FERROELECTRICS
·
2024
·
IF 0.6
Zhao Hong,Xu Dan,Yu Taolin,Duan Xiaoyang,Zhou Xinyuan,Zhao Wenjie,He Jun
The effects of Li/Er and Li/Bi co-substitution on the structure, dielectric, and ferroelectric properties of BaTiO3 (BT) ceramics were investigated and analyzed. X-ray diffraction measurements show that the doped samples have a single tetragonal structure without secondary phases. Rietveld refinement results show that the Li/Er and Li/Bi ions tend to replace A-sites of BT lattices at low doping content. As the doping content increases, the Curie temperature moves to the high-temperature region due to the increased tetragonality and internal stress. Compared with the undoped ceramics, the ferroelectric properties of the doped ceramics are improved. The enhanced remnant polarization is attributed to the combined effects of large grain modulation and defect dipole arrangement.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Hanchen Wang,Lijia Jia,Biao Huang,Qi-Lin Lu
The construction of N, P co-doped hierarchically porous carbons (NPHPC) by a facile and green approach is crucial for high-performance energy storage but still an enormous challenge. Herein, an environment-friendly “ in-situ co-doping, self-regulation-activation” strategy is presented to one-pot synthesize NPHPC using a phytic acid-induced polyethyleneimine/chitosan gel (PEI-PA-CS) as single precursor. NPHPC displayed a specific surface area of up to 1494 m 2 g −1 , high specific capacitance of 449 F g −1 at 1 A g −1 , outstanding rate capability and cycling durability in a wide temperature range (−20 to 60 °C). NPHPC and PEI-PA-CS electrolyte assembled symmetric quasi-solid-state flexible supercapacitor presents superb energy outputs of 27.06 Wh kg −1 at power density of 225 W kg −1 . For capacitive deionization (CDI), NPHPC also exhibit an excellent salt adsorption capacity of 16.54 mg g −1 in 500 mg L −1 NaCl solution at a voltage of 1.4 V, and regeneration performance. This study provides a valuable reference for the rational design and synthesis of novel biomass-derived energy-storage materials by integrating phytic acid induced heteroatom doping and pore engineering.
研究领域:
材料科学
·
能源存储
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemElectroChem
·
2020
·Vol. 7
·期 14
·3116-3122
·
IF 4.154
Sheng Song,Xiaoming Zhang,Xinlong Xu,Chuchu Wu,Huanqiao Li,Zhangxun Xia,Shansheng Yu,Suli Wang,Gongquan Sun
Graphical Strat talks : The density of FeN x active sites is increased by co-doping with trace Cu atoms. The as-prepared 20Fe10Cu-NC electrocatalyst exhibits outstanding oxygen reduction reaction performance in both alkaline and acid conditions. Iron-nitrogen-doped carbon (Fe-NC) is an ideal candidate to replace Pt-based oxygen reduction reaction (ORR) electrocatalysts due to its low cost and comparably high intrinsic activity. To further enhance the ORR performance of Fe-NC electrocatalysts, efforts have been focused on two main methods. One is to enhance the intrinsic activity of FeN x sites through electronic and geometric regulation, and the other is to increase the density of active sites by introducing high-nitrogen-containing precursors or co-doping methods. Herein, we report a strategy to further increase the Fe loading through the introduction of a trace amount of Cu atoms. Significant enhancement of the electrocatalytic ORR property is observed in the as-prepared Fe and Cu co-doped electrocatalyst with superior half-wave potential (E 1/2 ) in both alkaline and acid electrolyte. Experimental and theoretical study reveals that the introduction of a trace amount of Cu atoms is beneficial for the formation of FeN 4 sites, owing to the reduced formation energy. This work opens up a wide avenue to further increase the Fe loading in Fe-NC electrocatalysts through bimetal co-doping method.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2020
