JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Yingying Lai,Lizhang Lv,Heqing Fu
In this work, Al 2 O 3 @PPy@rGO composites were successfully synthesized by a “coating-coating” route. The structure of Al 2 O 3 @PPy@rGO composites was characterized by XRD , Raman and SEM. The coaxial wire method was used to measure the electromagnetic properties of Al 2 O 3 @PPy@rGO composites, which was carried on the vector network analyzer (VNA, 3672A/B/C-S) over the 2–18 GHz frequency range. Compared with Al 2 O 3 (about 50 nm), the particle size of Al 2 O 3 @PPy composites (about 70 nm) enhanced, which verified the alumina was coated by PPy . In addition, the Al 2 O 3 @PPy composites are tightly attached by the rGO with a diameter of about 30 nm Al 2 O 3 @PPy@rGO composites have excellent thermal stability, and they remain 53 wt% when the temperature is up to 800 °C. When the thickness of Al 2 O 3 @PPy@rGO composites is 3.0 mm, they reach the maximum reflection loss of −39.7 dB at 13.2 GHz with 15 wt% Al 2 O 3 @PPy@rGO-wax. And the broad effective microwave absorption bandwidth of Al 2 O 3 @PPy@rGO composites is 5.5 GHz in 10.5–16.0 GHz. In addition, the electromagnetic wave absorption mechanism of Al 2 O 3 @PPy@rGO composites was analyzed.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Zhimin Li,Guanhui Chen,Shuqi Gou,Xiaofang Deng,Zhongai Hu,Xiaoquan Lu
The quasi-solid-state flexible supercapacitor has been successfully built by freezing-thawing method and in-situ polymerization. The high redox activity nickel-iron layered double hydroxide (NiFe-LDH) provides certain pseudocapacitance, interacts with high conductivity reduced graphene oxide (RGO), and avoids the activity structural collapse and agglomeration. Polyvinyl alcohol (PVA) serves as a flexible framework with uniform cross-linking between the components, facilitated by the presence of abundant hydrogen bonds. Polypyrrole (PPy) is further polymerized in-situ into PVA/RGO/NiFe-LDH to improve its electrochemical performance and flexibility. The PVA/RGO/NiFe-LDH 0.40 /PPy hydrogel electrodes exhibit a high area specific capacitance of 729 mF/cm 2 at 1 mA/cm 2 . The elongation at break of the electrodes is up to 749 %, which reflects excellent tensile properties. The quasi-solid-state flexible supercapacitor has been built using PVA/H 2 SO 4 as the gel electrolyte and PVA/RGO/NiFe-LDH 0.40 /PPy as the electrodes. The device exhibits a high energy density of 15.9 µWh/cm 2 at a power density of 0.19 mW/cm 2 and the capacitance retention of 96.7 % after 10,000 charge-discharge cycles.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Jian Li,Wenbin Luo,JinFeng Ou,Yi Yu,Zhen Zhang,Zisheng Chao,JinCheng Fan,WenJun Yi,Yadong Wang
Aluminum batteries (ABs) are a promising alternative to lithium-ion batteries (LIBs) in the future. The development of aluminum batteries (ABs) is closely related to their cathode material. In this paper, we successfully designed and prepared a nanorod structure Sb 2 Se 3 @PPy as cathode material for ABs. It exhibits a high reversible capacity of 302 mAh/g at 0.2 A/g, and the capacity is maintained at about 210 mAh/g after 50 cycles. In addition, the electrochemical reaction mechanism and kinetic process of Sb 2 Se 3 @PPy were studied. The results showed that the PPy coating layer reduced the volume change of Sb 2 Se 3 , prevented irreversible deformation, enhanced the structural stability and electronic conductivity.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2024
·
IF 5.5
Wenyu Bai,Chenglong Li,Feng Pan,Yu Luo,Tongtong Gao,Di Yu,Xiaorui Wang,Han Sun,Shuang Wang
The choice of electrode materials affects the electrochemical performance of supercapacitors, and the selection of suitable electrode materials is necessary to enable the industrialization of supercapacitors. The conductive polymer polypyrrole is well known to researchers for its excellent electrochemical properties, but pure polypyrrole does not fulfill its advantages. The disadvantage is that the microstructure of the polypyrrole molecules, which is favorable for energy storage when supercapacitors are being charged and discharged, is greatly damaged by the contraction/expansion of the polypyrrole molecular chains, which directly affects the electrochemical performance of the supercapacitors assembled subsequently. So firstly, we modified PPy by using the functional group nature of 3-amino-4-methylene-phenylboronic acid (g-PPy) to give it more active sites. Secondly, MXene acts as the backbone of g-PPy, which limits the expansion and contraction of the volume supercapacitors and improves cycle stability when charging and discharging. In contrast, the compounded MXene/g-PPy has good specific capacitance and stability after several thousand cycles, due to the nature of the functional group of 3-amino-4-methylenebenzeneboronic acid, a large number of g-PPy active sites, the good hydrophilicity of the MXene surface for interaction with sodium dodecylbenzene sulfonate and the hydrogen bonding between MXene and g-PPy, Even after 10000 charge/discharge cycles, its stability is significantly improved with a capacity retention rate of 98.6 %. In addition, the corresponding symmetrical supercapacitors were tested to exhibit significant cycling stability at a low temperature. This study, therefore, provides a method for the preparation of MXene based electrodes with high cycling stability by modifying the electrodes.
