ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Siwei Zhao,Ying Chen,Zhiyang Zhao,Longfei Jiang,Chi Zhang,Jianshou Kong,Xufei Zhu
Anodic TiO 2 nanotubes have been intensively studied for the application in supercapacitors , but the formation of nanograss is often avoided for the belief that it may retard capacitive performance. We fabricate TiO 2 nanotubes topped with nanograss by H 3 PO 4 solution soaking and hydrogenation doping, which in fact increases the capacitance of nanotubes in a fast and convenient way. The new structure exhibits an enhanced areal capacitance by up to 67.7% and by up to 23.5% after 2000 times of cycling. The capacitance generally increases with the nanotube length and reaches the maximum with an optimal nanograss length. The electric charge during hydrogenation doping is determined to quantify the general doping effect. Compared with ordinary nanotubes, nanograss has larger contact area with electrolyte during doping. Therefore, the grass-topped structure yields more electric charge and Ti 3+ during doping, which attributes to the improved capacitance.
研究领域:
材料科学
·
纳米技术
·
电化学
·
能源存储
·
表面工程
✓ 已验证
DOI
高影响因子
Small
·
2023
·Vol. 19
·期 41
·2302685
·
IF 13.3
Hancheng Ma,Xiang Huang,Luyu Li,Wei Peng,Sheng Lin,Yao Ding,Liqiang Mai
PtTe 2 , a member of the noble metal dichalcogenides (NMDs), has aroused great interest in exploring its behavior in the hydrogen evolution reaction (HER) due to the unique type-II topological semimetallic nature. In this work, a simple template-free hydrothermal method to obtain the phosphorus-doped (P-doped) PtTe 2 nanocages with abundant amorphous and crystalline interface (A/C-P-PtTe 2 ) is developed. Revealed by density functional theory calculations, the atomic Te vacancies can spontaneously form on the basal planes of PtTe 2 by the P doping, which results in the unsaturated Pt atoms exposed as the active sites in the amorphous layer for HER. Owing to the defective structure, the A/C-P-PtTe 2 catalysts have the fast Tafel step determined kinetics in HER, which contributes to an ultralow overpotential ( η = 28 mV at 10 mA cm −2 ) and a small Tafel slope of 37 mV dec −1 . More importantly, benefiting from the inner stable crystalline P-PtTe 2 nanosheets, limited decay of the performance is observed after chronopotentiometry test. This work reveals the important role of the inherent relationship between structure and activity in PtTe 2 for HER, which may bring another enlightenment for the design of efficient catalysts based on NMDs in the near future.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源材料
·
计算材料学
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2014
·
IF 2.633
Guang-Rui Xu,Miao-Jun Xu,Bin Li
The cyclotriphosphazene-based epoxy resin hexa-[4-(glycidyloxycarbonyl) phenoxy]cyclotriphosphazene defined as CTP-EP was successfully synthesized from hexachlorocyclotriphosphazene, p -hydroxybenzaldehyde and epichlorohydrin. Its chemical structure was characterized by Fourier transform infrared (FTIR) spectroscopy, 1 H NMR, 13 C NMR and 31 P NMR spectroscopy . The prepared compound was cured with diamino diphenyl methane (DDM), diamino diphenyl sulfone (DDS) and m -phenylenediamine (mPDA), respectively. The flame retardant properties, thermal degradation behavior and flame retardant mechanism of the cured CTP-EP were investigated. The LOI values of all cured CTP-EP samples increased from 19.9% for cured diglycidyl ether of bisphenol-A (DGEBA) to above 30% and successfully passed UL-94 V-0 rating, which demonstrated that the prepared CTP-EP thermoset exhibited excellent flame retardancy. The dynamic mechanical thermal analysis (DMA) test demonstrated that the glass transition temperature ( Tg ) enhanced from 155 °C for the cured DGEBA to 167 °C for CTP-EP thermoset . The results of thermogravimetric analysis/infrared spectrometry (TG-IR) tests suggested that the phosphazene group and high aromatic content in CTP-EP thermoset stimulated the dehydration of the matrix at earlier degradation process and the formation of char layer, which retarded the release of pyrolysis gas and enhanced the thermal stability of the cured CTP-EP at high temperature. The cone calorimeter tests (cone) test revealed that heat release rate (HRR), total heat release (THR), smoke production rate (SPR) and total heat production (TSP) of the cured CTP-EP decreased significantly compared with the cured DGEBA. The scanning electron microscopy (SEM) results showed that the phosphazene groups in CTP-EP obviously stimulated the formation of the intumescent, compact and stable char layer, which enhanced the flame retardancy of the matrix during combustion. Consequently, the underlying materials were protected from further degradation and combustion during a fire and result in the efficient flame retardancy of CTP-EP thermoset.
