SOLID STATE IONICS
·
2020
·
IF 3.107
Chang Su,Pengju Guo,Lihuan Xu
The Li (tri-(4-carboxyphenyl) amine) (Li-TCPA 2 ) doped polypyrrole (PPy-Li-TCPA 2 ) composites were successfully prepared by in-situ chemical oxidation using pyrrole and Li-TCPA 2 as raw materials. The structure, morphology, electrochemical properties of prepared materials were characterized by fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), specific surface area test (BET), scanning electron microscopy (SEM), cyclic voltammogram (CV) and electrochemical impedance spectra (EIS), respectively. Also, the charge-discharge properties of the prepared composites were studied by galvanostatic charge-discharge testing. The results demonstrated that as-prepared composite material exhibited a reversible redox process at 2.0–4.0 V. And the discharge specific capacity for PPy-Li-TCPA 2 (2:1) and PPy-Li-TCPA 2 (6:1) are 50.4 mAh·g −1 and 63.7 mAh·g −1 as measured at 30 mA·g −1 between 2.0 and 4.0 V, while PPy-Li-TCPA 2 (4:1) exhibited the discharge specific capacity of 91.1 mAh·g −1 , which were remarkably higher than that of the pure PPy (29.5 mAh·g −1 ) under the same experimental conditions. At the same time, PPy-Li-TCPA 2 (4:1) has improved rate performance and stable cycleability. The excellent electrochemical properties are attributed to the introduction of Li-TCPA 2 as dopant , which improved the electrical conductivity and the redox activity of PPy. Furthermore, the resulted well-dispersed particle structure of the composite as well as its improved specific surface area for doped PPy facilitated to the contact of the electrolyte with the active material, leading to the increased utilization ratio of active material and the enhanced electrochemical performances .
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Haibin Wang,Xiaoqiang Du,Xiaoshuang Zhang,Lu Li
Electrocatalytic water splitting has become one of the most promising and effective ways to solve energy crises and environmental pollution. In this work, a series of M-doped Co 3 O 4 materials with foreign ions (M = Ce, Ni and Fe) were grown on a Ni foam substrate through classical hydrothermal and calcination methods. It is worth noting that not all doping of foreign ions can promote the electrocatalytic performance of intrinsic materials. The Ce-doped Co 3 O 4 material shows excellent oxidation properties of water (overpotential of 320 mV at 50 mA cm −2 ) and urea (potential of 1.39 V at 50 mA cm −2 ). However, the doping of Ni reduces the water oxidation performance of the intrinsic material (overpotential of 410 mV@ 50 mA cm −2 ), and the doping of Fe reduces the urea oxidation performance of the inherent material (potential of 1.45 V@ 50 mA cm −2 ). A series of experimental results indicate that the improved activity of the Ce-Co 3 O 4 electrode is attributed to faster electron transport capacity, higher exposure to active sites, and improved conductivity due to doping of Ce. It is noteworthy that the doping of these ions does alter the rate-determination step for the water oxidation reaction. The stability test demonstrated that the current density of water oxidation and urea oxidation of the catalyst had no significant attenuation after a long electrocatalytic activity test. This work provides a new idea for improving the electrocatalytic activity of catalysts by a doping strategy.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2023
·Vol. 11
·期 14
·2300207
·
IF 9
Junjie Deng,Zhihao Guan,Donglei Fu,Yuewei Zheng,Zhengjie Chen,Houbin Li,Xinghai Liu
Room-temperature phosphorescence (RTP) materials are normally prepared by doping guest materials into space-limited host materials to inhibit nonradiative decay. This work aims to prepare a long afterglow excitation-dependent emission RTP material by doping a small amount of 4-carboxyphenylboronic acid into the boric acid matrix, followed by heat-treating. The calculation of density functional theory shows that the electron cloud distribution and electron transfer trend of the selected material reduces the energy requirement to excite the RTP properties of the obtained materials. The obtained RTP materials can be excited by UV light at 310 and 365 nm for dark blue and green phosphorescence emission, respectively. The results demonstrate the long phosphorescence lifetimes of 1.97 and 0.62 s and the high absolute photoluminescence quantum yields of 17.4% and 15.6%. These results show that the obtained RTP materials have potential prospects as information coding and phosphorescent anti-counterfeiting.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2020
·
IF 4.65
MingXing Li,Fangtian You,Chunjun Liang,Zhiqun He
A new temperature measurement strategy based on the luminescence of Ce 3+ and Tb 3+ doped YBO 3 was proposed. Dual emissions of Ce 3+ and Tb 3+ have different thermal dependencies, which can be used to overcome those limitations such as low signal discriminability and large measurement error. A series of Ce 3+ and/or Tb 3+ doped YBO 3 samples were synthesized by hydrothermal method , and the influences of temperature on the photoluminescence (PL) intensity of Ce 3+ 5d-4f transition and Tb 3+ 4f-4f transition were discussed in detail. Compared with the single emission of YBO 3 :1.0%Ce 3+ , fluorescence intensity ratio (FIR) variation of Ce 3+ blue emission and Tb 3+ green emission in YBO 3 :1.0%Ce 3+ , 1.0%Tb 3+ has been studied as a function of temperature in the range of 288–328 K. The absolute sensitivity of YBO 3 :1.0%Ce 3+ , 1.0%Tb 3+ was 1.18 %K −1 , higher than that of YBO 3 : 1.0%Ce 3+ (0.70 %K −1 ). The results suggest that YBO 3 :Ce 3+ , Tb 3+ is a good candidate as optical thermometry in the physiological range.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2025
·
IF 4.2
Mingen Ma,Gang Yang,Mengmeng Dai,Xiumei Xu,Xiaochong Wang,Shaobo Cui,Yongsheng Zhu
Rare earth doped nanomaterials have attracted considerable attention in photonics and information security due to their tunable multicolor luminescence and rapid response properties. However, achieving dual-mode luminescence with tunable emission colors in a single material remains a significant challenge. Herein, NaYF 4 :Yb/Ho/Ce@NaYF 4 :Ce/Tb core-shell nanocrystals were synthesized, which exhibit dual-excitation response under both 254 nm ultraviolet and 980 nm near-infrared light sources. This innovative design facilitates tunable upconversion luminescence through the cross-relaxation process between Ce 3+ and Ho 3+ ions in the inner cores. Moreover, the system exhibits synergistic downshifting luminescence attributed to the energy transfer from Ce 3+ to Tb 3+ ions in the shells. By combining upconversion and downshifting luminescence, this dual-functional platform delivers a versatile and highly efficient solution for advanced security-related applications.
研究领域:
材料科学
·
纳米科技
·
光子学
·
信息安全部件
·
发光材料
✓ 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）