JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2015
·Vol. 26
·期 9
·6776-6780
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IF 1.569
Cao Renping,Xu Haidong,Peng Dedong,Gou Qingdong,Zhou Shenlin,Liu Pan,Yu Xiaoguang
BaWO 4 :Sm 3+ , Mo 6+ /K + phosphors are synthesized by a high temperature solid-state reaction method in air. The very strong emission bands peaking at ~600 and 644 nm and the strongest excitation band peaking at ~403 nm are assigned to the 4 G 5/2 → 6 H J (J = 7/2 and 9/2) and 6 H 5 / 2 → 4 F 7 / 2 transitions of Sm 3+ ion, respectively. The optimal Sm 3+ doping concentration is ~5 mol%. Emission intensity of BaWO 4 :Sm 3+ phosphor is increased more than twice owing to charge compensation when the K + ion is codoped as charge compensator, however, Mo 6+ ions is small influence to its emission intensity. The energy transfers and luminous mechanism are explained by using energy level diagrams of WO 4
2− group and Sm 3+ ion. Lifetimes of Ba 0.925 WO 4 :0.05Sm 3+ , Ba 0.925 W 0.9 Mo 0.1 O 4 :0.05Sm 3+ , and Ba 0.9 K 0.05 WO 4 :0.05Sm 3+ phosphors with excitation 403 nm are about 0.933, 0.882, and 0.693 ms, respectively. The experiment results indicate that BaWO 4 :Sm 3+ , Mo 6+ /K + phosphors will be a potential red phosphor candidate for white LEDs based on near UV (~403 nm) LED chip and research contents are useful to improve luminescence properties of Sm 3+ -doped phosphors.
研究领域:
材料科学
·
光学
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产品关联
DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Yuhong Zhang,Nan Zhang,Pengcheng Wang,Xingke Zheng,Yibin Guo,Hang Liu
In this work, tungstate BaWO 4 phosphors doped Ho 3+ -Yb 3+ -Gd 3+ ions are successfully synthesized through solid-state reaction method. Under the excitation of a 980 nm laser, the up-conversion (UC) luminescence properties are investigated simultaneously. The blue (465 nm, 489 nm), green (541 nm) and red (665 nm) emission intensities of BaWO 4 : Ho 3+ /Yb 3+ /Gd 3+ samples are dramatically enhanced by 20.59, 9.83, 7.37, and 27.59 times more than those without Gd 3+ ions. The possible reason is discussed, which attributes to the energy transfer efficiency enhancement from Yb 3+ to Ho 3+ due to the lattice expansion induced by Gd 3+ ions. The temperature-sensing properties of BaWO 4 : Ho 3+ /Yb 3+ /Gd 3+ samples are also discussed based on the fluorescence intensity ratio (FIR) technology. The sensitivity of temperature measurement for BaWO 4 : Ho 3+ /Yb 3+ /Gd 3+ sample is higher than that of BaWO 4 : Ho 3+ /Yb 3+ . It proves that the codoped Gd 3+ ions can also increase the temperature sensitivity because the higher UC emission efficiency will lead to a high signal-to-noise ratio. The result provides an effective way to design UC luminescence materials with high temperature sensing properties.
