Energies
·
2022
·Vol. 15
·期 22
·8542
·
IF 3.252
Yue Zhang,Ruixing Li
Nanoscale tungsten bronze can convert near-infrared light into thermal energy. For a chemical synthesis, intermediate products and processes are potentially positive or negative to an end product. In this study, (NH4)2SO4was added into the hydrothermal system of WO3, CsCl, CH3CH2CHO, and NH3·H2O to increase the Cs/W ratio in solution. An intermediate, Cs1.1W1.65O5.5, was isolated. Subsequently, it was confirmed via a kinetics experiment conducted for different times. The results of the NH3·H2O and NH4COOCH3system indicate there are two influence factors that influence the formation of Cs1.1W1.65O5.5: the leaching out of W and imine reactions. A low leaching out rate induces a high Cs/W ratio and low-concentration W in solution, leading to the formation of Cs1.1W1.65O5.5. The imine reaction decreasing CH3CH2CHO restrains the reduction in Cs1.1W1.65O5.5. The increase in CH3CH2COO−with the reduction reaction results in both the micron-size sticks and nano-size equiaxial particles in powder.Keywords:cesium tungsten bronze;intermediate;hydrothermal;synthesis;near-infrared response
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2014
·
IF 2.269
T. Wei,Y.Q. Wang,C.Z. Zhao,X.X. Dong,J.H. Wang
Filled tetragonal tungsten bronze (TTB) structure Sr 4 La 2 Ti 4 Nb 6 O 30 co-doped by Er 3+ and Yb 3+ (SLTN: x Er 3+ – y Yb 3+ ) ceramics with different x and y were synthesized, and their crystal structure, upconversion photoluminescence (UC-PL), and dielectric permittivity were investigated for the first time. Under 980 nm infrared (IR) excitation, bright single-band UC green (515–570 nm) emission was observed for SLTN: x Er 3+ – y Yb 3+ ( x =0.05, y =0), however, featured two-bands UC emission (515–570 nm and 640–690 nm) was confirmed for all SLTN: x Er 3+ – y Yb 3+ ( x =0.05, y ≠0) samples. Two-photon energy transfer process was proved through pumping laser power dependence of emission intensity measurement. It is believed that energy back transfer (EBT) process should be mainly responsible for the two-bands UC emission. In addition, the dielectric properties were also discussed for SLTN: x Er 3+ – y Yb 3+ system.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 20
·24939-24952
·
IF 2.478
Guo Xiaoying,Zhang Weifeng,Wu Shan,Sun Chaozhong,Hu Changzheng,Liu Laijun,Fang Liang,Luo Nengneng
In this study, Ba 4 RCo 0.5 Nb 9.5 O 30 (R = La, Nd, Sm, Eu) (BRCN) ceramics were synthesized using a high-temperature solid-state reaction. The XRD refinement results show that ceramic samples are tetragonal tungsten bronze (TTB). As the radius of rare-earth ions decreases, the unit cell volume of BRCN ceramics decreases, and the radius difference between Ba 2+ and R ions increase, which results in BO 6 octahedral distortion and the Raman peaks shift to high frequency. In addition, as the radius of rare-earth ions decreases, the ionic displacements increase and thus the dielectric constant peak temperature goes up. The high-temperature impedance results show that there exists n-type electronic conduction in the samples. The remanent polarization of the P–E curve at low frequencies increases from 0.470 to 1.038 μC cm −2 as the rare-earth ion radius decreases.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Luomeng Chao,Changwei Sun,Jiaxin Li,Miao Sun,Jia Liu,Yonghong Ma
Although the optical properties of nanocrystalline cesium tungsten bronze have been widely studied, there is a lack of research on the effect of particle size on its optical properties. In order to further investigate size and shape effect on the NIR shielding performance, cesium tungsten bronze nanoparticles with different sizes and morphologies were prepared by two methods. The size of irregular shaped samples prepared by solvothermal method is tens of nanometers, while the size of hexagonal prism shaped samples prepared by solid state reaction method is hundreds of nanometers. The element spectrums shows that there are more oxygen vacancies in large particles than in small particles. The NIR shielding performance of large particles far lower than that of small particles, indicating that the influence of shape and size on optical properties is more obvious than that of oxygen vacancy. Theoretical calculation on hexagonal prism shaped particles exhibits that the NIR extinction of large aspect ratio is better at longer wavelength and small aspect ratio is better at shorter wavelength.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Jian Guo,Zhiming Geng,Lanji Wen,Ningchong Zheng,Mingqian Yuan,Ke Wang,Shan-Tao Zhang
In conventional knowledge, ferroelectric solid solutions were formed between members belonging to the same crystal structure family. Since both tungsten bronze and perovskite structures are constructed by connecting the corner-sharing oxygen octahedra, it offers a possibility for formatting an unusual solid solution between these two families. Herein, (1 – x)Sr0.6Ba0.4Nb2O6-xBaTiO3, (1 – x)SBN-xBT, solid solutions were synthesized and the solution mechanism was resolved from a structure viewpoint. With increasing BT content, the solid solution persists of tetragonal tungsten bronze structure, but the lattice parameter a (= b) decreases whereas c increases, resulting in the significant reduction of grains anisotropy. The ferroelectric–relaxor phase transition temperature shows a monotonic increase as x increases. However, the ferroelectricity evolution is not monotonous as a function of BT content because of the competitive effects of Ba and Ti on the property. As a result, the x = 0.10 ceramic shows the strongest ferroelectricity and a remarkable electrocaloric effect of 1.4 K near room temperature. This work challenges the traditional view of solid solution formation and provides an alternative way to modulate the structure and properties of ferroelectrics.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Chaozhong Sun,Xiaoying Guo,Rui Ji,Changzheng Hu,Laijun Liu,Liang Fang,Zhenxiang Cheng,Nengneng Luo