研究领域:
材料科学
·
电化学
·
能量存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Tiansheng Liu,Na Liu,Shangru Zhai,Shengshuai Gao,Zuoyi Xiao,Qingda An,Dongjiang Yang
Well-ordered core/shell/shell-like Fe 3 O 4 @SiO 2 @PPy microspheres with prominent electromagnetic microwave absorption performance were successfully obtained by microemulsion polymerization method. The morphology, crystal form, functional group, magnetism and microwave absorption properties were investigated. The tailored shell thickness can be tuned from 20 to 60 nm (including SiO 2 layer) via changing the molar ratio of Fe 3 O 4 @SiO 2 to Pyrrole. The absorption peak positions gradually move to low frequency with increment of coating thicknesses. The minimum RL reached −40.9 dB at 6 GHz with the coating thickness of 5 mm. The effective absorption bandwidth could reach 6.88 GHz from 11.12 to 18 GHz, completely covering the whole K (12–18 GHz) band. Meanwhile, it showed excellent wave absorption in 4.4–18 GHz with different coating thickness. The perfect electromagnetic wave absorption properties could be attributed to the dielectric loss from the special core/shell/shell microstructure and natural resonance from the Fe 3 O 4 microspheres. These newly prepared Fe 3 O 4 @SiO 2 @PPy microspheres might be considered as prospective nominees for highly efficient microwave absorption materials with tailored nanostructures .
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
SYNTHETIC METALS
·
2021
·
IF 3.266
Yuhua Dong,Kexin Wu,Yuanyuan Yin,Chundong Geng,Qiong Zhou
PPy@PDA nanoparticles , prepared by varying ratios of PPy and dopamine hydrochloride, could be used as near infrared (NIR)-absorbing photothermal agents given that the UV–vis–NIR light absorption spectra showed a broad absorption band at 800–900 nm. A NIR-induced shape memory-assisted self-healing epoxy resin coating was obtained, and its shape memory effect was investigated by 808 nm NIR irradiation. Results indicated that the addition of PPy@PDA nanoparticles improved the shape recovery behavior of the composite. The self-healing property of the coatings was investigated by electrochemical test. Results of linear sweep voltammetry (LSV) and electrochemical impedance spectra (EIS) verified that the coating with 5 wt% PPy@PDA nanoparticles had a much better light-induced shape memory effect, self-healing performance, and protective capability than those of other contents of PPy@PDA nanoparticles. Moreover, the shape memory effect of the coating should be affected by the corrosion product of the metallic substrate.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Yuxin Bi,Mingliang Ma,Zijian Liao,Zhouyu Tong,Yan Chen,Rongzhen Wang,Yong Ma,Guanglei Wu
The conductive networks for electron hopping and migration constructed by one-dimensional (1D) composite absorbers are highly desirable to improve the electromagnetic (EM) wave attenuation capacity. Herein, the Ni@Co/C@polypyrrole (PPy) composites integrating the advantages of component and microstructure were fabricated. The addition of Co/C and PPy effectively optimized the impedance matching and improved the EM attenuation. Under the comprehensive impacts of multiple reflections/scattering, conduction loss and interface polarization, the Ni@Co/C@PPy composites showed superior EM wave absorption with the reflection loss (RL) value of −48.76 dB and the effective absorption bandwidth (EAB) of 5.10 GHz at a corresponding thickness of 2.0 mm. The largest EAB could reach 5.54 GHz (7.24–12.78 GHz) at the thickness of 2.2 mm. This work provides a great reference for fabricating 1D novel EM wave absorption materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Storage
·
2023
·
IF 9.4
Lizhong He,Zengpeng Guo,Najeeb ur Rehman Lashari,Gexi Wang,Mengbin Li
