ELECTROCHIMICA ACTA
·
2012
·
IF 3.832
Xiaolei Sun,Xinghui Wang,Li Qiao,Duokai Hu,Na Feng,Xiuwan Li,Yingqi Liu,Deyan He
Porous SnO 2 –Sn/C composites have been synthesized via directly pyrolysis of mixtures of SnO 2 powder and poly(vinylidene fluoride) without any surfactant addition and other treatment. The composites are composed of SnO 2 and Sn nanoparticles which are well encapsulated in porous carbon matrix as characterized by transmission electron microscopy, X-ray powder diffraction and micro-Raman spectrometer. The obtained materials were used as anode for lithium ion batteries, a discharge capacity of 1171 mAh g −1 and a charge capacity of 611 mAh g −1 were shown in the first cycle at a current density of 100 mA g −1 , and good cycling performance achieved even at current density as high as 800 mA g −1 . The good electrochemical behaviors could be attributed to the formation of Sn nanoparticles which can increase the reversible capacity and the porous carbon matrix which is of excellent buffering effect and high electronic conductivity.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
锂离子电池
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Jianbo Wu,Guoxiang Pan,Wenwu Zhong,Liang Yang,Shengjue Deng,Xinhui Xia
Controllable fabrication of advanced electrode materials is critical for the development of lithium ion batteries (LIBs). Herein, for the first time, we report novel hierarchical porous chromium niobium oxide (Cr 0.5 Nb 24.5 O 62 ) microspheres prepared by a facile one-step solvothermal method. The as-prepared Cr 0.5 Nb 24.5 O 62 microspheres present 3D hierarchical porous structure consisting of cross-linked nanoparticles, high electronic conductivity and large specific surface area. Accordingly, the Cr 0.5 Nb 24.5 O 62 microspheres show noticeable lithium ion storage performance with superior high-rate capability (199 mAh g −1 at 20C) and good cycling stability with a capacity retention of 95% over 1000 cycles, much better than the bulk Cr 0.5 Nb 24.5 O 62 and TiNb 24 O 62 counterparts. Our work demonstrates a new high-rate electrode material for high-power energy storage.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
无机化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2022
·
IF 9.794
Yuhong Ma,Yu Jiao,Yichao Yan,Wei Chen,Yaoyao Li,Mingjie Zhou,Dongjiang Chen,Jun Zhu
Solid polymer electrolytes drastically enhance the operational safety of Li metal battery by eliminating the flammable liquid electrolyte, but still suffer from low ionic conductivity and inferior thermostability. Herein, we tack this issue by strengthening the polyvinylidene fluoride matrix with lithiophilic polyimide . The actively conjugated carbonyl groups in polyimide polymer backbone with Li + -conductivity feature accelerate the ion conduction, accordingly improving the ionic conductivity up to 4.1 × 10 −4 S cm −1 . With the polyimide solid electrolyte , lithium symmetrical battery shows a stable operation without obvious dendrite growth over 300 h at 0.17 mA cm −2 , effectively uniformizing the Li + deposition at the electrolyte/anode interface. The LiFePO 4 cell based on the polyimide electrolyte delivers a high discharge capacity of 126 mAh g −1 at 25 °C with a capacity retention of 86% after 500 cycles at 0.15 mA cm −2 . In addition, polyimide chain with high thermostability owns affinity to polyvinylidene fluoride with an adsorption energy of 0.1 eV, giving rise to 35% enhancement in mechanical strength and 68% reduction in thermal shrinkage at 300 °C as compared with pure polyvinylidene fluoride electrolyte. This design allows a promising route for enhancing the safety operation of polymer electrolyte and promoting ionic transfer by reconstructing the polymer architecture .