The triboelectric effect has recently demonstrated its great potential in environmental remediation and even new energy applications for triggering a number of catalytic reactions by utilizing trivial mechanical energy. In this study, Ba 4 Nd 2 Fe 2 Nb 8 O 30 (BNFN) submicron powders were used to degrade organic dyes via the tribocatalytic effect. Under the frictional excitation of three PTFE stirring rods in a 5 mg/L RhB dye solution, BNFN demonstrates a high tribocatalytic degradation efficiency of 97% in 2 h. Hydroxyl radicals (•OH) and superoxide radicals (•O 2 －) were also detected during the catalysis process, which proves that triboelectric energy stimulates BNFN to generate electron-hole pairs. The tribocatalysis of tungsten bronze BNFN submicron powders provides a novel and efficient method for the degradation of wastewater dye by utilizing trivial mechanical energy.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Materials Today Chemistry
·
2023
·
IF 7.3
Z. Jin,X. Zheng,Z. Zhu,C. Hu,L. Liu,L. Fang,N. Luo,Z. Cheng
It is urgently necessary to develop efficient and environmentally friendly catalysts to solve pollution problems faced by humankind. In this work, ferroelectric Ba 2-x Sr 3+x LaNb 7 Ti 3 O 30 (x = 0, 0.2, 0.4, 0.6) (BSLNT) tungsten bronze ceramics were prepared using a high-temperature solid-phase method and applied as tribocatalysts for degradation of organics. The built-in electric field in ferroelectric BSLNT was enhanced by modulating the ferroelectric polarization and by electrical poling. The degradation results show that better ferroelectric properties of the tribocatalysts led to better the catalytic capability with 92% RhB degradation after 2 h. The further enhanced polarization of the catalyst by electrical poling can improve the degradation efficiency of RhB to 96.8% in 2 h. Under the synergistic effect of illumination and friction, the degradation efficiency of RhB after 30 min reached 95.2%. Therefore, a highly efficient ferroelectric tribocatalyst with an enhanced built-in electric field for degradation of dye wastewater was demonstrated, expanding the application of ferroelectric materials in the catalysis field.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 22
·13386-13395
·
IF 3.361
Chaozhong Sun,Xiaoying Guo,Changzheng Hu,Laijun Liu,Liang Fang,Zhenxiang Cheng,Nengneng Luo
Searching for a new approach in environmental remediation in terms of dye degradation is important in industrialized society. In this work, ferroelectric Ba2.5Sr2.5Nb8Ta2O30 (BSNT) submicron powders prepared by the high-temperature solid-phase method are used for dye degradation under magnetic stirring. The dye in solution can be quickly degraded by magnetically stirring BSNT submicron particles in the dark in ambient temperature conditions. More importantly, the degradation efficiency can be greatly improved through simple modification of the stirring materials from glass to polypropylene, with a degradation efficiency of rhodamine B as high as 99% in 1.5 h at a gentle stirring speed of 300 rpm. Control experiments reveal that the degradation of the dye is mainly contributed by the friction between BSNT submicron particles and PTFE stirring rods. It is proposed that the friction between ferroelectric polar BSNT particles and PTFE causes charge transfer and induces a non-zero internal electric field to drive the separation of electron–hole pairs in BSNT particles, resulting in a novel tribocatalytic degradation of the dye, which is proven by the detection of ˙OH and ˙O2− intermediate products during stirring. This work demonstrates that the friction energy of ferroelectric materials with strong polarization is an alternative approach for highly efficient dye degradation.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Nanoscale
·
2024
·
IF 5.8
Zhihong Zhu,Zuheng Jin,Chuan Jiang,Sha Wu,Changzheng Hu,Laijun Liu,Liang Fang,Z. X. Cheng
Tribocatalysis is a method that converts mechanical energy into chemical energy. In this study, we synthesized tungsten bronze structure Ba0.75Sr0.25Nb1.9Ta0.1O6 ferroelectric ceramic submicron powder using a traditional solid-state route, and the powder exhibits excellent performance in tribocatalysis water splitting for hydrogen. Under the friction stirring of three polytetrafluoroethylene (PTFE) magnetic stir bars in pure water, the rate of hydrogen generation by Ba0.75Sr0.25Nb1.9Ta0.1O6 ferroelectric submicron powder is 200 μmol/h/g, and after 72 hours, the accumulated hydrogen production reaches 15892.8 μmol/g. Additionally, this ferroelectric tungsten bronze ferroelectric material also exhibits excellent tribocatalysis degradation ability toward RhB dyes, with degradation efficiency reaching 96% in 2 hours. The work of tribocatalysis based on tungsten bronze ferroelectric materials represents a significant step forward in versatile energy utilization for clean energy and environmental wastewater degradation.
