NANOTECHNOLOGY
·
2021
·Vol. 32
·期 19
·195708
·
IF 3.874
Xuewen Xia,Junqi Li,Chaoyi Chen,Yuan-Pei Lan,Xisong Mao,Fusheng Bai
Morphological tuning or additional cation doping is one of the potential and simple methods to enhance the photocatalytic properties of ceria, in which rare-earth element doped ceria nanorods (CeO2-RE NRs) are expected to be a promising photocatalyst with high activity. But the optimal doping conditions, including the variety and concentration of RE elements are ambiguous, and the contribution of doped RE ions to the enhancement of photocatalytic activity needs to be further studied. In this work, we doped La, Y and Sm with a wide range of 0%–30% into CeO2 NRs, and investigated the phase, morphology, band gap, oxygen vacancy concentration, PL spectra and photocatalytic activity variation under different doping conditions. All synthesized CeO2-RE NRs possessed a good nanorod morphology except the 15 and 30% Y-doped samples. The energy band gaps of the synthesized samples changed slightly; the 10% CeO2-RE NRs with the narrowest band gaps possessed the higher photocatalytic performance. The most outstanding photocatalyst was found to be the 10% Y-doped CeO2 NRs with a methylene blue photodegradation ratio of 85.59% and rate constant of 0.0134 min−1, which is particularly associated with a significant higher oxygen vacancy concentration and obviously lower recombination rate of photogenerated e−/h+ pairs. The doped RE ions and the promotion of oxygen vacancy generation impede the recombination of photogenerated carriers, which is proposed as the main reason to enhance the photocatalytic property of CeO2.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Hang Zhang,Hang Yang,Guogang Li,Shiqi Liu,Haoran Li,Yuming Gong,Yujun Liang,Yongjun Chen
Currently, phosphor materials play an important role in designing noncontact remote optical thermometers. Although many approaches have contributed to improve thermometric performance of optical thermometers including optimization of host materials, size of nanoparticles , dopant type and concentration as well as excitation density and phonon energy engineering, the development of highly sensitive optical thermometric materials is still a challenge. Hence, we developed novel CaNb 2 O 6 (CNO):Ln 3+ (Ln 3+ = Eu 3+ /Sm 3+ /Dy 3+ /Tb 3+ ) phosphors as highly thermometric materials and proposed a novel strategy for further enhancing its thermometric performance via adding the intensity of indicator signal by co-doping Bi 3+ ions in current phosphor system. Typically, the as-prepared CNO:Ln 3+ phosphors present a broad blue emission around 470 nm originated from NbO 6 octahedral groups and some respective emission lines derived from the characteristic f-f transitions of Ln 3+ ions. Based on the diverse thermal quenching performance between blue emission and Ln 3+ ions emission , the temperature sensitivities of CNO:Ln 3+ were investigated in detail. Among them, the maximum relative sensitivity of CNO:Eu 3+ sample reached 1.991% K −1 in the range of 298–448 K and remained 97% after five temperature cycles. Furthermore, an obvious discoloration was discovered during temperature cycle testing in CNO:Ln 3+ samples under 254 nm UV lamp. Through doping Bi 3+ ion, the strongest intensity of indicator signal is 24 folds that of CNO host. Correspondingly, the relative sensitivity of CNO:Bi 3+ , Eu 3+ sample is obviously improved to 3.793% K −1 in the range of 298–523 K, owing to a larger range of the FIR value and a wider drop range of indicator signal. This work opens up an effective pathway to improving thermometric performance of optical thermometers by enhancing the intensity of indicator signal of employed phosphor materials.