·
IF 2.779
Xingzhen Huang,Kan Huang,Liken Chen,Nan Chen,Ruoshan Lei,Shilong Zhao,Shiqing Xu
The Y 2 Ti 2 O 7 : Er 3+ /Yb 3+ phosphors co-doped with Li + and Li + /Mg 2+ ions were prepared via solid state reaction method. The effects of Li + and Mg 2+ co-doping on the structure and morphology of Y 2 Ti 2 O 7 : Er 3+ /Yb 3+ phosphors were investigated by X-ray diffraction (XRD), electron paramagnetic resonance (EPR) spectra and field emission scanning electron microscopy (FESEM) observations. The 980 nm excitation assisted UC luminescence intensity for green and red band was enhanced by 8.7 and 14.3 times respectively after co-doping with Li + /Mg 2+ ions in Y 2 Ti 2 O 7 : Er 3+ /Yb 3+ , which could be explained based on the variations in crystal structure and particle size. Using the fluorescence intensity ratio (FIR) technique, the impact of 980 nm pump power on the thermometric behaviors was studied based on the thermally coupled levels of 2 H 11/2 and 4 S 3/2 of Er 3+ ions. Due to the unique thermal properties of the Y 2 Ti 2 O 7 host, the temperature increment caused by laser thermal effect was minimized, benefiting the consistency of FIR data over a wide range of pump power density. Besides, a high relative sensor sensitivity of 1.17%K −1 was obtained for Y 2 Ti 2 O 7 : Er 3+ /Yb 3+ /Li + /Mg 2+ phosphors. These characteristics may make the studied system applicable for optical temperature sensor with high accuracy.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 12
·4685-4694
·
IF 4.569
Guixian Li,Yu Xue,Qinan Mao,Lang Pei,Hong He,Meijiao Liu,Liang Chu,Jiasong Zhong
Luminescent thermometers provide a non-contact method of probing temperature with high sensitivity and response speed at the nanoscale. Synergistic photoluminescence from different activators can realize high sensitivity for luminescent thermometers by finely selecting ions with specific crystallographic sites. Herein, the more temperature-sensitive Mn4+ and the less-sensitive Eu3+ (or Sm3+) activators are co-doped into a Ca2GdSbO6 matrix to form an effective thermometer, where Mn4+ and Eu3+ (or Sm3+) ions occupy the Sb5+ and Gd3+ sites, respectively. The co-doping of Eu3+ ions or Sm3+ ions leads to lattice expansion of Ca2GdSbO6 matrix and a tuned narrow emission from deep-red to orangish-red. According to the ratio of luminescence intensity, the maximal Sa and Sr values are 0.19 K−0 (347 K) and 1.38% K−( (420 K) for Ca2GdSbO6:Mn4+/Eu3+ probe and 0.26 K−p (363 K) and 1.55% K−( (430 K) for Ca2GdSbO6:Mn4+/Sm3+ probe thermometers, respectively. In addition, thermometers based on Mn4+ emission lifetimes can provide the highest relative sensitivity of 1.47% K−s at 425 K. Thus, the highly-temperature-sensitive Ca2GdSbO6:Mn4+/(Eu3+ or Sm3+) phosphor is a promising candidate for practical luminescence thermometers.
研究领域:
材料科学
·
无机化学
·
光学材料
·
纳米技术
·
生物传感
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2016
·Vol. 26
·期 33
·6025-6032
·
IF 11.382
Yuyang Li,Guanghua Liu,Tengfei Cao,LiMin Liu,Jiangtao Li,Kexin Chen,Laifeng Li,Yemao Han,Min Zhou
Dense bulk samples of (Ag,In)-co-doped Cu 2 SnSe 3 have been prepared by a fast and one-step method of combustion synthesis, and their thermoelectric properties have been investigated from 323 to 823 K. The experimental results show that Ag-doping at Cu site remarkably enhances the Seebeck coefficient, reduces both electrical and thermal conductivities, and finally increases the figure of merit (ZT) value. The ZT of the Cu 1.85 Ag 0.15 SnSe 3 sample reaches 0.80 at 773 K, which is improved by about 70% compared with the unadulterated sample (ZT = 0.46 at 773 K). First principle calculation indicates that