TALANTA
·
2023
·
IF 6.1
Xiao Tian,Lei Zhao
Concentrations of trace elements in coal and coal combustion products are commonly analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) due to large number of elements detected and the relatively the low detection limits of this technique. Like other geological samples, complete dissolution of coal and coal combustion products is also essential for accurate ICP-MS results. In this study, Sr and Ba in coal and coal combustion products (fly and bottom ashes) from two coal-combustion power plants from North China analyzed by XRF and ICP-MS were comparatively studied. The concentrations of Sr and Ba analyzed by ICP-MS, when a mixture of acids (2 ml HF + 5 ml HNO 3 for each 50 mg coal sample and 5 ml HF + 2 ml HNO 3 for each 50 mg ash sample) was used for microwave-assisted digestion, do not fit well with the their relative XRF results. This is most probably due to the formation of the fluorides during microwave digestion, and this assumption is supported by the presence of various fluoride compounds, NaMgAl(F, OH) 6 ·H 2 O, NH 4 MgAlF 6 , AlF 3 , and K 2 SiF 6 , in the residues of all the coal and ash samples in our sequential extraction experiment. Cations of Sr and Ba were probably trapped into the divalent cation sites of the fluorides. Concentrations of Sr and Ba analyzed by ICP-MS using increased HF and HF/HNO 3 ratio (7 ml HF and 2 ml HNO 3 for each 50 mg coal/ash sample) are in better agreement with the XRF results. Our results indicate that excess amount of HF probably has led to the suppression of these elements due to fluoride precipitation. The results indicate that the modified digestion method is capable of achieving complete digestion of coal samples and results in a reliable analysis of Sr and Ba concentrations in coal samples and most fly ashes by ICP-MS. However, the formation of insoluble fluorides is probably not completely suppressed for some bottom ash samples, which can result in underestimation of Sr and Ba concentrations. Nevertheless, XRF analysis can serve as a reliable cross-check method to assist in the evaluation of the accuracy of ICP-MS results.
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高影响因子
CRYSTAL GROWTH & DESIGN
·
2024
·
IF 3.2
Pengju Xia,Yifeng Lei,Wanyuan Li,Kaiting Wu,Chengyu Ni,Man Xu,Wubin Dai
With the growing public awareness of protecting vision and prevention of hazardous effects, there is much-needed research on a “healthy” full visible spectrum under near-ultraviolet (nUV) excitation in phosphor-converted white light-emitting diodes (pc-wLEDs) to fill the “cyan gap” and avoid employing a blue LED chip. Herein, a novel series of borosilicates Ba2CaB2Si4O14 (BCBS): Ce3+/Tb3+/Sm3+/Sr2+/Na+ phosphors, presenting color-tunable photoluminescence (PL), high quantum yield (QY), and thermal stability, were designed and synthesized via a facile solid-phase reaction. The Rietveld analyses, density functional theory (DFT) simulations, and theoretical calculations of bond energy together imply the site occupations of Ce/Tb/Sm on Ba2+/Ca2+ sites with a preferred location on Ca2+ over the Ba2+ site. The broad/bright cyan-PL from BCBS: Ce under nUV excitation is associated with the allowed f–d transitions of Ce3+ and dual-site occupancies. The forbidden f–f transitions of both the green-PL of Tb and the red-PL of Sm were insensitive to the site environment and helpful to PL color regulation. The cascading Ce → Tb → Sm energy transfer is confirmed, where Tb is regarded as an energy transfer (ET) bridge to avoid the metal–metal charge transfer (MMCT) effect. The introduction of Na+ as both flux and charge compensator is for the sake of decreasing defects from heterovalent substitutions and regulating morphology. Further incorporation of Sr2+ is to modulate the lattice environments of dopants for controlling the shift of PL. Finally, as a proof-of-concept implement, a pc-wLED assembled by BCBS: Ce/Tb/Sm/Sr/Na and an nUV LED chip via a remote “capping” packaging strategy show attractive performance.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Ze Wei,Xueqing Xiong,Xiyong Chen,Juntao Pan,Donglin Cai,Xiaomei Huang,Gang Han,Yihui Liu,Zezuo Jiang,Toyohisa Fujita
