Small
·
2023
·Vol. 20
·期 3
·2306251
·
IF 13.3
Muchun Guo,Ming Liu,Jianbo Zhu,Yuke Zhu,Fengkai Guo,Wei Cai,Yongsheng Zhang,QinYong Zhang,Jiehe Sui
Chemical bonds determine electron and phonon transport in solids. Tailoring chemical bonding in thermoelectric materials causes desirable or compromise thermoelectric transport properties. In this work, taking an example of CaMg 2 Bi 2 with covalent and ionic bonds, density functional theory calculations uncover that element Zn, respectively, replacing Ca and Mg sites cause the weakness of ionic and covalent bonding. Electrically, Zn doping at both Ca and Mg sites increases carrier concentration, while the former leads to higher carrier concentration than that of the latter because of its lower vacancy formation energy. Both doping types increase density-of-state effective mass but their mechanisms are different. The Zn doping Ca site induces resonance level in valence band and Zn doping Mg site promotes orbital alignment. Thermally, point defect and the change of phonon dispersion introduced by doping result in pronounced reduction of lattice thermal conductivity. Finally, combining with the further increase of carrier concentration caused by Na doping and the modulation of band structure and the decrease of lattice thermal conductivity caused by Ba doping, a high figure-of-merit ZT of 1.1 at 823 K in Zn doping Ca sample is realized, which is competitive in 1–2–2 Zintl phase thermoelectric systems.
研究领域:
材料科学
·
凝聚态物理
·
无机化学
·
能源材料
·
热电转换
✓ 已验证
DOI
高影响因子
FUEL
·
2017
·
IF 4.601
Junliang Wang,Shuyan Zhou,Ke Bei,I-Ming Chou,Chunmian Lin,Zhiyan Pan
This work developed a new method for measuring the volume expansion of a CO 2 + n -dodecane mixture, using a fused silica capillary cell (FSCC), combined with a heating-cooling stage and a confocal Raman spectrometer. The cell was constructed on the micron scale to reduce the temperature gradient and reagent consumption. The results confirmed the feasibility of this method that using Raman spectra to verify phase equilibrium, a digital camera to record images of the CO 2 + n -dodecane mixture and a micrometer to measure the volume, a section of water (water seal) between n -dodecane and gas phase to prevent n -dodecane from evaporating. It was shown that the volume expansion factor of the mixture increased with pressure going from 1.0 to 10.0 MPa, but decreased as the temperature was raised from 30 to 80 °C. In addition, a positive quadratic relationship ( R 2 > 0.99) was obtained between Raman peak intensity ratio and volume expansion factor, such that more volume expansion factors could be obtained according to the equations with measured Raman peak intensity ratio data. This experiment widens the ranges of temperature and pressure in the measurements of the volume expansion, and provides more volume expansion data for CO 2 -enhanced oil recovery.
研究领域:
物理化学
·
能源科学
·
油气开采
·
光谱分析
·
热力学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Yawei Song,Kuanjun Fang,Mohd Nadeem Bukhari,Kun Zhang,Zhiyuan Tang
Inkjet printability of dye-based inks including stability, jetting morphology, and color performance is difficult to maintain due to the strong dye molecular interaction. Herein, carboxyl-rich polymer nanospheres were introduced to the dye-based inks, forming a novel kind of multilayer dye/polymer nanospheres to enhance the inkjet printability. Disperse dyes were firstly loaded into poly (styrene-butyl acrylate-methacrylate) nanospheres at 95 °C, and then encapsulated by poly (styrene-methacrylate) polymer layer through seed polymerization to form multilayer structure. The results showed that hydrogen bonds were formed between disperse dyes and nanospheres, and the interaction was enhanced when more carboxyl groups were polymerized on nanosphere surface. Moreover, due to the high surface carboxyl group content, the stability was significantly improved in comparison with disperse dye suspension. After inkjet printing , the dye/nanosphere dispersion showed more stable droplet formation and higher color depth. Besides, because of the self-curing ability of polymer nanospheres, satisfactory fastness was obtained for practical application. The results from this study can promote the optimization of dye-based ink formulations, and show great potential in obtaining high quality inkjet printing products.