To cater to the mushrooming advanced energy storage devices need, designing and preparing novel electrode materials with excellent electrochemical properties (including high capacitance and prominent cycling stability) are urgent but challenging. Here, we successfully synthesized 3D hierarchical NiCo 2 O 4 @Co 3 S 4 @MnS@PPy (NC@CS@MS@PPy) core-sheath nanowire arrays grown on highly conductive carbon cloth using a multistage process. Owing to a lot of synergy between the multiple components in the as-obtained composite, the prepared electrode material indicates an excellent specific capacitance of 2.67 F cm −2 at 1 mA cm −2 or 2557.58 F g −1 at 1 A g −1 and high cycling stability (83.64 % capacitance retention after 20,000 cycles even at a high current density of 20 mA cm −2 ). When coupled with the activated carbon (AC, as a negative electrode), the assembled all-solid-state NC@CS@MS@PPy//AC asymmetric supercapacitor (ASC) device showed outstanding electrochemical properties with a high area specific capacitance 684.38 mF cm −2 at 3 mA cm −2 and better long-term cycling stability (96.76 % retention of the initial capacitance after 20,000 cycles). More importantly, by taking advantaging of the multiple compositional merits and structural features of the positive electrode , the device delivered the highest energy density of 81.1 Wh kg −1 at 800 W kg −1 and retained 26.2 Wh kg −1 at the highest power density of 16 KW kg −1 . Furthermore, two ASCs connected in series powered 20 red light-emitting diodes (LEDs) for >10 min. This work manifests that the prepared hierarchical NC@CS@MS@PPy core-sheath nanowire arrays have impressive potential as high-performance electrodes for supercapacitor.
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
SENSORS
·
2021
·Vol. 21
·期 9
·3069
·
IF 3.576
Qiannan You,Zhongyang Guo,Rui Zhang,Zhimin Chang,Mingfeng Ge,Qian Mei,Wen-Fei Dong
Two-dimensional (2D) MXenes have shown a great potential for chemical sensing due to their electric properties. In this work, a Ti3C2Tx/polypyrrole (MXene/PPy) nanocomposite has been synthesized and immobilized into a glassy carbon electrode to enable the simultaneous recognition of dopamine (DA) and uric acid (UA) under the interference of ascorbic acid (AA). The multilayer Ti3C2TxMXene was prepared via the aqueous acid etching method and delaminated to a single layer nanosheet, benefiting the in-situ growth of PPy nanowires. The controllable preparation strategy and the compounding of PPy material remain great challenges for further practical application. A facile chemical oxidation method was proposed to regulate magnitude and density during the forming process of PPy nanowire, which promotes the conductivity and the electrochemical active site of this as-prepared nanomaterial. The MXene/PPy nanocomposite-modified electrode exhibited the selective determination of DA and UA in the presence of a high concentration of AA, as well as a wide linear range (DA: 12.5–125 μM, UA: 50–500 μM) and a low detection limit (DA: 0.37 μM, UA: 0.15 μM). More importantly, the simultaneous sensing for the co-existence of DA and UA was successfully achieved via the as-prepared sensor.Keywords:simultaneous recognition;dopamine;uric acid;MXene/PPy nanocomposite
研究领域:
生物化学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2021
·
IF 4.464
Jia Wang,Zunli Mo,Nijuan Liu,Ruibin Guo,Chao Shuai,Fang Chen,Yongxin Du,Jingjing Liu,Guigui Liu,Qibing Dong,Qinqin Gao,Ying Chen,Wentong Liu
A simple and effective chiral selector is reported baseing on Cu 2+ and β-cyclodextrin (Cu-β-CD), which can be self-assembled with sodium alginate (SA) as a chiral sensor (SA-CD). The composite of C 3 N 4 and Ppy (C 3 N 4 /Ppy) was used as an electroactive material for the enantiomeric selection of tryptophan (Trp) by differential pulse voltammetry (DPV). The sensor was constructed by combining the advantages of polysaccharide SA-CD and C 3 N 4 /Ppy. SA-CD as a chiral selector can provide a large number of chiral sites, and C 3 N 4 /Ppy as a substrate material can improve the electrochemical signal. The results showed that the electrochemical signal of C 3 N 4 /Ppy/SA-CD modified GCE to l -Trp was higher than that to d -Trp. This was due to the low affinity of C 3 N 4 /Ppy/SA-CD modified GCE to l -Trp, which made it easier for l -Trp to penetrate the electrode modified film and reach the electrode surface, resulting in a greater peak current. UV–vis and water contact angle further proved that C 3 N 4 /Ppy/SA-CD had higher binding ability to d -Trp. In addition, the sensor had good reproducibility and stability, and can be regarded as a promising platform for chiral sensing.