Ag-doping changes the electronic structure of Cu 2 SnSe 3 and results in larger effective mass of carriers, thus enhancing the Seebeck coefficient and reducing the electrical conductivity. The low electrical conductivity caused by Ag-doping can be repaired by accompanying In-doping at Sn site, and by (Ag,In)-co-doping the thermoelectric properties are further promoted. The (Ag,In)-co-doped sample of Cu 1.85 Ag 0.15 Sn 0.9 In 0.1 Se 3 shows the maximum ZT of 1.42 at 823 K, which is likely the best result for Cu 2 SnSe 3 -based materials up to now. This work indicates that co-doping may provide an effective solution to optimize the conflicting material properties for increasing ZT.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Materials Research Express
·
2018
·Vol. 5
·期 10
·106203
·
IF 1.151
Tao Pang,Wenbo Peng
Upconversion luminescence of Yb3+/Er3+ and Yb3+/Tm3+ co-doped Y2(MoO4)3 phosphors under 980 nm excitation is investigated. It is demonstrated that Yb3+ co-doping causes a significant thermal effect. For Yb3+ and Er3+ co-doped case, the thermal effect, the long-distance energy migration and the energy transfer from Er3+ to Yb3+ are responsible for the abnormal luminescence quenching. In the case of Yb3+ and Tm3+ co-doped, the thermal effect improves the excited efficiency of Tm3+, and thus the luminescence of Tm3+ continues to strengthen at the Yb3+ concentration that causes Er3+ luminescence quenching. These results contribute to the design of the efficient upconversion materials.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
OPTIK
·
2017
·
IF 0.835
Renping Cao,Jijun Huang,Xiangfeng Ceng,Zuofu Hu,Ting Chen,Wen Hu,Xinqin Zhang
Ca 3 Nb 2 O 8 :Sm 3+ phosphor is synthesized by solid-state reaction method in air. Host Ca 3 Nb 2 O 8 emits blue light with excitation 260 and 314 nm, and its emission band peaking at ∼460 nm is attributed to the 3 T 1,2 → 1 A 1 transations in [Nb 2 O 8 6− ] group. Ca 3 Nb 2 O 8 :Sm 3+ phosphor with excitation 314 nm shows a systematically tunable emission by adjusting Sm 3+ ion concentration , and only emits reddish-orange light with excitation 407 nm. Excitation band indicates that Ca 3 Nb 2 O 8 :Sm 3+ phosphor may be effectively excited by (∼407 nm) near ultraviolet light-emitting diode chip. The optimal Sm 3+ ion concentration is ∼5 mol% in Ca 3 Nb 2 O 8 :Sm 3+ phosphor. Emission intensity of Ca 3 Nb 2 O 8 :Sm 3+ phosphor may be increased ∼1.4 times by co-doping Li + ions as charge compensator and fluxing agent roles. The experimental results will contribute to studying novel Sm 3+ -doped luminescent materials.
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
·
2022
·
IF 6.371
Xing Yang,Jun Guo,Zi-Yuan Wang,Wen-Hao Gu,Quan Shan,Jing Feng,Zhen-Hua Ge
Bi 2 S 3 -based materials with low thermal conductivity and high Seebeck coefficient has been regarded as promising thermoelectric materials for years. To optimize the thermoelectric properties of Bi 2 S 3 materials, (Se, Cl)-co-doped nanostructured Bi 2 S 3 bulks were prepared by hydrothermal method combined with spark plasma sintering . The doping contents of Se and Cl in Bi 2 S 3 depend on the reaction time of the hydrothermal process. A high power factor of 450 μWm −1 K −2 was achieved for Bi 2 S 3 sample with the reaction time of 24 h owing to the substitution of S by Se and Cl. Meanwhile, a low thermal conductivity of 0.35 Wm −1 K −1 is obtained for the Bi 2 S 3 sample with the reaction time of 18 h, owing to the strong phonon scattering caused by the high density of grain boundaries, pores and point defect . Therefore, benefiting from the improved electrical transport properties and reduced thermal conductivity, a peak ZT value of ~ 0.57 was obtained at 673 K for the Bi 2 S 3 sample with the reaction time of 24 h.
