CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Shan Gao,Haidong Yu,Peng Yang,Yuewen Zhang,Hongan Ma,Xiaopeng Jia
Composites consisting of two nano-or molecular-scale components tend to exhibit newer properties or characterizations compared to the matrix material. However, they are extremely limited in thermoelectricity due to the difficulty of achieving an extremely homogeneous distribution of the material on such a small scale. In this paper, we successfully prepared a series of composite thermoelectric materials of Sr 0.9 La 0.1 Ti 0.85 Nb 0.15 O 3 /carbon nanotubes (CNTs, with contents of 0.5, 1.5, 2.5, and 5.0 wt%). Highly homogeneous dispersion of CNTs was observed in the strontium titanate oxide (SrTiO 3 ) matrix prepared via high-temperature and high-pressure (HPHT) synthesis due to the interaction between SrTiO 3 and multi-walled CNTs. The experimental results showed that CNTs were uniformly dispersed in the composite powders synthesized using the HPHT method. Meanwhile, the electrical conductivity increased linearly with the increase in the CNTs content. The power factor reached 684 μWm −1 K −2 at 973K with 2.5 wt% CNTs composite concentration. This considerable enhancement is attributed to the increase in the charge carrier concentration as well as the higher electron mobility. In addition, the lattice thermal conductivity was suppressed due to enhanced Umklapp scattering. This ultimately leads to a thermoelectric figure of merit, zT , of 0.33 at 973 K. This work opens a new window on the thermoelectric properties of nanocomposite SrTiO 3 -based thermoelectric materials.
研究领域:
材料科学
·
热电学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2012
·Vol. 17
·期 4
·987-992
·
IF 2.131
Geng Xiuyu,Rao Mumin,Li Xiaoping,Li Weishan
A facile method is developed for homogeneous dispersion of sulfur (S) nanoparticles in multi-walled carbon nanotubes (MWCNTs). The process involves the modification of MWCNTs via oxidation catalyzed by acid and the introduction of sulfur nanoparticles into the MWCNTs through direct precipitation. The resulting sample (precipitated S/MWCNTs) is characterized with scanning electron microscopy and thermogravimetric analysis, and its performance as cathode of lithium/sulfur battery is investigated with a comparison of the sample prepared by ball-milling (ball-milling S/MWCNTs). It is found that the precipitated S/MWCNTs exhibit better battery performance than the ball-milling S/MWCNTs. The initial discharge capacity is 1,299 mA h g −1 for the precipitated S/MWCNTs but only 839 mA h g −1 for ball-milling S/MWCNTs at 0.02 C. The capacity remains 800 mA h g −1 for the precipitated S/MWCNTs but only 620 mA h g −1 for ball-milling S/MWCNTs at 0.05 C after 50 cycles. The better performance of the precipitated S/MWCNTs results from the improved uniformity of S dispersed in MWCNTs through precipitation.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2025
·
IF 12.5
Xin Wang,Pan Jiang,Xinjian Dai,Hao Guan,Xiaoqing Wang
Developing high-performance metal-organic framework (MOF)-based composites with high loading and uniform distribution of MOF nanoparticles is crucial for their adsorption-associated applications but remains challenging due to the lack of ideal carriers. Herein, a novel MOF-based composite was developed by in situ growth of MIL-53(Al) crystals within the carboxylated wood sponge (CWS) derived from natural balsa wood. The conversion of the cellular structure of natural wood into a lamellar structure greatly enhances the accessibility of the wood scaffold, while the introduction of carboxyl groups onto the cellulose skeleton of the wood sponge encourages the selective growth of MIL-53(Al) crystals on the lamellae of CWS. The structural features of the obtained MIL-53(Al)@CWS were investigated with FT-IR, XRD, SEM, and N 2 adsorption/desorption isotherms. The MIL-53(Al) loading can be finely tuned by adjusting the concentration of the MOF precursor solutions, and an appropriate MIL-53(Al) loading of 23 wt% results in the uniform dispersion of MIL-53(Al) crystals within the wood sponge without agglomeration. Benefiting from the high loading of MIL-53(Al) and the unique lamellar channels of CWS, the developed MIL-53(Al)@CWS can effectively adsorb various organic dyes such as rhodamine B (RhB), methylene blue, Congo red, and methyl orange in water, with a high adsorption capacity of 135.82 mg g −1 for RhB. Density functional theory (DFT) calculations reveal the detailed dynamic diffusion pathways and the molecular interactions between RhB and MIL-53(Al). This work demonstrates the advantages and potentials of lamellar wood sponges as a promising host matrix in supporting MOF powders for adsorption-associated applications.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
STAR Protocols
·
2022
·
IF 0
Haocheng Wu,Yi Zhu,Rongrong Jia,Liyi Shi,Lei Huang
Summary Controlling the size and uniform dispersion of noble metal nanoclusters on the metal oxide based semiconductor are difficult due to the natural tendency for metal atoms to agglomerate. Here, we present the protocol for an “irradiation-dark” photochemical deposition to obtain uniform metal nanoclusters on semiconductor support, and the protocol for measuring the size and size distribution of metal nanoclusters. For complete details on the use and execution of this protocol, please refer to Wu et al. (2022) .
