Materials Today Communications
·
2023
·
IF 3.8
Zhuo Xing,Juhai Weng,Chi Ma
A series of Zn 2- x Cu x GeO 4 ceramics were prepared by the solid-phase sintering method. Cu 2+ substitution for Zn 2+ facilitated the single-phase formation and benefited densification via lowering the sintering temperatures , hence thereby the microwave dielectric properties were largely improved. A representative composition with x = 0.08 revealed a homogenous Zn 2 GeO 4 phase with good microwave dielectric properties: ε r ∼ 7.47, Q × f ∼ 56,980 GHz, and τ f ∼ −13.9 ppm/°C when sintered at 1000 °C. To evaluate the potential application of low-temperature cofired ceramics (LTCC), sintering aids (B 2 O 3 ) were added to the x = 0.08 sample to reduce its sintering temperature to below 960 °C. A dramatic improvement in Q × f ∼ 107,415 GHz was observed with only 0.5 wt % B 2 O 3 addition. Chemical compatibility was confirmed via cofiring with silver electrodes at 940 °C. All the merits show promising potential for advanced substrates.
研究领域:
材料科学
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Hanzhi Yao,Yuchi Zhang,Yan Xu
Self-calibrated optical luminescent thermometers were prepared based on Eu 3+ /Mn 2+ co-doped Zn 2 GeO 4 phosphors with controllable morphology via a facile hydrothermal synthesis process. The co-doped concentration of Eu 3+ ions in Zn 2 GeO 4 :Mn 2+ played important roles in the evolution of the morphology and the formation of the dual luminescent emission mode. Depending on different excitation wavelengths ranging from 260 to 360 nm, the dual emission centers located at about 534 nm and 612 nm were ascribed to d - d transition derived from 4 T 1 - 6 A 1 of Mn 2+ ions and f - f transition originated from 5 D 0 - 7 F 2 of Eu 3+ ions, respectively, which gave rise to the excellent self-calibrating temperature sensing functions. The related luminescent and sensing mechanism of the Eu 3+ /Mn 2+ co-doped Zn 2 GeO 4 phosphors are also proposed. The as-obtained Eu 3+ /Mn 2+ co-doped Zn 2 GeO 4 phosphors had a high relative sensitivity ( S r ) of 1.96% ºC −1 between 20 and 80 °C, as well as stable reusability, demonstrating its superiority as a ratiometric luminescent thermometer for temperature sensing applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2017
·
IF 3.473
Yanshen Li,Ankang Zhao,Chunyan Chen,Cuimiao Zhang,Jinyu Zhang,Guang Jia
A variety of uniform and well-dispersed one-dimensional Zn 2 GeO 4 :Mn 2+ phosphors have been synthesized via a facile solvothermal process with H 2 O/EG as solvent. During the synthesis process, the component of solvent and the addition of PEG surfactant play an important role in determining the structure, particle size, and morphology of the final product. Under ultraviolet light excitation, the pure Zn 2 GeO 4 sample shows bluish-white emission which is attributed to the native defects present in the Zn 2 GeO 4 host. When Zn 2+ ions are partially substituted by Mn 2+ , the as-synthesized Zn 2 GeO 4 :Mn 2+ samples exhibit intense green emission that corresponds to the d-d transition ( 4 T 1 → 6 A 1 ) of Mn 2+ ions. The luminescence mechanisms of the Zn 2 GeO 4 :Mn 2+ samples were investigated in detail by using the CASTEP code based on density functional theory (DFT). It is expected that the as-synthesized Zn 2 GeO 4 :Mn 2+ phosphors can be potentially applied in lighting, optical displays, and optoelectronic devices .