研究领域:
材料科学
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光学材料
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发光学
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传感器技术
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无机功能材料
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2026
·
IF 9.2
Zhendian Li,Yuan Ha,Ziqi An,Xian Cao,Linzhuang Xing,Zhimin Li
Achieving exceptional electrocatalytic activity in conventional low-cost materials is of great significance but remains highly challenging. BaWO4 is recognized for its favorable stability and corrosion resistance in acidic/alkaline media, while intrinsically exhibiting limited activity for the electrocatalytic hydrogen evolution reaction (HER) due to its low electrical conductivity and insufficient active sites for optimal hydrogen adsorption/desorption kinetics. Herein, we report the successful activation of a BaWO4 ceramic as a binder-free HER self-catalytic electrode via atomic-level Ni doping. The incorporation of trace amounts of Ni effectively modulates the electronic structure and surface morphology of the BaWO4 self-catalytic ceramic, significantly enhancing charge transfer capability and exposing more catalytically active sites, thereby endowing it with improved intrinsic catalytic properties. As a result, the Ni-doped BaWO4 (Ni0.01-BaWO4) ceramic electrode delivers an outstanding HER performance with a low overpotential of 122 mV at 10 mA cm−2 in alkaline media, outperforming the undoped BaWO4 (287 mV), and retains good durability with negligible degradation over 500 hours of continuous operation. Combined experimental analyses and density functional theory (DFT) calculations reveal that Ni doping lowers the energy barrier for H2O dissociation by weakening H–OH adsorption and facilitating hydroxyl desorption, thereby improving overall HER kinetics. Notably, the catalyst exhibits superior structural integrity and long-term operational stability under harsh electrochemical and ultrasonic conditions. This work presents an effective approach to activate inert ceramic electrodes, achieving improved electrocatalytic activity and durability for practical HER applications.
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DOI
高影响因子
LANGMUIR
·
2018
·
IF 3.789
Wen Deng,Fengjun Chun,Wen Li,Hai Su,Binbin Zhang,Meilin Xie,Haitao Zhang,Xiang Chu,Long Jin,Chao Luo,Weiqing Yang
Scheelite-structure tungstates with unique structural features and excellent luminescence possess promising applications, such as light-emitting diodes (LEDs), scintillators, and displays. The controllable growth of high quality and uniform composition thin films mounted on cheap substrates is a key factor to realize the above commercial applications, however, which is also a big challenge due to the difficult stress release stemming from intrinsic lattice mismatches. Here, we employed the simple and composition-controlled polymer-assisted deposition (PAD) method to successfully obtain a series of high quality and well-proportioned BaWO4:Eu3+ (BWOE) thin films with red emission. Screening out the unbound freedom metal ions by poly(ether imide) (PEI) and ethylene diamine tetraacetic acid (EDTA), the firmly bound metal ions (Ba2+, W6+ and Eu3+) in polymer solution were applied to accurately control the chemical composition and effectively governed the release of stress during the growth process of BWOE thin films. Furthermore, XRD, SEM and EDS mapping detections evidently authenticated the quasi-single crystallinity, uniform morphology and well-distributed composition of as-grown thin films. Additionally, excited by 250 nm light, these thin films could efficiently produce the red emission, peaked at around 612 nm originated from the 5D0 → 7F2 transition of Eu3+. Moreover, the optimal doping concentration of thin films was confirmed to be 9% and corresponding Commission International de l’Eclairage (CIE) chromaticity coordinate was (0.618, 0.365), which evidently implied the excellent color rending index. Therefore, this work highlights the rather superior PAD method to prepare uniform and high-quality BWOE thin films, which can be expanded toward the other photoelectric devices including white lighted-emitting diodes, scintillators, displays, and photoelectric detectors.