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
电池技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Zewei Chen,Weigang Wang,Jianguo Duan,Feipeng Qian,Yuanpeng Cao,Jingjing He,Ding Wang,Peng Dong,Yingjie Zhang
Among various lithium-ion batteries cathode materials , olivine-type phosphate LiMnPO 4 has the advantages of high working voltage, superior theoretical energy density and high stability, however, its electronic and ionic insulation limit its application. In this work, LiMn 0.90 Fe 0.10 PO 4 /C (LMFP@C) nano composites are prepared via a mechanochemical activation assisted carbothermal reduction method, and the consequence of carbon coating amount on the electrochemical performance of the materials is discussed in detail. The results of physical and chemical properties analysis show that the mechanical liquid activation process can effectively reduce the particle size of the precursor to nanometer scale and make the raw material mixed evenly. The high crystallinity , particle nanometrization and uniform carbon coating enable LMFP@C composites with excellent electrochemical performance even when a small amount of carbon coating is introduced. Under an optimizing coated carbon amount of 2.5 wt%, the material showed ∼4.0 V and ∼3.6 V voltage platforms at 0.1, 0.2, 0.5, 1, and 2C, and released discharge specific capacities of ∼155 mAh·g −1 and ∼140 mAh·g −1 at 0.1 and 1C, respectively. It also shows optimal cycling stability with a capacity retention rate ∼100% after 100 cycles at 2C.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
无机非金属材料
✓ 已验证
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2017
·
IF 4.075
Xing Zhou,Changqing Fang,Xinyu He,Yuzhen Wang,Jie Yang,Leipeng Yang,Jingbo Hu,Yan Li
In thermoplastic polyurethane elastomer (PUE) technology, the necessity for revealing the interactions between clays and polyurethane chains is improving recently. In this paper, three different natural clays (NC) were firstly employed to prepare NC/PUE composites to explore the relation between fillers and PUE chains. We found that the natural clays were formed from sand to fertile soil, and then corroded deeply to CaCO 3 (rock) by surroundings, including water, wind and temperature and so on. Then, the neat PUE and NC/PUE composites were characterized by SEM, TEM , XRD , SAXS , FTIR and DSC to investigate the function of natural clays in polyurethane chains. We found that the different clays particles interacted with PUE chains in different ways. The lamellae and stacks of rock aggregated mainly in PUE matrix and interact with the hard/soft domains, while that of sand and soil aggregates mainly on the surface of PUE matrix.
研究领域:
高分子材料科学
·
复合材料学
·
材料物理与化学
·
界面科学
·
热分析
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2014
·Vol. 43
·期 16
·6132-6138
·
IF 4.097
Wanyuan Li,Rong-Jun Xie,Tianliang Zhou,Lihong Liu,Yuejin Zhu
The promising green oxynitride phosphor, Ba3Si6O12N2:Eu2+, was synthesized at 1350 °C for 5 hours under a reducing N2/H2 (5%) atmosphere by using the solid-state reaction method. The phase purity was investigated by varying the nominal compositions, and the pure phase was achieved by carefully controlling the Si/Ba and O/Ba ratios. The phosphor displayed a broad excitation band spanning from the ultraviolet (UV) to the blue spectral region, and showed a single symmetrical emission band peaking at 525 nm with a full width at half maximum (FWHM) of ∼68 nm. The as-prepared green phosphor exhibited a small thermal quenching, which remained 90% of the initial emission intensity when measured at 200 °C. The internal and external quantum efficiencies measured under 450 nm excitation were 68 and 38%, respectively. Color temperature-tunable white LEDs with a high color rendering index of Ra = 88–94 were attained by combining the prepared green phosphor and a red phosphor Sr2Si5N8:Eu2+ with a blue LED chip.
研究领域:
材料科学
·
无机化学
·
发光材料
·
半导体照明
·
光电工程
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 19
·6569-6577
·
IF 4
Shihao Wu,Heng Liang,Yan Li,Wanfang Zou,Zhijian Liao,Wei Wang,Xinyu Ye
The Cr3+-doped near-infrared (NIR) phosphors have been extensively investigated owing to their promising applications in biomedicine, food safety detection, and night vision surveillance. However, achieving broadband (FWHM > 160 nm) NIR emission is still challenging. In this paper, novel Y2Mg2Ga2−xSi2O12:xCr3+ (YMGS:xCr3+, x = 0.005–0.08) phosphors were prepared by a high-temperature solid-state reaction. The crystal structure, photoluminescence properties of the phosphor, and the device performance of a pc-LED were researched in detail. When excited at 440 nm, the YMGS:0.04Cr3+ phosphor exhibited broadband emission in the range of 650–1000 nm, peaking at 790 nm with a full width at half-maximum (FWHM) of up to 180 nm. The wide FWHM of YMGS:Cr3+ is conducive to its extensive application in NIR spectroscopic technology. In addition, the YMGS:0.04Cr3+ phosphor could maintain 70% of the initial emission intensity at 373 K. By combining the commercial blue chip with the YMGS:0.04Cr3+ phosphor, the resulting NIR pc-LED demonstrated a near-infrared output power of 14 mW with a photoelectric conversion efficiency of 5% at a drive current of 100 mA. This work provides a broadband emission NIR phosphor option for NIR pc-LED devices.