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
OPTIK
·
2021
·
IF 2.443
Simin Cui,Yiran Jiao,Jiangyong Liu,Yuan Pu,Jie-Xin Wang,Dan Wang
Deep-ultraviolet (DUV) light devices are receiving widely attention due to their potential use in sterilization and water purification , in particularly, during the COVID-19 pandemic. Photoluminescence detectors that demonstrate the existence of DUV light invisible to our eyes are of importance. Herein, we propose a process intensified approach via high-gravity reactive precipitation combined with hydrothermal synthesis for production of Mn 2+ doped zinc orthogermanate (Zn 2 GeO 4 : Mn 2+ ) nanophosphors for deep-ultraviolet detecting. The rotating packed bed (RPB) was used as the reactor for process intensification of the reactive precipitation and the whole processing time was significantly reduced. The Zn 2 GeO 4 : Mn 2+ phosphors show green emission upon ultraviolet or near ultraviolet excitation. In optimized conditions, the products show a sub-microrod morphology with average size of about 200 nm. Under the excitation of 254 nm light, the Zn 2 GeO 4 : Mn 2+ nanophosphors exhibit bright green emission at peak wavelength of 535 nm.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Xiaochun Hou,Chengxue Du,Qing Pang,Chaoyang Jia,Xiaojun Wang,Dangli Gao
Up-conversion persistent luminescence (UCPL) nanoparticles have captured tremendous attention due to their unique optical operating performance such as the absence of auto-fluorescence and the charging capacity of near-infrared (NIR) light. However, the weak afterglow intensity as well as low duration limits their practical applications including multimode anti-counterfeiting and biological imaging, etc. Herein, typical green persistent luminescence (PersL) and photo-stimulated luminescence (PSL) of Zn 2 GeO 4 :Mn 2+ phosphors were enhanced via non-equivalent Li + co-doping, in which the preferred site selection of Mn 2+ and Li + have been verified by using the first-principles theory. The possible luminescent enhancement mechanisms were proposed based on improving the oxygen vacancy density and promoting the formation of Mn 4+ defect energy level in bandgap structure by non-equivalent doping of Li + . Interestingly, UCPL of Zn 2 GeO 4 :Mn 2+ ,Li + can be achieved after charging of Vis to NIR light. It is worth noting that this UCPL can be further enhanced by the sensitization of NaYF 4 :Yb,Tm nanoparticles via simply mixing Zn 2 GeO 4 :Mn 2+ ,Li + and NaYF 4 :Yb,Tm under 980 laser stimulation. As a result, Zn 2 GeO 4 :Mn 2+ ,Li + phosphor exhibits the enhanced quintuple-mode luminescence including photoluminescence , PersL, PSL, photo-stimulated persistent luminescence and UCPL. In particular, the achieved NIR rechargeable UCPL hybrid phosphors exhibit enormous potential for higher order anti-counterfeiting and rewriteable data encryption and decryption applications.
研究领域:
材料科学
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光学工程
·
纳米技术
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产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2020
·Vol. 22
·期 18
·10265-10277
·
IF 3.43
Yongli Wang,Mingyue Zheng,Hongkai Zhao,Hao Qin,Weiliu Fan,Xian Zhao
Interface engineering has been regarded as a promising strategy for enhancing the catalytic activities of heterojunction photocatalysts. Herein, we have adopted an in situ etching sulfurization method to construct a Zn2GeO4−x/ZnS intimate heterojunction, which exhibited excellent photocatalytic H2 production in the absence of a Pt co-catalyst. Distinctively, TEM and HRTEM measurements showed that the interface of the Zn2GeO4−x/ZnS heterojunction became rough (topologically) due to in situ etching sulfurization, and etching was found to be strongly dependent on the crystal orientation. Moreover, the surface of the Zn2GeO4 nanorods from flat (100) planes evolved into an irregular coastline-like structure topologized with (110) and (113) high-index planes. ICP and elemental distribution measurements indicated that during the precipitation of ZnS via in situ etching sulfurization, the migration and dissolution of Zn and Ge ions on the Zn2GeO4(100) plane led to the roughening of the interface and the evolution of crystal planes. XPS and EPR analyses showed that Zn2GeO4−x/ZnS contained more oxygen vacancies with structural evolution. The theoretical calculations demonstrated that oxygen defects were prone to be generated on the Zn2GeO4(113) plane and formed the Ge3c3+–VO complexes. Compared to the inactive (100) plane, etching caused the Zn2GeO4(110) planes to have a higher number of threefold coordinated germanium (Ge3c4+) and (113) high-index planes that possessed abundant active sites (Ge3c3+–VO complexes), which dramatically decreased the barrier and reaction energy of H2O dissociation. This work not only provides fundamental insights into the topological interface evolution and facet-dependent defect distribution but also offers a strategy for the design of efficient photocatalysts for H2 production without the use of Pt as a co-catalyst based on a multifunctional interface.