研究领域:
材料科学
·
高分子化学
·
表面化学
·
印刷电子学
·
功能材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 48
·期 16
·23258-23265
·
IF 5.532
Jianlong Chai,Yabin Zhu,Xing Gao,Tielong Shen,Lijuan Niu,Shufen Li,Peng Jin,Minghuan Cui,Zhiguang Wang
Al 2 O 3 /SiC ceramic composites with different SiC contents have been prepared by powder metallurgy at 1600 °C for 120 min at 30 MPa pressure. The effect of second phase particles on the microstructure and mechanical properties of composites have been studied. The results show that SiC particle has a significant impact on the matrix subjected to residual stress, and on the microstructure of the composites as well. The average grain size of alumina matrix decreases as the SiC particle content increases. Simultaneously, it has been found that the mechanical properties of the material are significantly enhanced in comparison with monolithic Al 2 O 3 . The highest strength and toughness are obtained when the SiC content is 15 vol%, and the values are 1237 MPa and 5.68 MPa m 1/2 , respectively. The mechanisms of strengthening and toughening have been discussed.
研究领域:
材料科学
·
陶瓷学
·
复合材料工程
·
固态物理
·
粉末冶金
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2019
·Vol. 12
·期 4
·858-865
·
IF 7.804
Xinxin Li,Qingshan Zhao,Xiang Feng,Lei Pan,Zhuangzhuang Wu,Xiaocui Wu,Tianwen Ma,Jialiang Liu,Yuanyuan Pan,Yan Song,Mingbo Wu
Graphical Nitrogen-doped graphene nanoshells supporting palladium nanoparticles (Pd/N-GNS) have been developed as a superior catalyst for the N -allylation reaction. Experimental results and DFT calculations reveal strong metal–support interactions between the pyridinic N and palladium species, which significantly boost the catalytic efficiency and stability of the catalyst. In this study, nitrogen-doped graphene nanoshells (N-GNS) were developed to support palladium nanoparticles (Pd/N-GNS) as an efficient and recyclable catalyst for the N -allylation reaction. N-GNS was synthesized through a facile hard-template method by using petroleum asphalt, followed by nitrogen doping by thermal annealing with urea, the contents and species of which could be altered by the calcination temperature. Palladium nanoparticles (Pd NPs) with an average diameter of 3.3 nm were homogeneously deposited onto the N-GNS support through a mild solvent-growth approach. The Pd/N-GNS exhibited a superior activity towards the N -allylation reaction, 6-fold higher than that of the pristine graphene nanoshells supporting the palladium catalyst. The Pd/N-GNS could be recycled several times without activity deterioration and metal leaching. The catalytic activity showed a linear correlation relationship with the pyridinic N content. Experimental and theoretical studies reveal strong metal–support interactions between the pyridinic N and palladium species, which can downsize the Pd NPs, modulate the electronic properties, and promote the adsorption of reactant, thereby significantly boosting the catalytic efficiency and stability for the N -allylation process. The present work could help unravel the roles of nitrogen-doped carbon supports and provides a feasible strategy to rationally design superior palladium catalysts for chemical transformations.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 82
·52024-52029
·
IF 3.108
Xiao-Fen Sun,Zhongxia Wang,Wei-Qiang Liao,Peng-Fei Li,Jixing Gao,Yi-Yang Huang,Hai-Peng Chen,Heng-Yun Ye,Yi Zhang
In this paper, three new hybrid phase transition compounds, [Hmpy]CdBr3 (1, Hmpy = N-methylpyrrolidinuium cation), [Hmpy]2CdBr4 (2) and [Hmpy]3CdBr3·CdBr4 (3), were synthetized by means of regulating the ratio of reactants. Systematic characterizations consisting of variable temperature X-ray single crystal diffraction, differential scanning calorimetry (DSC) and dielectric measurements reveal that 1 with infinite one-dimensional (1D) [CdBr3]n− chains undergoes a phase transition around 278 K; 2 with isolated [CdBr4]2− tetrahedrons exhibits a high-temperature phase transition close to 367 K, accompanied by prominent switchable dielectric behavior. Interestingly, 1D [CdBr3]n− chains and isolated [CdBr4]2− tetrahedrons both exist in 3, associated with a phase transition at 320 K. The phase transitions in the three compounds are originated from the order-disorder transitions of the Hmpy cation. It is expected that our finding would promote the development of hybrid dielectric transition materials with adjustable properties.