研究领域:
材料科学
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光电子学
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发光材料
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薄膜技术
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固态化学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
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2024
·
IF 18.5
Yang Gao,Min Fu,Shuang Zhao,Zhongyu Hou,Kechen Liu,Xiangbo Deng,Zetian Tao
One of the key challenges for high-performance proton-conducting solid oxide fuel cells (H-SOFCs) is the mismatch in thermal expansion coefficients (TEC) between the cathode and electrolyte. While incorporating negative thermal expansion (NTE) materials can mitigate this issue, mechanical mixing often weakens cathode strength. To address this, a TEC gradient cathode is proposed and successfully implemented by co-sintering PrBa(Co 0.7 Fe 0.3 ) 2 O 5-δ (PBCF) with Y 2 W 3 O 12 (YWO) in this work. In this work, Ba atoms at the A-site of PBCF migrated from the lattice, generating A-site defects. The resulting BaWO 4 and Y 10 W 8 O 21 phases, which have low TEC, are uniformly distributed between PBCF and YWO, forming a TEC gradient composite cathode. In addition, the transition phase captures the A-site element Ba in the electrolyte layer, optimizing the electrolyte-cathode interface. The composite cathode exhibits a reduced TEC, closely matching that of the electrolyte, significantly enhancing interface bonding, thereby providing a lower ohmic resistance of 0.051 Ω cm 2 and a higher power density of 1.88 W cm −2 at 700 °C. Remarkably, thermal cycling tests conducted under temperature switching conditions demonstrate the composite cathode's long-term thermal and chemical stability.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
·
IF 5.8
Yuxuan Ren,Junxian Wang,Yunfeng Guo,Di Li,Jiamao Li
The influences of Mo 6+ substitution at the B-site of scheelite structure on the sintering character, microstructures, lattice vibrational characteristics, and dielectric properties of BaW 1- x Mo x O 4 ( x = 0.10–0.30) ceramics were studied in detail in this paper. The sintering temperature of BaW 1- x Mo x O 4 ceramics was effectively reduced to less than 950 °C through forming a scheelite solid solution. The densification and the quality factor ( Q × f ) of BaW 1- x Mo x O 4 ceramics were also enhanced compared with pure BaWO 4 ceramic. Raman spectroscopy confirmed that the dielectric constant (ε r ) was highly correlated with molecular polarizability, and the Q × f was strongly dependent on the symmetric stretching bond of [WO 4 ] tetrahedron. Oxygen bond valence was one of crucial parameters for modulating the temperature coefficient of resonant frequency (τ f ). Interestingly, the BaW 0.75 Mo 0.25 O 4 ceramic sintered at 910 °C exhibited favorable microwave dielectric properties of ε r = 9.44, Q × f = 46,820 GHz (@12.5 GHz), and τ f = −69.2 ppm/°C. Meanwhile, the BaW 0.75 Mo 0.25 O 4 ceramic had stupendous dielectric properties in low-frequency band: ε r = 17.5 and dielectric loss (tan δ ) = 2.2×10 −4 (@10 MHz). In addition, there was good chemical compatibility between BaW 0.75 Mo 0.25 O 4 ceramic and silver electrodes. These findings evidence that BaW 1- x Mo x O 4 ceramics are competitive candidates in LTCC technology.
研究领域:
材料科学
·
电子材料
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 46
·16310-16315
·
IF 6.4
Guotao Xiang,Zhen Liu,Zhiyu Yang,Yongjie Wang,Lu Yao,Sha Jiang,Xianju Zhou,Li Li,Xiaojun Wang,Jiahua Zhang
High-efficiency upconversion (UC) luminescence has been a hot topic in the development of optical materials. In this study, an extremely strong green UC is successfully achieved in the BaWO4:Yb3+/Er3+ phosphor through engineering the local environment around the luminescent centers, realized by Ca2+ doping. The green UC intensity of Ca2+ doped BaWO4:Yb3+/Er3+ is 6.5 and 2.3 times stronger than that of BaWO4:Yb3+/Er3+ and CaWO4:Yb3+/Er3+, respectively. Eu3+ ions are employed as the structure probe to detect the evolution of the crystal field symmetry with the increase of Ca2+ doping concentration, the results of which match well with the corresponding variation of the UC spectra. Meanwhile, the BaWO4:Yb3+/Er3+/Ca2+ exhibits excellent temperature sensing performance based on the fluorescence intensity ratio (FIR) between the thermally coupled 2H11/2 and 4S3/2 states of Er3+ ions. Its absolute sensitivity and relative sensitivity for optical thermometry can reach 1.21% K−1 and 1.31% K−1, outperforming the majority of the same type optical thermometers. The temperature resolution of the present thermometer remains lower than 0.1 K within the temperature range of 298 K to 573 K. The intense green UC luminescence along with the outstanding thermal properties makes the BaWO4:Yb3+/Er3+ phosphor a promising candidate for optical thermometry.
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）