Se)4 (CZTSSe) absorber layers present a viable strategy to improve the performance of thin film solar cells. In this study, heterovalent cation doping by partially substituting metal cations with Ga3+ is explored by constructing a sandwich-like configuration. We demonstrated that a low doping level of Ga3+ can be successfully incorporated into the host lattice of CZTSSe to form a homogeneous Cu2ZnSn(Ga) (S,Se)4 (CZTGSSe) alloy material. Characterization was performed using SEM, EDS, XRD, Raman spectroscopy, and XPS, which showed that the material fabricated by this heterovalent cation doping method expressed high phase purity, appropriate valence components, and suitable optical bandgap, which are vital for high performance solar cells. As a result, the champion device achieves stabilized efficiency as high as 10.80%, improved by nearly 28% compared with only 8.43% for the reference device.
研究领域:
材料科学
·
太阳能
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·
IF 2.7
Qihong Xue,Zhikui Jiang,Chao Wang,Xian Kan,Jiaming Wang,Jiangang Chen
13-Ni/ZrO2, 13-Ni3P/ZrO2, 13-Ni/SiO2, and 13-Ni3P/SiO2 catalysts were used in the hydrogenation of diethyl oxalate (DEO) to ethyl glycolate (Egly) to investigate the modulating effect of phosphorus. XRD, TEM and FT-IR results show that phosphorus act as a divider of Ni metallic particle and shows a segregation effect. The presence of P transformed the linkage of surface metals from the original -Ni-Ni-Ni-Ni- to the P-Ni-P-Ni-P state, and FT-IR shows that the former adsorbed CO in a combination of linear and bridging adsorption mode, whereas the latter predominantly in CO linear adsorption. Bridging adsorption is via dual sites and makes the preliminary hydrogenation products less likely to detach from the catalyst surface thus facilitating deep hydrogenation, while linear adsorption facilitates partial hydrogenation by a rapid detachment of intermediate product like Egly. The various loading Ni3P/SiO2 catalysts show incomplete phosphorylation with increasing nickel loading, giving rise to a state of coexistence of Ni and Ni3P crystalline phases. This may lead to a coexistence of surface -Ni-Ni-Ni-Ni- and P-Ni-P-Ni-P and the corresponding assort of adsorption, e.g. bridging/linear ones, making deep hydrogenation occur partially besides stepwise hydrogenation.
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wei Zhou,Wenwei Zhang,Xueqin Ma,Haichen Lai,Xingguang Zhang
Metal-zeolites catalysts are of great importance in selective organic conversions. Zeolites possess features of highly-ordered porous network, adjustable acidic properties (Brønsted/Lewis), spatial nanoconfinement effects, unique shape selectivity and the strong (hydrothermal-) stability. The role of zeolite hydroxyl (z-OH) groups, such as bridging ones in Si-O(H)-Al (B acids) and terminal ones in Al-OH and Si-OH (silanols), in catalysis is an interesting topic, particularly when they are not catalytic active sites, while they affect the catalytic performances. This study comprehensively investigated series of Au/USY catalysts in the selective oxidation of benzyl alcohol to benzaldehyde and clarified the dominating contributions of Al-associated z-OH groups to affecting catalytic conversions and selectivity via altering the Si/Al ratio and reducing z-OH groups by amorphous silica species derived from diethoxydimethylsilane under high-temperature calcination. The catalysts were characterized by XRD, BET, TEM, XPS, UV/Vis, FT-IR and in-situ DRIFT to investigate crystal structures, textural properties, morphologies, size distribution, chemical state of gold, acidity, and adsorptive properties. The experimental results proved that zeolites with a higher amount of z-OH groups tuned by Si/Al ratios or by diethoxydimethylsilane silylation exhibited higher catalytic activity because of the adsorption effect. Finally, a possible mechanism was discussed based on the experimental results and literature.
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yuezhen Mao,Rongna Chen,Huanhuan You,Yang Liu,Sunrui Luan,Li Hou,Faming Gao
Antimony-based anodes possessing advantages of stable operating voltage and high theoretical capacity can replace graphene as alloy-based electrodes material in LIBs applications. However, the problems of capacity decaying and poor stability of Sb-based materials due to volume expansion and structural crushing during the long-term cycling remain to be solved. Therefore, we propose a strategy of using S and N co-doped carbon nanofibers encapsulated with Sb nanoparticles to overcome the above problems. The proposed material exhibits an excellent lithium storage performance with a high reversible specific capacity of 734 mAh g −1 at 0.1 A g −1 after 50 cycles (474.8 mAh g −1 at 1 A g −1 after 800 cycles, 394.5 mAh g −1 at 2 A g −1 after 2000 cycles). Importantly, a specific capacity of 288.5 mAh g −1 remains after more than 5000 cycles. The superior electrochemical performance of the S and N co-doped electrode is attributed to the proven structure and stability of the carbon matrix alleviating the volume changes of Sb during the process of lithium intercalation and extraction. The alloying/de-alloying reactions of the S@Sb@N-CNFs composite in the first charging/discharging process were systematically investigated by ex-situ XRD . This strategy of S and N co-doped carbon matrix could establish Sb-based materials as potential high-performance anodes for LIBs.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Debao Liu,Baolu Shi,Chenqi Wang,Zeshuai Li,Xianbo Wang,Baosheng Xu,Lijie Qu
Herein, the SiC ceramic aerogels with in-situ growth of SiC nanowires (SiC w /SiC CAs) have been synthesized by polymer‐derived ceramics (PDCs) method. The morphology, microstructure, and phase composition of the as-prepared samples were systematically investigated through SEM, XRD , TEM , Raman spectrum, FT-IR spectrum, and XPS spectrum techniques. The results showed that the as-obtained SiC w has a diameter of about 80 nm and a length of 1–3.5 μm. In addition, the formation mechanism and evolution process of growth SiC w were systematically studied using a VLS growth mechanisms. The way in this work could be expanded to synthesize other Si-based porous ceramic aerogel nanostructed with nanowires.
研究领域:
材料科学
·
纳米技术
·
陶瓷
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）