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 ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Guang-Xin Xiang,Guo-Jun Wang,Zhi-Jun Zhang,He Feng,Jing-Tai Zhao,Jiao Wang,Xin-Yuan Sun,Ri-Hua Mao,Yong Wang
The uniform 1D nano-rods of RE 3+ doped Ln 7 O 6 F 9 ( Ln = Y and Lu; RE = Pr, Sm and Eu) were synthesized through a facile two-step hydrothermal method without extra fluorine source followed by post-heat treatment. The phase formation, morphologies, as well as photoluminescence properties of the materials were investigated. The precursor composition was determined to be Ln (OH) 1.69 F 1.31 using the Fourier transform infrared spectrum (FT-IR), thermal gravimetric and differential scanning calorimetry (TG-DSC). The average lengths of Y 7 O 6 F 9 and Lu 7 O 6 F 9 were about 6.8 and 7.9 μm, respectively, with the average width of about 650 nm. It was interesting that the tip of the nano-rods exhibits a straight line and divergent umbrella shaped bifurcation for Y 7 O 6 F 9 and Lu 7 O 6 F 9 , respectively. Upon ultraviolet excitation, Pr 3+ , Sm 3+ and Eu 3+ ions in Ln 7 O 6 F 9 showed blue, orange and red emissions originating from their characteristic f-f transitions. In addition, the 4 f 1 5 d 1 → 4 f 2 band emissions (340–450 nm) as well as typical 4 f 2 → 4 f 2 line emissions (450–700 nm) of Pr 3+ were observed in Pr 3+ -doped Ln 7 O 6 F 9 . For Sm 3+ -doped Ln 7 O 6 F 9 , only the typical f - f transitions of Sm 3+ were observed with the absence of charge transfer (CT) band. However, the broad excitation bands at 255 nm attributing to the charge transfer transition of Eu 3+ (i.e. O 2− → Eu 3+ CT) were observed in Eu 3+ -doped Ln 7 O 6 F 9 .
研究领域:
材料科学
·
纳米技术
·
光学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2012
·
IF 4.601
Wenlong Yin,Kai Feng,Wendong Wang,Youguo Shi,Wenyu Hao,Jiyong Yao,Yicheng Wu
The twelve quaternary rare-earth selenides Ba2MLnSe5 (M = Ga, In; Ln = Y, Nd, Sm, Gd, Dy, Er) have been synthesized for the first time. The compounds Ba2GaLnSe5 (Ln = Y, Nd, Sm, Gd, Dy, Er) are isostructural and crystallize in a new structure type in the centrosymmetric space group P1̅ of the triclinic system while the isostructural compounds Ba2InLnSe5 (Ln = Y, Nd, Sm, Gd, Dy, Er) belong to the Ba2BiInS5 structure type and crystallize in the noncentrosymmetric space group Cmc21 of the orthorhombic system. The structures contain infinite one-dimensional anionic chains 1∞[GaLnSe5]4– and 1∞[InLnSe5]4–, and both chains are built from LnSe6 octahedra and MSe4 (M = Ga, In) tetrahedra in the corresponding selenides. As deduced from the diffuse reflectance spectra, the band gaps of most Ba2MLnSe5 (M = Ga, In; Ln = Y, Nd, Sm, Gd, Dy, Er) compounds are around 2.2 eV. The magnetic susceptibility measurements on Ba2GaGdSe5 and Ba2InLnSe5 (Ln = Nd, Gd, Dy, Er) indicate that they are paramagnetic and obey the Curie–Weiss law, while the magnetic susceptibility of Ba2InSmSe5 deviates from the Curie–Weiss law as a result of the crystal field splitting. Furthermore, Ba2InYSe5 exhibits a strong second harmonic generation response close to that of AgGaSe2, when probed with the 2090 nm laser as fundamental wavelength.