研究领域:
高分子化学
·
材料科学
·
热分析
·
阻燃材料
·
聚合物化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Bin Xiao,Wen-hai Zhang,Peng-bo Wang,Lin-bo Tang,Chang-sheng An,Zhen-jiang He,Hui Tong,Jun-chao Zheng,Bo Wang
Phosphate-based polyanion-structured materials have attracted considerable attention as anode materials in lithium-/sodium-ion batteries due to their stable crystal structure, affordability, and environmental friendliness. V 2 (PO 4 )O was encapsulated into crumpled nitrogen-doped graphene (VPO@N-G) through a facile spray-drying method in which VPO particles were completely encapsulated by N-doped graphene. For the first time, VPO@N-G was explored as an anode material for sodium-ion batteries. The Na + storage behavior of VPO@N-G was systematically investigated at the voltage range of 0.01–3.0 V (versus Na/Na + ). Results indicated that the VPO@N-G anode can deliver a highly reversible discharge capacity of 539 mAh g −1 at 0.05 A g −1 and achieve a highly reversible discharge capacity of 235.9 mAh g −1 even at a high current density of 10 A g −1 . Thus, VPO@N-G can be applied as a high-rate anode material for sodium-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米复合材料
·
无机功能材料
✓ 已验证
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·Vol. 11
·期 8
·7066-7075
·
IF 1.5
Jiheng Ding,Hongran Zhao,Lin Gu,Shengpei Su,Haibin Yu
This paper reports the synthesis of waterborne epoxy phosphate emulsion (WEP) through the reaction between epoxy resin E44 and phosphoric acid and ammonia neutralization. Synthesized WEP was characterized by FTIR for the confirmation of reaction between epoxy groups and phosphoric acid and SEM for morphology. WEP acted as a modifier in two-component epoxy anticorrosion coating on rusty steel substrate. The anticorrosion properties of the coating on rusty steel were investigated by electrochemical impedance spectroscopy (EIS) and Tafel polarization curve. Tafel polarization curve revealed that waterborne epoxy coating containing WEP had better protection ability which is clearly reflected by the protection efficiency (96.6%). EIS study also showed the higher impedance value for WEP containing coating as compared to pure waterborne epoxy coating.
研究领域:
材料科学
·
腐蚀与防护
·
高分子化学
·
表面工程
·
电化学
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2019
·
IF 3.42
Youtong Wu,Shaoguo Wen,Kaiming Chen,Jihu Wang,Guangyu Wang,Kai Sun
Compared with solvent-based resins, waterborne resins still have defects such as insufficient anti-corrosion efficiency. In this paper, the sulfonated graphene/zinc phosphate composites were prepared as an anti-corrosion filler and doped into waterborne polyurethane resin. The morphology of composites is different from pure zinc phosphate. The optimal corrosion resistance can be obtained by adding 0.5 wt% sulfonated graphene/zinc phosphate fillers characterized by Potentiodynamic polarization curves and EIS analysis The corrosion current density ( i corr ) was 0.4252 μA/cm 2 and the charged transfer resistance (R ct ) was up to 10.937 × 10 3 Ω cm 2 , which show a good potential as anti-corrosive fillers in waterborne coatings system.