研究领域:
材料科学
·
化学
✓ 已验证
DOI
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Caili Xu,Qi Wang,Rong Ding,Yi Wang,Yun Zhang,Guangyin Fan
Metal phosphides (MPs) synthesized by solid-state reaction have shown considerable potential in hydrogen evolution reaction (HER) from water splitting compared with that of Pt. However, large-sized MP nanoparticles (NPs) with irregular morphologies are inevitably achieved via the solid-state reaction with high-temperature calcination, which lead to the reduced availability of the active sites. Here, a simple and straightforward strategy was developed to synthesize monodispersed, uniformly distributed, and small Rh x P NPs decorated on phosphorus-doped nitride carbon (PNC) via the pyrolysis of rhodium(Ш) chloride, triphenylphosphine , and melamine (Rh x P/PNC-m). The Rh x P/PNC-m that served as a HER electrocatalyst displayed excellent performance with the overpotentials of 24 and 27 mV at 10 mA cm −2 in basic and acidic solutions, respectively. This catalyst also showed good long-term stability in both media. The high-performance of Rh x P/PNC-m should be attributed to the small, monodispersed, and highly distributed Rh x P NPs on PNC support, which can supply abundant catalytically active sites for HER. The developed strategy for the synthesis of small Rh x P NPs may offer new opportunities toward the electrochemical applications of other metal phosphides.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Zhaojin Li,Conghao Shi,Pengfei Liu,Yunbo Di,Di Zhang,Qiujun Wang,Huilan Sun,Qujiang Sun,Bo Wang
At present, silicon/graphite composite is the most promising anode material for high energy density lithium-ion batteries. However, during the preparation, nanoscale silicon will inevitably undergo agglomeration, which will cause serious volume changes and breakage during the charging/discharging process. How to achieve uniform dispersion of nanoscale silicon onto the surface of graphite becomes a great challenge. Here, by grafting functional groups on the surface of silicon, both the repulsive force between silicon particles and the binding force between silicon/graphite have been improved, thereby highly uniform dispersed silicon is achieved. After being coated with asphalt and etching off the functional groups, the conductivity and ion migration ability of the composite are further improved. Resultantly, the modified composite provides a high discharging capacity of 598.4 mAh·g −1 at 0.2C and can still maintain a high-capacity retention of 90.7 % and a small volume expansion rate of 30.8 % after 500 cycles.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Lin Chen,Huibo Wang,Chengzhan Liu,Xianchun Liu,Shuangxi Xing
Highly dispersible copper nanoparticles (CuNPs) anchoring on the N-doped carbon films are achieved by pyrolyzing urea, citric acid and copper nitrate in one pot. The presence of the CuNPs and the N-doped carbon film is investigated by transmission electron microscopic, X-ray diffraction, X-ray photoelectron and Raman spectra. The citric acid is used as a carbon source to support the as-synthesized CuNPs and the urea takes a role as a nitrogen source to dope into the carbon structure and localize the CuNPs with a separated state. Such an N-doped carbon film with well-dispersed CuNPs on its surface presents an excellent catalytic performance and stability via using the reduction of 4-nitrophenol by NaBH 4 as a model reaction.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Small