研究领域:
材料科学
·
固体化学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Yingjie Zhou,Feifan Wei,Haihua Wu
Electrocatalytic CO 2 reduction in solid oxide electrolysis cells (SOECs) can simultaneously convert CO 2 to valuable chemicals or fuels by integrating with renewable energy so as to alleviate the greenhouse effects and energy crisis. Cerium oxide (CeO 2 ) with high redox stability and catalytic activity toward CO 2 reduction is considered a promising SOEC cathode. However, CeO 2 is rarely directly employed as cathodes due to its unsatisfactory electrical properties. Suitable modification of CeO 2 becomes essential to improve its electrocatalytic activity . Herein, Fe-decorated on Sm-doped CeO 2 via a simple mechanical milling process was employed as cathodes for high-temperature CO 2 electrolysis in SOEC. The addition of Fe species on Sm-doped CeO 2 can greatly enhance the CO 2 electrolysis efficiency, mainly attributing to the increased catalytic active sites, electronic pairs, and oxygen vacancy concentrations, which facilitated the CO 2 adsorption and dissociation as well as the electron-ion transportation. The 1.0 wt.% Fe-decoreated on Sm-doped CeO 2 showed the highest current density of 0.57 A cm −2 at 1.9 V under 800 °C. Moreover, the co-existence of doped and surface coated Fe species on Sm-doped CeO 2 with moderate oxygen vacancies and adequate electronic transportation paths facilitate the high-temperature CO 2 electrolysis.
研究领域:
材料科学
·
能源化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 18
·11534-11542
·
IF 4.036
Bohan Wang,Zhihao Wang,Peng Mao,Yu Wang
Conventional luminescent materials generally exhibit uni-color and transient emission under UV excitation, which makes them mediocre in the field of anti-counterfeiting. The high-level anti-counterfeiting techniques are always becoming more complicated and in need of multi-color and persistent luminescent materials. Herein, we report a series of β-NaYF4:RE3+ (RE = Sm, Tb, Dy, Pr) persistent luminescent phosphors with multi-color emitting and ultra-long persistent luminescence under the irradiation of X-rays. The effects of doping concentrations of RE3+ on the size, morphology, radioluminescence and afterglow performance of the products are investigated in detail. Hexagonal structured rod-like β-NaYF4:Tb3+ crystals show super strong X-ray response and the afterglow signal lasts for up to seven days after X-rays are turned off. Upon X-rays irradiation, some of the F− ions are expected to escape from the crystal lattice by elastic collisions, leading to the generation of Frenkel defects: the F vacancies and interstitials , which capture electrons and release them slowly to achieve different afterglow emission times. Taking advantages of the extraordinary radioluminescence performance of the β-NaYF4:RE3+ persistent luminescent phosphors, the dynamic anti-counterfeiting patterns that containing rich time-resolved information were successfully designed.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Jian Wu,Ying Zhang,Min Luo,Bing Lu,Yan Yang,Kai Sun,Daming Chen,Yingli Liu,Jie Li
Co 2 Z ferrite with superior performance is a beneficial material for high filter devices and antenna substrates. In this work, Ba 3 Co 2 Fe 24-x Sm x O 41 ( x = 0.00–0.50 with a step of 0.10) materials were prepared using low temperature-fired process with 2.5 wt% of Bi 2 O 3 . The phase formation, microstructure, magnetic property , complex permittivity, and complex permeability were studied using X-ray diffraction, scanning electron microscopy, vibrating sample magnetometer , and vector network analyzer. The materials remained in a single hexagonal phase, and the grain size increased with increase of Sm-doped content. Saturation magnetization of samples increased at first and then decreased. When x = 0.20 and 0.30, the value of 4π M S was 2910.4 G and 2861.7 G, respectively. The variation of saturation magnetization is mainly due to the occupancy of Sm 3+ ions. When