研究领域:
材料科学
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能源化学
·
表面科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Sustainable Energy & Fuels
·
2022
·Vol. 6
·期 19
·4520-4527
·
IF 6.813
Jian Hao,Jun Bai,Jing Wang,Lu Xu,Junli Guo,Caixia Chi,Haihong Li
The large volume changes of Ge-based electrode result in poor electrochemical cycling and rate performance and are the important factors hampering the practical implementation of Ge-based materials in Li-ion batteries (LIBs). Here we fabricated a fascicular structure Ge/Zn2GeO4 (Ge/Zn2GeO4NFs) by an in situ growth of flower-like Zn2GeO4 on micron-sized Ge. In an EDTA/water solvent system, Zn2GeO4 were generated on the Ge substrate, and self-assembled into a flower-like structure through coordination and H-bonding. Benefiting from the improved structural stability and abundant transmission channels of lithium ions and electrons, the as-fabricated Ge/Zn2GeO4NFs anodes exhibited excellent cyclability and rate performance. At a current density of 0.2 A g−1, Ge/Zn2GeO4NFs delivered a high capacity of 1621 mA h g−1 with an initial coulombic efficiency of 62%, and even after the 200th cycle a capacity of 816 mA h g−1 could be maintained. Further, the Ge/Zn2GeO4NFs anode delivered excellent rate capabilities of 567 and 388 mA h g−1 at high current densities of 2 and 5 A g−1, which were superior to the micron-sized Ge electrode (133 mA h g−1 at 5 A g−1). The results show that the Zn2GeO4 nanoflower, which adheres on the micron Ge substrate inseparably, could buffer the volume change of Ge, enlarge the electrolyte contact area, provide continuous lithium-ion and electron pathways, and thus improve the lithium-storage performance of the micron-sized Ge electrodes. This synthesis strategy provides new ideas for the development of micron-sized anode materials for LIBs.
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
DYES AND PIGMENTS
·
2018
·
IF 3.767
Yuchi Zhang,Hanzhi Yao,Yan Xu,Zhiguo Xia
Engineering novel ratiometric temperature sensors with high temperature sensitivity is still of a great challenge in versatile temperature measurement fields. Herein, a self-calibrated optical luminescent thermometer based on Eu 3+ /Mn 2+ dual-activator was fabricated in the same nanocomposite system, which integrated the photoluminescence originated from the temperature-insensitive Eu-metal organic framework with weak coupling effect and the temperature-sensitive Zn 2 GeO 4 :Mn 2+ with strong coupling effect. Specifically, the as-prepared nanocomposites composed of lanthanide MOF Eu-BTC (BTC = 1,3,5-benzenetricarboxylic acid) and Zn 2 GeO 4 :Mn 2+ nanorods possessed Eu 3+ /Mn 2+ dual red/green emission, which displays excellent ratiometric temperature-sensing functions and also has high relative sensitivity ( S r ) of 4.1% ºC −1 when they are used as ratiometric luminescent thermometer in the physiological temperatures (25–45 °C). These results demonstrate that such a design strategy with synergistic weak/strong coupling luminescence is useful and the as-obtained Eu-MOF/Zn 2 GeO 4 :Mn 2+ nanocomposites can be potential for temperature sensor applications.