·
2024
·
IF 13
Yaping Wang,Xirui Wang,Han Yi,Linping Yan,Xuepin Liao,Bi Shi
Advanced X- and γ-ray-shielding materials are conventionally designed and fabricated via the uniform dispersion of high-Z elements into the substrate. These soluble high-Z elements considerably reduced the particle size of functional components; however, the as-obtained composites exhibited weak absorption region at 40–80 keV and poor water resistance. To address these issues, such materials are fabricated by introducing cerium and tungsten into regenerated collagen fibers (RCFs) using a “dual impregnation–desolvation” strategy. The uniform dispersion of functional components is achieved via the in situ generation of cerium–tungsten nanoparticles (CeW NPs) under multiple impregnating and desolvating cycles; as a result, the CeW NPs achieved an ultrasmall particle size of 17.15 nm. Benefiting from the ultrasmall particle size and uniform dispersion of CeW NPs, the fabricated CeW-RCF composites exhibit satisfactory X- and γ-ray-shielding capabilities with an ultrahigh mass attenuation coefficient (MAC) of 5.9 cm 2 g −1 at 83 keV, higher than that of lead plates. The CeW-RCF composites also exhibit outstanding mechanical strength, low density, and high air permeability, demonstrating their superior wearability. This work provides novel insights into the design and fabrication of advanced X- and γ-ray-shielding materials with high radiation-shielding performance and enhanced wearability.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Carbon Letters
·
2024
·Vol. 34
·期 2
·603-609
·
IF 5.5
Mai Xuan-Dung,Bui Thi-Thu,Tran Dai-Luat,Mai Van-Tuan,Duong Ngoc-Huyen,Nguyen Van-Hao
Composites of carbon quantum dots (CQDs) are important materials to utilize the optical properties of CQDs in diverse applications including photoluminescence-based sensing and LED phosphors. Combining pre-prepared CQDs with a polymeric matrix usually causes changes in the optical properties of CQDs due to unavoidable aggregation. Recently, the preparation of composites based on in-situ formed CQDs has been debated to overcome the aggregation limits of the conventional mixing methods. Herein, we have demonstrated the synthesis of homogeneous CQDs composites by simple thermal annealing blends of aluminum hydroxide (AlOH), citric acid (CA), and urea (URA). Transmission electron microscopy (TEM), X-ray diffraction, and Raman spectroscopy studies revealed the formation of individual CQDs with a diameter of about 2–9 nm dispersed homogeneously over the AlOH matrix. The composites have a broad excitation band centered at about 360 nm and exhibit excitation-dependent photoluminescence which was similar to that of hydrothermally synthesized CQDs from CA and URA. The photoluminescent intensity of the composite was stable to UV irradiation and responded selectively to Cu(II) ion demonstrating its potential application in Cu(II) sensing.