Sm 3+ ion doped Fe 3+ ion of Co 2 Z ferrite, Sm 3+ ion first preferred to occupy 4e IV site due to its low electronegativity, and then occupied 12k and 4f sites at high doped content, affecting magnetic moment and magneto-crystalline anisotropy. Furthermore, low-temperature sintering improves magnetic-dielectric properties of Sm-doped materials in high-frequency range. The real part of magnetic permeability (μ′) reached a maximum value of 8.4 when x = 0.20 and the real part of dielectric permittivity (ε′) reached a maximum value of 14.1 when x = 0.30. The magnetic loss and dielectric loss remained low (tanδ μ = 0.05–0.08 and tanδ ε = 0.005–0.04) and the off-cut frequency was nearly 1 GHz. The results indicated that these magnetic-dielectric materials have great potential for high-frequency antenna applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2022
·Vol. 12
·期 11
·1608
·
IF 2.67
Zijun Ye,Yu Jiang,Minmin Mao,Zhiyu Xiu,Mengjiao Chi,Guofa Wu,Bing Liu,Dawei Wang,Bin Yang,Kaixin Song
In this work, Y2.95R0.05MgAl3SiO12(R = Yb, Y, Dy, Eu, Sm) microwave single-phase dielectric ceramics were successfully prepared via a conventional ceramic sintering technology by doping a series of rare earth elements (Yb, Y, Dy, Eu, Sm) with different ionic radii for the first time. The effects of A-sites occupied by rare earth elements on the microwave dielectric properties of Y2.95R0.05MgAl3SiO12were studied using crystal structure refinement, a scanning electron microscope (SEM), bond valence theory, P-V-L theory, and infrared reflection spectroscopy. It was found that the ionicity of the Y-O bond, the lattice energy, the bond energy, and the bond valance of the Al(Tet)-O bond had important effects on the microwave dielectric properties. Particularly, the optimum microwave dielectric properties,εr= 9.68,Q×f= 68,866 GHz, andτf= −35.8 ppm/°C, were obtained for Y2.95Dy0.05MgAl3SiO12when sintered at 1575 °C for 6 h, displaying its potential for 5G communication.Keywords:garnet;microwave dielectric properties;P–V–L theory;infrared reflection spectroscopy
研究领域:
材料科学
·
通信工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Weichen Xu,Xiaomeng Li,Hong Wang,Fuliang Wang,Shouqiang Han,Jing Guo
Microwave dielectric ceramics are critical components in wireless communications. However, it is still a challenge to develop microwave dielectric ceramics with reduced sintering temperatures, high thermal stabilities and good dielectric properties at the same time. Herein, the entropy value, which is able to modulate the grain boundary energy and adjust the inherent sintering temperature, is engineered to develop high-performance microwave dielectric ceramics with low sintering temperatures. The structure-property relationships of AWO 4 ceramics, including (NaCaBi) 1/3 WO 4 , (NaCaSrBi) 1/4 WO 4 , (NaLiCaBiSm) 1/5 WO 4 and (NaLiCaSrBiSm) 1/6 WO 4 with increased entropy values are investigated systematically. X-ray diffraction and high-resolution TEM analyses confirm the formation of single-phase solid solutions with the tetragonal scheelite structure in AWO 4 ceramics. As the number of elements in the A-site varies, the relative permittivities, Q × f values and TCF values shift in the range of 12.2–16.5, 8,000–25,000 GHz and −32.3–31.6 ppm/°C, respectively. Simultaneously, the high-entropy samples demonstrate the lowest sintering temperature of 750 °C among the four formulations. Phillips-Van Vechten-Levine (PVL) complex chemical bond theory reveals that the covalency, lattice energy and bond energy affect the relative permittivity, Q × f value and TCF value, respectively. Raman spectra suggest that high entropy value leads to increased disorder, and infrared reflectivity spectra illustrate that the dielectric response is dominated by polarized optical phonons of [WO 4 ] tetrahedron. It is anticipated that entropy design will facilitate the development of microwave dielectric ceramics in low temperature co-fired ceramic applications.