研究领域:
材料科学
·
光学工程
·
生物医学工程
·
光电子学
·
固体化学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 24
·8414-8424
·
IF 4
Tao Tan,Ran Pang,Shangwei Wang,Haiyan Wu,Jiutian Wang,Su Zhang,Chengyu Li,Hongjie Zhang
Cr3+-activated phosphors with high quantum efficiency show excellent promise in the field of near-infrared (NIR) phosphor converted light-emitting diodes (pc-LEDs). Here, we design an annealing program for Cr3+-doped phosphors containing variable valence elements that cannot be prepared in a reducing atmosphere to enhance their luminescence efficiency and thermal stability. A novel phosphor, Li2Mg3SnO6:Cr3+, developed by this annealing design, containing variable valence element Sn, exhibits higher quantum efficiency and better thermal stability than the one prepared by the conventional solid-state reaction. The Li2Mg3SnO6:0.03Cr3+ sample exhibits broadband NIR emission with a full width at half-maximum (FWHM) of 201 nm. After annealing, the internal quantum efficiency (IQE) and external quantum efficiency (EQE) of the Li2Mg3SnO6:0.03Cr3+ sample are enhanced from 48.5% to 84.7% and from 22.7% to 32.6%, respectively, and the thermal quenching temperature at which the luminescence intensity of the phosphor reduces to half of its initial value is promoted from ∼400 K to ∼425 K. The luminescence intensity of the optimized Li2Mg3SnO6:0.03Cr3+ sample at 425 K (∼152 °C) remains 49.2% of its initial intensity at 300 K. A NIR pc-LED is fabricated by combining the optimized Li2Mg3SnO6:0.03Cr3+ sample with a blue LED (455 nm blue chip), and the NIR radiant fluxes of 3.676 mW (at 10 mA) and 29.21 mW (at 100 mA), as well as a maximum NIR photoelectric efficiency of 14.2%, are obtained. The results show that this novel phosphor has great application potential in NIR pc-LEDs, and the annealing design exhibits huge potential for improving the optical properties of Cr3+-activated phosphors.
研究领域:
材料科学
·
光学工程
·
固体物理
·
光电子学
·
无机化学
✓ 已验证
DOI
高影响因子
Journal of Macromolecular Science Part A-Pure and Applied Chemistry
·
2014
·
IF 0.74
Guolun Xiahou,Weiqu Liu,Zhenlong Yan,Kui Su,Honglei Wang
Long side chain polyurethane oligomers were synthesized from tolylene diisocyanate (TDI), polyether triol (N330) and monohydroxy terminated polydimethylsiloxane (M-PDMS, ), and the structures were characterized by FT-IR spectrum. Subsequently, they were mixed with polyurethane oligomers synthesized from TDI and polyether triol (N220) to obtain M-PDMS graft modified polyurethanes (M-PDMS-PUs). Dihydroxy terminated polydimethylsiloxane modified polyurethanes (D-PDMS-PUs) were also prepared for the study in contrasts with M-PDMS-PUs. The influence of concentration and length of PDMS on the surface, thermal and mechanical properties was investigated by contact angle measurement, thermo-gravimetric analysis (TGA), different scanning calorimeter (DSC) and mechanical testing. Water contact angles showed the M-PDMS-PUs had higher contact angles than that of D-PDMS-PUs. Added with low amount of PDMS (2.6 wt%), the water contact angle of M-PDMS-PU was 95.5°C while that of D-PDMS-PU was 88.0o. TGA data showed that M-PDMS-PU (Tmax = 368.0°C) had better thermal stability than that of D-PDMS-PU (Tmax = 362.2°C) at low PDMS concentration (2.6 wt%). DSC data revealed that the incorporation of PDMS into PU resulted in a decrease in Tg values and the Tg values of D-PDMS-PUs decreased more drastically than those of M-PDMS-PUs. Mechanical testing indicated that the tensile strength, elongation at break and Shore A hardness of the PDMS modified polyurethanes decreased with the increase of the PDMS content. The morphologies of the fracture surfaces of the copolymers showed that microphase separation between PU and PDMS was formed in both types of PDMS modified polyurethanes and the size of the polysilicone phase became larger with increasing the PDMS content.