研究领域:
材料科学
·
纳米技术
·
分析化学
·
光学传感
✓ 已验证
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2024
·
IF 6.2
Hegeng Wei,Zexi Zhang,Zebo Li,Linfeng Peng,Guannan Yang,Tianshuo Zhao,Yu Zhang,Guanghan Huang,Chengqiang Cui
Graphene and its derivatives have excellent thermal conductivity, and are common additives for metal-based nanocomposites. However, the easy aggregation of graphene and metal nanoparticles severely limits uniform mixing, and hinders development and performance improvement of metal/graphene composites. Herein, we developed a dual-dispersion medium method to fabricate a silver–graphene oxide (Ag/GO) composite with high thermal/electrical conductivity and mechanical performance. Through the method, GO and silver particles are dispersed evenly in different media and then fully mixed, thereby GO sheets can be uniformly dispersed and form a network in the matrix of silver particles. By adding a low GO content of 0.2 wt%, the density of the sintered Ag/GO joint increased from 9.0 to 9.5 g/cm 3 , the shear strength increased from 45.8 to 71.9 MPa, the thermal conductivity increased from 234.2 to 375.2 W/(m·K), and the electrical resistivity reduced from 4.6 to 1.9 μΩ cm. The added GO sheets form a coating layer with good interfacial bonding on the surface of most silver particles and form a uniform network in the Ag matrix. In addition, the added GO sheets reduce the overall thermal expansion coefficient and agglomerate size, thereby improving the sintering density and heat transfer efficiency of the Ag/GO composite. Because of its comprehensive properties, the Ag/GO composite material in this study exhibits good potential as a heat dissipation material for packaging and interconnect applications of high-power-density electronic devices.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2015
·
IF 2.567
Rongrong Jiang,Xufeng Zhou,Qile Fang,Zhaoping Liu
Graphene nanosheets have shown great potential in enhancing the strength of metal composites. In previous researches, reduced graphene oxide (rGO) are usually used as the additive. Here, we demonstrate that pristine graphene (PG) prepared by intercalation and exfoliation of graphite, with negligible oxygen-containing functional groups, much less defects and higher electrical conductivity than rGO, exhibits better performance than rGO as additives for the enhancement of the strength of metal composites. Surface modification of PG and Cu was conducted to enhance the interaction between two components, resulting in homogeneous distribution of PG in Cu matrix. The PG/Cu composite exhibits yield strength σ 0.2 and 5% compression strength up to 172 and 228 MPa, respectively, which is a 90% and 81% promotion comparing to pure Cu, while its electrical conductivity still stays at 84.2% IACS. As to rGO/Cu composite, yield strength σ 0.2 and 5% compression strength is 156 and 208 MPa, respectively, and its electrical conductivity is 73.4% IASC. Such significant improvement on strength can be explained by the two-dimensional geometry and high crystallinity of PG whose high strength and modulus effectively constrain the movement of dislocations.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2021
·
IF 7.328
Xiaohao Sun,Xiao Yu,Wei Li,Minfang Chen,Debao Liu
The development of biodegradable Zn matrix composites has been considered a promising approach to achieving enhanced mechanical properties, controllable degradation rate, good biocompatibility, and good osseointegration as orthopedic implants. However, scant literature regarding Zn matrix composites has been reported because of the great difficulty in dispersing the nano-sized bioactive reinforcements uniformly within the Zn matrix. In the present study, a novel and effective method were employed to obtain Zn matrix composites reinforced by uniformly dispersed beta-tricalcium phosphate (β-TCP) via graphene oxide (GO)-assisted hetero-agglomeration and subsequent spark plasma sintering process. A very low-content (0.04 vol%) few-layered GO was used as a coupling reagent to connect the Zn matrix and nano-sized TCP particles. In an appropriate polarity solvent, the negatively charged GO sheets could combine with both the positively charged Zn powder and TCP particles by electrostatic attraction and charge neutralization. Due to the nature of hetero-agglomeration, the flexible GO sheet could adhere to the large Zn powder and attracted a certain amount of TCP particles to form a Zn/GO/TCP sandwich structure by charge neutralization thereby forming a uniform dispersion of TCP particles within Zn matrix. After the spark plasma sintering (SPS) process, the TCP particles incorporated with very thin ZnO layers (thickness of a few dozen nanometers) formed a homogeneous and unique 3D network-like distribution in as-sintered TCP/Zn composites. A unique “snap pea”-like structure was confirmed at the grain boundary of α-Zn grains, which consisted of the TCP particles as “pea” and thin ZnO layer as “pod”. Due to the uniform dispersion of bioactive TCP particles and unique structure of the TCP incorporating grain boundary, as-sintered 3TCP/Zn matrix composites possessed yield strength (YS) of 140.8 ± 7.7 MPa, failure strain of 36.0 ± 2.8%, the moderate degradation rate of 19.1 ± 3.3 μm·y −1 and good cytocompatibility to MC3T3-E1 cells. Moreover, osteogenic differentiation activity evaluation revealed that the addition of TCP could significantly improve the expressions of the osteogenic differentiation-related gene (ALP) in MC3T3-E1 cells, thereby resulting in improved osteogenic capability. Therefore, biodegradable 3TCP/Zn matrix composites fabricated by GO-assisted hetero-agglomeration and subsequent SPS process could be a promising material as orthopedic implants.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）