研究领域:
材料科学
·
高分子化学
·
表面工程
·
腐蚀与防护
·
涂层技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 86
·45930-45938
·
IF 3.708
Mengmeng Zhang,Hongxia Yan,Xiaowei Yang,Chao Liu
In this paper, graphene oxide (GO) was functionalized with a hyperbranched cyclotriphosphazene polymer, which was synthesized by the repeated reactions of hexachlorotriphosphazene with hexamethylenediamine. Subsequently, the resultant functionalized GO was incorporated into dicyclopentadiene bisphenol dicyanate ester (DCPDCE) to prepare composites. Fourier-transform infrared spectra, X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron spectroscopy were employed to examine the surface functionalization of GO. The effects of functionalized GO on the curing reactivity, mechanical, dielectric, thermal and water resistent properties of DCPDCE resin were investigated systematically. Results show that the addition of modified GO can facilitate the curing reaction of DCPDCE. Meanwhile, the appropriate content of modified GO can enhance the mechanical properties including impact and flexural strengths of DCPDCE resin. When modified GO content is 0.6 wt%, the corresponding composite exhibits slightly higher dielectric constant but lower dielectric loss than pure DCPDCE resin over the testing frequency from 10 to 60 MHz. In addition, the thermal stability and moisture resistance of modified GO/DCPDCE nanocomposties are also superior to that of pure DCPDCE resin.
研究领域:
高分子化学
·
复合材料科学
·
材料物理与化学
·
纳米材料
·
绝缘材料
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Shigen Bai,Yong Tang,Gong Chen,Yaopeng Wu,Yifu Liang,Shu Yang,Huilong Liu,Yingxi Xie
Supercapacitors (SCs) have garnered increasing attention as an alternative energy storage device but the relatively low potential window and energy density impede their application prospect. Herein, we propose a novel three-dimensional (3D) packaging method for the first time, utilizing high flexible phosphor-copper sheets (PCSs) sprayed with polytetrafluoroethylene (PTFE) and covered with polyimide (PI) films on their both sides as the serial medium followed by CO 2 laser irradiation to fabricate all-solid-state flexible high voltage supercapacitors (HVSCs). This method achieves double voltage output in the limited PI membrane compared with common 2D encapsulation. As a result, as-obtained HVSCs deliver not only an enhanced mechanical tensile strength up to 18.23 MPa but also the outstanding electrochemical performances, including ultrahigh working voltage window (10 V), high energy density (37.68 μWh/cm 2 ) and power density (3.38 mW/cm 2 ). Owing to the excellent flexibility, the HVSCs can be arbitrarily bent or twisted without obvious attenuation on capacitive property. After 10000 cycles, the capacitance retention of HVSCs still maintains to be 90.2%. This novel 3D packaging strategy may pave the way for developing high-performing SCs with wide operating voltage and high energy density for flexible displays, wearable equipment and integrated electrical devices.
研究领域:
材料科学
·
纳米技术
·
能源存储
·
柔性电子
·
电化学
·
高分子材料
·
先进制造
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 46
·期 13
·21560-21568
·
IF 3.83
Mingcai Li,Xuejie Zhang,Yinjian Zheng,Yaliang Xu,Haoran Zhang,Yingliang Liu,Bingfu Lei
The discovery of light converter excited by near-ultraviolet (UV) superior broadband blue-emitting lighting source is a main challenge in plant growth LEDs. In this study, SrLu 2 O 4 :Ce 3+ , Li + , F − blue phosphor has been synthesized via a solid-state reaction. Benefitting from doping of F − ions, SrLu 2 O 4 :Ce 3+ , Li + , F − phosphor (λ ex = 405 nm, λ em = 460 nm) shows a strong broadband (FWHM = 90 nm) blue-emitting with lower critical concentration of Ce 3+ ions and an increasing 6.9% thermal quenching performance (92.1% @ 423 K of the peak intensity at room temperature). Moreover, a blue light converter composed of SrLu 2 O 4 :Ce 3+ , Li + , F − phosphor and glass matrix is obtained based on phosphor-in-glass (PiG) technology, exhibiting excellent thermal stability and outstanding moisture resistance . A red light converter with commercial red phosphor is obtained by the same method. Furthermore, by combining of two light converters with near-UV chip, a proof-of-concept plant growth high power LED is achieved and applied in indoor Italian lettuce growing in comparison with commercial plant lamps.