研究领域:
高分子化学
·
材料科学
·
表面科学
·
热分析
·
力学性能测试
✓ 已验证
DOI
高影响因子
ACS Biomaterials Science & Engineering
·
2018
·
IF 4.432
Yan Ma,Xianwen Wang,Huajian Chen,Zhaohua Miao,Gang He,Junhong Zhou,Zhengbao Zha
To surmount the challenges of limited drug penetration and therapeutic resistance in solid tumors, stimuli-responsive nanocarrier-based drug delivery systems (DDSs) with relatively small sizes are inherently favorable for combined treatment of cancerous cells. In this work, poly(acrylic acid) (PAA) functionalized Co0.85Se nanoparticles (PAA-Co0.85Se NPs) were synthesized through an ambient aqueous precipitating approach for synergistic photothermal-chemo treatment of cancer. The obtained PAA-Co0.85Se NPs possess ultrasmall size (8.2 ± 2.6 nm), considerable near-infrared (NIR) light absorption, high photothermal transforming efficiency (45.2%) and low cytotoxicity, all of which are beneficial for localized photothermal ablation of cancer cells. Doxorubicin hydrochloride (DOX·HCl) was then successfully loaded on PAA-Co0.85Se NPs with a loading capacity up to 8.3% to form PAA-Co0.85Se-DOX composites, which exhibited an exciting acidic pH-responsive drug release property due to the protonation of amino groups in DOX and carboxyl groups in PAA molecules. As expected, when HeLa cells were treated with PAA-Co0.85Se-DOX NPs as well as NIR laser irradiation, a significant synergistic cell-killing effect was observed, greatly improving the treatment efficiency. Thus, this work presents novel insight into the design of ultrasmall stimuli-responsive nanocarrier-based DDSs for synergistic photothermal-chemo treatment of cancer cells.
研究领域:
肿瘤学
·
纳米医学
·
生物材料
·
药物递送
·
光热治疗
·
化学生物学
·
转化医学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2012
·Vol. 2
·期 27
·10330-10336
·
IF 0
Jungang Hou,Chao Yang,Zheng Wang,Shuqiang Jiao,Hongmin Zhu
Large-scale hydrogen production through water splitting using photocatalysts with solar energy can potentially produce clean fuel from renewable resources. In this work, photocatalytic hydrogen evolution with a high efficiency was achieved using CdS nanocrystal decorated CdLa2S4 microspheres (CdS/CdLa2S4) successfully prepared by a two-step hydrothermal process. The obtained CdS/CdLa2S4 composite was characterized by X-ray diffraction (XRD), electron microscopy (EM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance absorption spectroscopy (DRS), and photoluminescence spectroscopy (PL). XRD demonstrated that highly crystalline hexagonal CdS was obtained in CdS/CdLa2S4. EM results revealed that CdLa2S4 microspheres assembled from a large number of nanoprisms, were intimately enwrapped by the surrounding CdS nanocrystals with a particle size below 20 nm. This unique architecture resulted in the appropriate dispersion of CdS nanocrystals and intimate multipoint contacts between the CdS nanocrystals and CdLa2S4, which led to significant enhancement of charge separation in CdS/CdLa2S4. Especially, the CdLa2S4 microspheres decorated with 3 wt% CdS nanocrystals containing 0.4 wt% of Pt showed a high rate of H2-production at 2.25 mmol h−1 with an apparent quantum efficiency of 54% under 420 nm monochromatic light. The rate of hydrogen evolution from water splitting was 9 times faster in comparison with the rate observed on pure CdLa2S4, which is ascribed to the presence of CdS nanocrystals that alter the energy levels of the conduction and valence bands in the coupled semiconductor system.
研究领域:
材料科学
·
光催化
·
能源化学
·
纳米材料
·
半导体物理
·
可再生能源
·
催化化学
✓ 已验证
DOI
MICROPOROUS AND MESOPOROUS MATERIALS
·
2015
·
IF 3.453
Xiaoyun Chen,Dong-Hau Kuo,Dongfang Lu,Yongxuan Hou,Yen-Rong Kuo
Mesoporous TiO 2 was synthesized by a hydrolysis precipitation method with the utilization of the biological renewable resource of lignin as template and TiCl 4 as reactant. The photocatalytic activity of TiO 2 was investigated by the degradation of phenol under UV light irradiation. The microstructure, crystallinity , powder characteristic, and chemical bonding of the catalyst were analyzed. The 500 °C-calcined TiO 2 had average crystallite size of about 11.1 nm and a mesoporous structure with specific area of 165.8 m 2 /g and pore volume of 0.312 cm 3 /g. The results showed that TiO 2 synthesized with lignin template exhibited high photocatalytic activity, which can be attributed to the electronegativity and the network skeleton of lignin to uniformly distribute the TiO 2 precursor for forming TiO 2 mesoporous particles. The mechanism for the improved photodegradation of the lignin-assisted TiO 2 was proposed.
研究领域:
材料科学
·
环境化学
·
纳米技术
·
光催化
·
绿色化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）