研究领域:
材料科学
·
陶瓷
·
介电材料
·
电子材料
·
固态化学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2022
·Vol. 12
·期 7
·963
·
IF 2.67
Weili Wang,Shihai Miao,Dongxun Chen,Yanjie Liang
Trivalent lanthanides (Ln3+) doped bismuth-based inorganic compounds have attracted considerable interest as promising candidates for next-generation inorganic luminescent materials. Here, a series of K0.3Bi0.7F2.4(KBF) nanocrystalline particles with controlled morphology have been synthesized through a low-temperature aqueous-phase precipitation method. Using KBF as the host matrix, Eu3+, Tb3+, Pr3+, Nd3+, Sm3+,and Dy3+ions are introduced to obtain K0.3Bi0.7F2.4:Ln3+(KBF:Ln) nanophosphors. The as-prepared KBF:Ln nanophosphors exhibit commendable photoluminescence properties, in which multicolor emissions in a single host lattice can be obtained by doping different Ln3+ions when excited by ultraviolet light. Moreover, the morphology and photoluminescence performance of these nanophosphors remain unchanged under different soaking times in water, showing good stability in a humid environment. The proposed simple and rapid synthesis route, low-cost and nontoxic bismuth-based host matrix, and tunable luminescent colors will lead the way to access these KBF:Ln nanophosphors for appealing applications such as white LEDs and optical thermometry.
研究领域:
材料科学
·
纳米技术
·
光学
·
化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Jinpeng Zhao,Zi'ang Liu,Suo Fu,Fazheng Wei,Xiaowei Chen,Danqing Liu,Weicheng Huang,Shaoqin Liu
A Sm/Co dual-doping strategy is introduced to the A and B sites of BiFeO 3 (BFO) perovskite structure to boost the synergetic piezo-photocatalytic performance for organic pollutant degradation and hydrogen production. The optimized doping ratio enables it to achieve the best balance between carrier concentration and piezoelectric response while regulating the energy band. The dual-doped sample Bi 0.9 Sm 0.1 Fe 0.8 Co 0.2 O 3 (BS 0.1 FC 0.2 O) exhibits the best piezo-photocatalytic performance, achieving a 90% RhB degradation efficiency in 60 min and hydrogen production rate of 1525 μmol g −1 h −1 . The coupling of Sm and Co co-doping in BFO effectively enhances the light harvesting and the piezoelectric polarization performance, which facilitate the generation and separation of electrons and holes. This work provides a paradigm for designing efficient piezo-photocatalysts with tailored band structures through bimetal co-doping strategies and demonstrates great potential for applications in environmental remediation and hydrogen production.
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Chaochao Tao,Songsong Ding,Shengqian Wang,Lin Liu,Houfa Mao,Genyuan Chen,Hualan Xu,Chongfeng Guo,Shengliang Zhong
Multicolor emission has long been a critical scientific challenge in the field of persistent luminescence (PersL) materials, with the achievement of multicolor PersL emission within a single host matrix representing a primary research objective. Herein, a new and effective method of using coordination polymers (CPs) as precursors is designed to synthesize multicolored CdSiO 3 :RE 3+ (RE = Pr, Sm, Eu, Tb, Tm) PersL materials. Through variation of rare earth dopants, we successfully achieved color-tunable PersL emission spanning brown, pink, purple, red, green, and blue spectra. The influence of RE 3+ dopants on the crystal structure, morphology and optical properties are studied in detail. Notably, this straightforward synthesis strategy enabled the effective production of nanospherical particles exhibiting regular morphology and uniform size distribution. The electronic band structure of the material was theoretically analyzed using density functional theory (DFT) calculations. Combined with thermoluminescence (TL) measurements were performed to elucidate the underlying PersL mechanism. To demonstrate practical applications, we designed a dynamic anti-counterfeiting pattern and evaluated the potential utility of CdSiO 3 :RE 3+ materials. This study not only enhances our fundamental understanding of CdSiO 3 -based PersL materials, but also provides novel insights into morphology and size control strategies that could be extended to other PersL material systems.
研究领域:
材料科学
·
光学
✓ 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）