研究领域:
材料化学
·
凝聚态物理
·
晶体工程
·
功能材料
·
介电材料
✓ 已验证
DOI
高影响因子
KINETICS AND CATALYSIS
·
2013
·Vol. 54
·期 6
·716-723
·
IF 0.543
Zeng Minfeng,Sun Xudong,Qi Chenze,Zhang Xian-Man
A novel and environmentally friendly heterogeneous catalyst has been prepared through the wet impregnation of copper(I) species onto the highly porous chitosan microspheres (CuI/PCMS). This novel CuI/PCMS heterogeneous catalyst with no additional ligands is much better than CuI homogeneous catalysts when applied in Heck reactions. Moreover, the reaction conditions are much milder than those for the similar copper catalysts mediated cross-coupling reactions reported in the literature. PCMS has been demonstrated not only the excellent solid support, but also have many unique functional groups to chelate the copper (I) species to enhance its catalytic activity.
研究领域:
催化化学
·
有机合成
·
材料化学
·
环境友好化学
·
功能高分子材料
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Wenbin Wu,Ping Zhang,Siqi Chen,Xiaohong Liu,Guilin Feng,Meihua Zuo,Wangyan Xing,Bin Zhang,Weifeng Fan,Heng Zhang,Ping Zhang,Jie Zhang,Wei Xiang
O3 phase layered oxides are highly attractive cathode materials for sodium-ion batteries because of their high capacity and decent initial Coulombic efficiency. However, their rate capability and long cycling life are unsatisfactory due to the narrow Na + transfer channel and irreversible phase transitions of O3 phase during sodiation/desodiation process. Constructing O3/P2 multiphase structures has been proven to be an effective strategy to overcome these challenges. In this study, we synthesized bi-phasic structured O3/P2 Na(Ni 2/9 Fe 1/3 Cu 1/9 Mn 1/3 ) 1- x Mn x O 2 ( x = 0.01, 0.02, 0.03, 0.04, 0.05) materials through Mn doping during sodiation process. Benefiting from surface P2 phase layer with the enhanced Na + transfer dynamics and high structural stability , the Na(Ni 2/9 Fe 1/3 Cu 1/9 Mn 1/3 ) 0.98 Mn 0.02 O 2 (NFCM-M2) cathode delivers a reversible capacity of 139.1 mA h g −1 at 0.1 C, and retains 71.4 % of its original capacity after 300 cycles at 1 C. Our work provides useful guidance for designing multiphase cathodes and offers new insights into the structure-performance correlation for sodium-ion cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 15
·21459-21465
·
IF 4.527
Xianwei Su,Xiaojia Shang,Yusi Che,Shaolong Li,Jianxun Song,Jilin He
Homogenous ZrC x O y powders have been successfully synthesized by in-situ electro-reduction of solid ZrO 2 –C composite precursors in molten CaCl 2 . The effect of applied cell voltage and molar ratio of ZrO 2 to C on preparation of ZrC x O y were investigated. The reduction pathway of the composite electrode was studied based on the analysis of intermediate products using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that ZrO 2 is firstly converted to CaZrO 3 . The resulting CaZrO 3 is then reduced to ZrC x O y . The ZrC x O y formation is dramatically influenced by electrolysis voltage and molar ratio of ZrO 2 to C: a higher cell voltage and lower molar ratio of the ZrO 2 to C are more preferable for the formation of ZrC x O y powder. Homogenous ZrC x O y powders with particle size of ~100 nm are synthesized by ZrO 2 /C starting elemental powders in CaCl 2 molten salt at 1123 K for more than 3 h, when the cell voltage is 3.0 V and the molar ratio of the ZrO 2 to carbon starting materials is 1:1.0.