研究领域:
材料科学
·
光学工程
·
生物医学工程
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产品关联
DOI
高影响因子
Energy Technology
·
2017
·Vol. 5
·期 9
·1656-1662
·
IF 2.789
Yifan Chen,Yangfan Lin,Ning Du,Chengmao Xiao,Shali Wu,Yaguang Zhang,Deren Yang
We report the synthesis of Zn 2 GeO 4 nanorods using a simple hydrothermal process. After the coating of a carbon layer by the thermal decomposition of acetylene gas, the Zn 2 GeO 4 @C core–shell nanorods were obtained. The as-synthesized Zn 2 GeO 4 @C core–shell nanorods were used as anode materials of lithium-ion batteries, which showed good cycling and rate performance. A highly reversible specific capacity of 718 mAh g −1 after 400 cycles was achieved at a current density of 400 mA g −1 . The core–shell nanostructures and partially amorphous and porous nanostructures helped to alleviate the volume change and enhance the conductivity during the charge/discharge process, which may be responsible for the good performance.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2021
·
IF 3.626
Qiaoqi Li,Fei Wang,Xin Zhou,Jianmei Chen,Chao Tang,Lili Zhang
Herein, we reported the systematic investigation of synergistic photo-thermal-catalysis for NaBH 4 hydrolysis reaction based on zinc orthogermanate. A series of Zn 2 GeO 4 : x Fe 3+ ( x = 0 to 0.10) catalysts were prepared via solvothermal method. The H 2 evolution experiments demonstrated that the photogenerated holes trap OH − not only shifted the equilibrium of NaBH 4 hydrolysis reaction toward the direction of H 2 evolution, but also inhibited the recombination of photogenerated carriers. With the remarkable photo-thermal synergism for the as-prepared catalysts, the H 2 evolution rate in photo-thermal-driven condition had witnessed several times higher than that in mono-energy driven condition. The catalysts remained stable after circulation tests.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Peng Liu,Qiang Ru,Peiming Zheng,Zhenglu Shi,Yang Liu,Chiquan Su,Xianhua Hou,Shichen Su,Francis Chi-Chung Ling
Currently, there are three primary obstacles to the development of high-performance supercapacitors: low electron conductivity of the electrode materials used, their poor ion-transport efficiency, and the unstable structure. Herein, to overcome these obstacles, one-dimensional Zn 2 GeO 4 (ZGO) rods were grown within a carbon nanotube (CNT) framework using a simple one-step hydrothermal strategy for use as a supercapacitor electrode material. The crosslinked ZGO/CNT-O hybrid exhibits a large contact surface area with respect to electrolytes, contains abundant electrochemical active sites, and has short ion-diffusion paths. Further, the flexible CNTs act as superior connective bridges, promoting electron transmission and resulting in a stable structure. The ZGO/CNT-O hybrid showed a specific capacitance of 164.25 F/g at a current density of 1 A/g. It also displayed superior cycling durability, exhibiting a specific capacity of 120 F/g at a current density of 10 A/g, even after 200,000 cycles. A simple crosslinking strategy and prolonged cycle durability are demonstrated, which endow ZGO/CNT-O with potential for use in supercapacitor electrodes.
研究领域:
材料科学
·
储能
·
纳米技术
·
电化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 36
·16000-16007
·
IF 2.7
Yao-Xing Han,Renagul Abdurahman,Yue Zhang,Shi-Ji Liu,Xiu-Zhen Yang,Xuan-He Guo,Rui Zhang,Xing-Hong Pan,Xue-Bo Yin
Copper in vegetables can enter the human body, and excessive copper may cause uncomfortable symptoms; thus, it is urgent to test copper ions for safety concerns. Herein, we prepared Zn2GeO4:Mn2+,In3+ (ZGO:Mn,In) persistent luminescent nanoparticles (PLNPs) and then grafted glutathione for the determination of copper ions. ZGO:Mn,In was prepared by doping In3+ in ZGO:Mn to improve the emission at 532 nm under excitation at 258 nm. The doping amount, temperature, time, and pH were carefully optimized for a stronger emission intensity than ZGO:Mn. The fractional densities and energy band gaps were calculated by density functional theory, revealing the excitation enhancement mechanism of ZGO:Mn,In. The surface of ZGO:Mn,In was modified with carboxyl groups for linking glutathione to specially identify Cu2+ ions. The identification resulted in the aggregation-induced quenching of PLNPs’ emission. Thus, the sensor exhibited good selectivity for copper ions, and the composite was successfully applied to the detection of copper ions in serum and vegetable samples.
研究领域:
材料科学
·
生物医学工程
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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）