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2021
·
IF 8.067
Guang Yang,Yunhang Qi,Daming Hu,Haochen Wang,Hongfei Chen,Liangmiao Zhang,Chuanxiang Cao,Bin Liu,Fang Xia,Yanfeng Gao
Tungsten bronze coatings and films have attracted global attention for their applications in near-infrared (NIR)-shielding windows. However, they are unstable in strong ultraviolet, humid heat, alkaline and/or oxidizing environments and are difficult to be coated on glass surfaces with complex shape. Here, we address these limitations by doping sodium tungsten bronze (Na x WO 3 ) into bulk glasses using a simple glass melting method. X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, TEM and SEM-EDS characterization confirmed the presence of sodium tungsten bronze (Na x WO 3 ) functional units inside the 34SiO 2 -38B 2 O 3 -28NaF glass matrix. Because the functional units are well protected by the glass matrix, the fabricated glasses are stable under hot, humid, oxidizing conditions, as well as under ambient conditions, with no change after 360 days. The NIR-shielding performance of these glasses can be adjusted to as high as 100 % by varying WO x concentration (2−8 mol%) and quenching temperature (1000−1400 °C). With a content of 6 mol% WO x and a quenching temperature of 1000 °C, the bulk glass shows 63 % transmission of visible light and only 11 % transmission of NIR light at 1100 nm. Thermal insulation experiments show that the NIR-shielding performance of the glasses are far superior to commercial soda lime window glass or indium-doped tin oxide (ITO) glass, and comparable to cesium tungsten bronze coated glass. The novel bulk glasses have higher stability, simpler processing, and can be easily made into complex shapes, making them excellent alternative materials for energy-saving glasses.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2020
·
IF 6.289
Guanghui Liu,Ju Xu,Ruixing Li
Recently, nano-cesium tungsten bronze (Cs x WO 3 ) is found to be a new candidate for the application in solar filter due to its high visible transmittance and excellent near-infrared shielding ability. However, a typical two-dimensional (2D) Cs x WO 3 has not been reported since 2D nanomaterials have attracted great attention due to their fascinating properties, e.g., graphene. Herein, a novel synthesis system and related mechanisms are tried to develop for synthesizing 2D Cs x WO 3 via hydrothermal method, which an original inspiration derived from the morphology control of sulfides. The results indicate that morphology modifier represents a new strategy in which thiourea and oleylamine interact synergistically rather than independently to synthesize 2D Cs 0.3 WO 3 . The more regular and larger the rectangular nanosheet, the broader and stronger the light absorption, the rectangular Cs 0.3 WO 3 nanosheets with the maximum size are synthesized from thiourea, oleylamine and HCl concentrations of 4, 0.061 and 320 mmol/L, respectively, and exhibit a broad and strong absorption spectrum. The above nanosheet shows excellent instantaneous photo-thermal conversion property resulting in an obvious temperature increases from 20 °C to 88.5 °C when it was irradiated by 50 W halogen lamp for 10 s. Finally, both chemical reaction and morphological evolution in the synthesis processes are revealed.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2014
·
IF 1.968
T. Wei,Y.Q. Wang,C.Z. Zhao,L.Q. Zhan
Unfilled tetragonal tungsten bronze (TTB) structure Ba 4 LaTiNb 9 O 30 doped by Eu 3+ (BLTN: Eu 3+ x ) with different x have been prepared, and their structural, photoluminescence, dielectric, and ferroelectric properties are carefully investigated in this work. Bright red emission, originating from 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 transitions of Eu 3+ ions, has been observed by naked eyes at room temperature under near ultraviolet (NUV) light excitation. Optimized emission intensity is obtained when x = 1.00 for present unfilled TTB-type BLTN: Eu 3+ x samples. Furthermore, with increasing x , the dielectric and ferroelectric characteristics of the unfilled TTB-type BLTN: Eu 3+ x samples also display remarkable variation. When x ≥ 0.50 relaxor-like ferroelectric phase transitions are detected above room temperature, it is believed that unfilled TTB-type BLTN: Eu 3+ x = 1.00 involving bright photoluminescence and enhanced ferroelectric properties may act as a potentially multifunctional optical-electro material.
研究领域:
材料科学
·
光学
·
电学
✓ 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）