研究领域:
材料科学
·
无机非金属材料
·
电化学合成
·
粉末冶金
·
固态化学
✓ 已验证
DOI
高影响因子
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
·
2023
·Vol. 40
·期 8
·2300032
·
IF 2.7
Hao Jiang,Chenxi Zang,Yixiu Dong,Min Lai,Shuhong Xu,Jingkun Xu
CsPbX 3 (X = Cl, Br, I) nanocrystals (NCs) are competitive materials for a wide range of applications because of their outstanding optoelectronic properties. Ion doping has been demonstrated as one powerful method for improving the optical properties of CsPbX 3 NCs. However, the conventional ion-doping approaches are tedious, and generally performed under an inert atmosphere and high temperature. In this work, a one-step ultrasonic-assisted approach is demonstrated to prepare doped CsPbX 3 NCs. To demonstrate the universality of the ultrasonic-assisted ion-doping approach, three ion-doped perovskite NCs are prepared, which represent three common improvements effects of ion doping on perovskite NCs, namely improved stability, PL emission, and photoluminescence quantum yields (PLQYs) of perovskite NCs. Sr-doped CsPbI 3 NCs showed improved phase stability. Mn-doped CsPbCl 3 NCs showed dual-color emissions at 406 and 580 nm. The PLQYs of the as-prepared Ni-doped CsPbCl 3 NCs are greatly improved, from 10.1% to 71%. Such a simple and versatile ion-doping approach may promote the practical applications of all-inorganic perovskite NCs.
研究领域:
材料科学
·
纳米技术
·
光电子学
·
无机化学
·
半导体材料
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2013
·Vol. 34
·期 12
·2161-2166
·
IF 1.304
Mingming Zhang,Manman Jiang,Changhai Liang
A basic anion exchange resin , Amberlite IRA-900, was loaded with Pd(C 3 H 5 )(C 5 H 5 ) by an easy metal-organic chemical vapor deposition (MOCVD) approach to give Pd@IRA-900 catalyst after reduction at room temperature . Ultraviolet-Visible spectroscopy results showed a red shift of the absorption peak of Pd 2+ after the Pd precursor was loaded on the resin, indicating that a chemical reaction occurred between the precursor and the support. Pd nanoparticles with 2.6 nm of average size were well dispersed on the support. The Pd@IRA-900 catalyst showed high activity for different kinds of aryl halides in Suzuki-Miyaura coupling reactions under mild and aerobic conditions. Excellent recyclability of Pd@IRA-900 catalyst was also observed in the Suzuki-Miyaura coupling reaction of iodobenzene and phenylboronic acid . A bifunctional catalyst Pd@IRA-900(OH) was synthesized by pretreating the ion exchange resin support with NaOH before Pd loading, which successfully catalyzed the Suzuki-Miyaura reaction of iodobenzene and phenylboronic acid without base under aerobic conditions.
研究领域:
催化化学
·
有机合成
·
材料化学
·
绿色化学
·
纳米催化
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2022
·
IF 4.171
Yuzhen Wang,Yanbin Li,Chaoyang Ma,Zicheng Wen,Xuanyi Yuan,Yongge Cao
In this study, NaYTiO 4 : Yb/Tm phosphors with different concentrations of Yb 3+ and Tm 3+ ions were synthesized by conventional solid-state reaction. Upon a 980 nm laser excitation, the up-conversion luminescence properties in a wide temperature range (303–823 K) were investigated. By employing the fluorescence intensity ratio (FIR) techniques based on the robust near-infrared emissions of thermally coupled 3 F 2,3 / 3 H 4 energy levels and 3 H 4(1) / 3 H 4(2) Stark energy levels, the calculated absolute sensitivity (S a ), relative sensitivity (S r ), and temperature uncertainty (δT) values demonstrated good temperature sensing properties. For the 3 F 2,3 / 3 H 4 energy levels, the maximum S r and minimum δT values are 1.04% K −1 and 0.010 K at 463 K, respectively. Moreover, the maximum S a is 0.32 × 10 −3 K −1 at 823 K. In addition, the thermally coupled 3 H 4 Stark energy levels present the maximum S a , S r and the minimum δT are 0.88 × 10 −3 K −1 , 0.60% K −1 and 3.17 K at 303 K, respectively. Besides, due to the ratio of blue to red emission varying with elevated temperature, the NaYTiO 4 : Yb/Tm phosphors are expected to be applied as an intuitive high-temperature indicator.
研究领域:
材料科学
·
光学材料
·
传感器技术
·
固体化学
·
功能材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）