研究领域:
分析化学
·
生物传感技术
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 31
·期 2
·1483-1490
·
IF 2.195
Zhang Nan,Li Jinfeng,Men Xiusen,Li Zhigang,Zhao Hongtao
A novel electromagnetic functionalized Ni@PPy composite was synthesized with a cleaning method. XRD and FTIR analyses showed that the Ni@PPy composite was successfully prepared. SEM, TEM, and HRTEM results proved that Ni nanoparticles, produced by the γ-irradiation-induced reduction method, were wrapped with polypyrrole (PPy) shell to form core–shell structure. There existed many Ni cores in a PPy shell, which could induce more interfacial and dipolar polarization than the structure with one core in a shell. With an increase in Ni content, the dielectric loss was obviously decreased and the magnetic loss had little change. Attenuation constant decreased gradually, which was influenced jointly by conductivity loss and dipolar and interfacial polarization loss. When nPy/nNi/nAPS was 1.75:1:1.75, the as-prepared Ni@PPy composite exhibited the highest microwave absorption (RL max of − 48 dB at 7 GHz and EAB of 3.8 GHz) owing to suitable impedance matching as well as attenuation ability. Therefore, such core–shell structured Ni@PPy composite would be a promising microwave absorber.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Energies
·
2023
·Vol. 16
·期 13
·5112
·
IF 3.2
Jinlin Liu,Yu Wang,Zilong Zhong,Zhou Zhou,Dongliang Chen,Weijie Wang,Shuaixing Mai
Air-conditioning systems account for 40–60% of the energy consumption of buildings, and most of this figure corresponds to the cooling and dehumidification process of air-conditioning units. Compared with traditional compressed air-conditioning systems, solid adsorption dehumidification systems possess good potential to improve indoor air quality and reduce buildings’ energy consumption. However, there are still some problems that prevent the use of solid adsorption dehumidification systems, such as their complexity and high regeneration temperatures. The key to solving the above problem is the discovery of more suitable adsorbents. In this paper, poly N-isopropylacrylamide/polypyrrole (PNIPAm/PPy) hydrogel was selected as the research object, and the performance of the dehumidification material and its potential for application in solid dehumidification systems were studied. It was found that the pore structure of PNIPAm/PPy was relatively complex and that there were abundant pores with uneven pore sizes. The minimum pore size was about 4 μm, while the maximum pore size was about 25 μm, and the pore sizes were mostly distributed between 8 and 20 μm. Abundant and dense pores ensure good hygroscopic and water-releasing properties of the resulting hydrogel. The PPy inside the hydrogel acts as both a hygroscopic and photothermal agent. In an environment with a relative humidity of 90%, 60%, and 50%, the hygroscopic efficiency of PNIPAm/PPy reached 80% in about 75, 100, and 120 min, and the corresponding unit equilibrium hygroscopic capacity values were 3.85 g/g, 3.72 g/g, and 3.71 g/g, respectively. In the initial stage, the moisture absorption increased with the increase in time; then, the increase in moisture absorption decreased. When the temperature was below 40 °C, the hygroscopic performance of PNIPAm/PPy was almost temperature-independent. The PNIPAm/PPy with different thicknesses showed similar moisture absorption efficiency. The lowest desorption temperature of PNIPAm/PPy was 40 °C, which indicates that low-grade energy can be used for material desorption. And the higher the temperature, the faster the desorption rate of PNIPAm/PPy and the higher the desorption amount. It can be seen that the PNIPAm/PPy hydrogel presents good desorption performance and can be used repeatedly.Keywords:heat and mass transfer in porous media;dehumidification material;hydrogel;solid dehumidification system;hygroscopic efficiency;desorption performance
研究领域:
材料科学
·
环境工程
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）