研究领域:
材料科学
·
光学工程
·
农业光电子学
·
固体发光
·
无机非金属材料
✓ 已验证
DOI
高影响因子
Advanced Electronic Materials
·
2023
·Vol. 9
·期 11
·2300392
·
IF 6.2
Guangliang Li,Lingxian Kong,Qi Su,Xianhua Tan,Xuning Zhang,Zhiyong Liu,Tielin Shi,Guanglan Liao,Bo Sun
Few-layer black phosphorus (FL-BP) shows great potential in infrared polarization-sensitive photodetection due to its narrow bandgap and strong in-plane anisotropy. However, FL-BP is easy to be oxidized and degraded, which severely restricts its applications. Herein, a simple and scalable in situ interfacial passivation method based on pentacene film is reported to enhance the ambient stability of FL-BP as well as achieve n-type doping for improved polarization-sensitive photoimaging. High crystal quality FL-BP flakes with intrinsic anisotropy are prepared by electrochemical exfoliation. The morphology and Raman spectra of FL-BP/pentacene exhibit excellent stability 28 days after passivation. In addition, the hole mobility is significantly enhanced and dark current is substantially suppressed due to the interfacial passivation and n-type doping effect. The FL-BP/Pentacene based photodetector shows a broadband response from visible to near-infrared with good stability. The photoresponsivity under 915 nm illumination is calculated as 2.2 mA W −1 with an anisotropy ratio of 1.29. Furthermore, the polarization imaging under the irradiation at zigzag and armchair directions directly reveals the strong infrared polarization-sensitive imaging capability of FL-BP/pentacene. This work also opens up new avenues to enhance the photoresponse and stability of various optoelectronics based on similarly unstable 2D materials.
研究领域:
纳米材料学
·
光电子学
·
二维材料
·
半导体物理
·
红外成像
·
表面科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Hongshi Zhang,Jiyou Zhong,Xiaoli Zhang,Huanxin Yang,Zhongfei Mu,Weiren Zhao
Spectral coverage and saturability within 700–1100 nm of phosphor-converted near infrared light-emitting-diodes (pc-NIR LEDs) are crucial for the practical applications in bioimaging, food quality analysis and night vision fields, while developing ultra-broadband NIR phosphors are still a challenge. Herein, we reported a broadband NIR phosphor LiInP 2 O 7 : Cr 3+ in phosphate system. The emission spectrum of this phosphor covers 700–1200 nm with a full width at half maximum (FWHM) of 165 nm and an emission peak centering at 860 nm under 460 nm excitation. This broadband emission is verified to be derived from 4 T 2 g → 4 A 2 g transition of Cr 3+ in a single crystal site. To further expand the emission spectrum , Cr 3+ →Yb 3+ energy transfer in LiInP 2 O 7 was designed, and an ultra-broadband emission with a FWHM of 225 nm was obtained through appropriate amount of Yb 3+ codoping. The energy transfer efficiency can reach as high as 81% in this material. Furthermore, the energy transfer mechanism, quantum yield , thermal stability and fabrication performance were investigated in detail, demonstrating the ability of achieving ultra-broadband and efficient NIR emission of LiInP 2 O 7 : Cr 3+ , Yb 3+ phosphor material.
研究领域:
光学材料
·
生物医学成像
·
分子探针
·
光电子学
·
无机功能材料
✓ 已验证
DOI
高影响因子
Energy Storage Materials
·
2018
·
IF 0
Tao Yuan,Jiafeng Ruan,Chengxin Peng,Hao Sun,Yuepeng Pang,Junhe Yang,Zi-Feng Ma,Shiyou Zheng
Phosphorus (P) is considered one of the most attractive anodic materials for lithium-ion batteries (LIBs) owing to its high theoretical specific capacity (2596 mAh g −1 ). Nevertheless, it suffers from intrinsic poor conductivity (10 −12 S m −1 ) and large volume expansion (~440%) during the lithiation process, leading to low reaction dynamics and serious capacity decay upon cycling. In this work, red P confined in a three-dimensional (3D) sheared carbon nanotube (SCNT) conductive sponge is prepared, showing high capacity and long cyclability as anodes for LIBs. The resultant 3D P-SCNT composite delivers a stable capacity of 1600 mAh g −1 at a current density of 0.1 A g −1 and a reversible high-rate capacity as high as 782 mAh g −1 at 2 A g −1 even after 3000 cycles, owing to the robust support of the SCNT framework and stable chemical bonds between the evenly distributed red P and SCNT.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
功能材料
✓ 已验证
DOI
危险品化学品经营许可证（带存储）