研究领域:
材料科学
·
热电材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 56
·期 7
·4727-4740
·
IF 3.553
Deng Shuping,Jiang Xianyan,Chen Lili,Zhang Ziye,Qi Ning,Wu Yichu,Chen Zhiquan,Tang Xinfeng
In this paper, we reported the enhanced thermoelectric properties of Cd and Sn dual-doped Cu 3 SbSe 4 -based material prepared by the vacuum melting combined with spark plasma sintering process. X-ray photoelectron spectroscopy studies revealed the presence of Cu + , Cd 2+ , Sb 5+ , Sn 4+ and Se 2− states of Cu, Cd, Sb, Sn and Se, respectively. All samples exhibited p -type conduction with carrier concentrations varying from 0.54 × 10 18 to 46.42 × 10 18 cm −3 , while carrier mobility changes from 18.2 to 46.6 cm 2 V −1 s −1 at room temperature. Cd doping at Cu sites in the Cu 3 SbSe 4 can reduce the lattice thermal conductivity, while Sn doping at Sb sites is effective to adjust the carrier concentration. The further reduction in thermal conductivity is observed in Cd-Sn co-doped samples resulting from an accumulated effect combining point defects and the secondary-phase CdSe. Consequently, the maximum dimensionless figure of merit ( ZT ) value reaches 0.66 at 623 K for the Cu 2.75 Cd 0.25 Sb 0.94 Sn 0.06 Se 4 sample, which is 190% larger than that of the intrinsic sample ( ZT of 0.35). The findings provide an alternative strategy of boosting the carrier and phonon transports of the Cu 3 SbSe 4 , which is also a meaningful guidance to achieve high performance in other copper-based chalcogenides.
研究领域:
材料科学
·
凝聚态物理
·
无机非金属材料
·
热电转换
·
半导体物理
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Xuan Yang,Xueqin Wang,Shenghao Xu,Beili Lu,Biao Huang,Xinyu Zheng,Guanfeng Lin
Hydroquinone (HQ) in wastewater is of great concern, as it is harmful to human health and threatens the ecological environment. However, the existing adsorbents have low adsorption capacity for HQ. To improve the removal of HQ, N,S-codoped activated carbon-ZIF-67 (NSAC-ZIF-67@C) was synthesized in this study by in situ growth of ZIF-67 on N,S-codoped activated carbon (NSAC) and carbonization. The influence of pH, contact time, and initial concentration on the adsorption behaviors of NSAC-ZIF-67@C on HQ were investigated. Owing to the synergistic effect of abundant active sites and well-developed pore structure, the NSAC-ZIF-67@C achieved a prominent adsorption capacity of 962 mg·g–1 and can still retain high adsorption performance after 5 cycles for HQ, which is superior to that of reported other adsorbents. HQ adsorption follows the pseudo-second-order kinetics model (R2 = 0.99999) and the Freundlich isotherm model. X-ray photoelectron spectroscopy (XPS) analysis before and after adsorption as well as density functional theory (DFT) calculation results showed that pyridinic-N-termini were conducive to the π–π interactions and hydrogen-bonding interactions. Therefore, the adsorption mechanisms of NSAC-ZIF-67@C on HQ involve pore filling, electrostatic attraction, π–π interaction, and hydrogen bonding. This study is expected to provide a reference for designing highly effective adsorbents for wastewater treatment.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 4
·3097-3101
·
IF 3.201
Qiaoling Liu,Nan Zhang,Haoying Shi,Wenyan Ji,Xiaoqian Guo,Wen Yuan,Qin Hu
Highly fluorescent carbon dots (CDs) are prepared by a one-step microwave heating method using citric acid, L-cysteine and dextrin as the precursors. The average size of the CDs is 2.61 nm with good water dispersibility and photostability. Compared with undoped CDs, small amounts of nitrogen (N) and sulfur atom (S) co-doped CDs exhibit a red shift of the absorption spectra to the visible region and lead to a high quantum yield of 22%. Due to the large amount of carboxyl and hydroxyl groups (−COOH and −OH) on the surface of the CDs, Cu2+ is selectively detected in aqueous solution at pH 7.0 with a detection limit as low as 20 nM, which is much lower than the maximum concentration of Cu2+ in drinking water (∼20 μM) permitted by the US Environmental Protection Agency (EPA). Moreover, the application in tap water samples further demonstrates that the as-synthesized CDs are good candidates for the monitoring of Cu2+ in environmental water samples.
研究领域:
分析化学
·
环境科学
✓ 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）