The effects of Sr doping on the crystal structures, thermal expansion behaviors, defect chemistries , electrical and electrochemical properties of the perovskite materials, La 0.5 Gd 0.5 Ba 1− x Sr x Co 2 O 5+ δ (LGBCOSr- x, x =0–0.5), were systematically analyzed and discussed. The X-ray diffraction (XRD) investigation revealed that LGBCOSr- x undergoes a phase transformation from tetragonal ( x =0.1) to cubic ( x =0.5), and the materials exhibit good thermochemical compatibility with Ce 0.9 Gd 0.1 O 1.95 (GDC) under 1100 °C. Partial replacement of Ba with Sr is found helpful in decreasing the thermal expansivity of LGBCOSr- x and increasing the ability of oxygen vacancy formation in the materials. The latter could be attributed to the enhancement in the overall electrical conductivity and oxygen transport process in terms of low cathodic polarization resistance in LGBCOSr- x materials with high Sr doping content. Further analysis on the AC impedance spectroscopy assisted with the DRT (distribution of relaxation times) methodology suggested that the charge transfer sub-process is a predominant step in the oxygen transport processes across the LGBCOSr- x materials. These findings indicate that La 0.5 Gd 0.5 Ba 1− x Sr x Co 2 O 5+ δ is a promising cathode material for intermediate temperature solid oxide fuel cells.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 18
·1-16
·
IF 2.8
Yang Zaizhi,Shen Yalong,Zhu Yuan,Jiang Xiaoming,Liu Rui,Yang Zhen,Wang Shouliang,Xu Dong
Flash sintering has revolutionized the field of advanced ceramic preparation with the low heating temperature and extremely short sintering time. The difference of doped ions radius can influence the defect structure and resistivity of the sample through lattice distortion, subsequently altering the parameters and dielectric properties of flash sintering samples. By flash sintering technology, co-doped TiO 2 ceramics with the acceptor ions (Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ ) and donor ions (Nb 5+ ) were successfully prepared at 1100 °C for 24 min. According to the blackbody radiation model, Mg 2+ and Nb 5+ co-doped TiO 2 ceramics exhibit the highest surface temperature at the moment of flash sintering, approximately 1852 °C. Additionally, the co-doped TiO 2 ceramics with Ba 2+ and Nb 5+ ions exhibit the strongest polarization effect, with a dielectric constant above 10 5 . The acceptor ions with larger ions increase oxygen vacancies by enhancing the stability of defect complexes. The excellent giant dielectric properties are attributed to the combined action of the electron-pinned defect dipole effect and the internal barrier layer capacitor effect.
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CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Bowen Wang,Xuyan Xue,Changshuai Gong,Xuejiao Wang,Qiushi Wang,Ji-Guang Li
A series of Tb 3+ substituted layered perovskite Sr(La 1- x Tb x )AlO 4 ( x = 0–1) was synthesized via solid-state reaction. The influence of Tb 3+ on the phase, structure, photoluminescence, and long afterglow properties of the SrLaAlO 4 product was investigated. The fully substituted product SrTbAlO 4 was found to be isostructural with its SrLaAlO 4 counterpart, and the crystal structure parameters were first reported in this work. Photoluminescence investigation found that benefiting from the unique layered crystal structure, the activator Tb 3+ was well separated and the optimal doping concentration was found to be as high as 20 at%. Except for photoluminescence, the products simultaneously show long afterglow properties due to disorder cations distribution in the local structure and thus induced defect condition. When the UV light source is turned off, the afterglow luminescence of SrLaAlO 4 : 0.03 Tb 3+ can last over 1 h. The trap distribution of SrLaAlO 4 : Tb 3+ was analyzed in detail by thermoluminescence. The trap depth is calculated to be around 0.7–0.81 eV, the value of which highly coincides with the ideal energy level for trapping and releasing electrons at room temperature. On the basis of the experimental results, the mechanism of long afterglow luminescence of SrLaAlO 4 : Tb 3+ is elaborated and discussed.
研究领域:
材料科学
·
光学
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TALANTA
·
2022
·
IF 6.556
Heng Yan,Xuemei Liu,Fan Zhang,Kaiqiang Ma,Xuepeng Shao,Fengcheng Wu,Jun Han,Wenting Bu,Chuting Yang,Liangbin Li,Sheng Hu
U, Sr, Pb, Nd, and Hf isotope ratios can provide basic and important information of nuclear materials. We established a simple and efficient column chemistry method using nano-NaBiO 3, as both oxidizer and adsorbent, to completely separate Ce from rare earth elements (REEs). This new method exhibited a high decontamination (Ce/Nd < 10 −5 ) ability and was easy to conducted, thereby providing clear advantages compared to traditional liquid–liquid and solid phase micro-extraction techniques. Additionally, a rapid four-column separation procedure, based on Sr, TUR, Ln resins and nano-NaBiO 3 , was developed to isolate U, Sr, Pb, Nd, and Hf in ore samples. The entire procedure could be completed in 4–5 hrs. The robustness of the proposed method was demonstrated by analyzing the 235 U/ 238 U, 87 Sr/ 86 Sr, 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, 208 Pb/ 204 Pb, 142 Nd/ 144 Nd, 143 Nd/ 144 Nd, and 176 Hf/ 177 Hf isotopic ratios of two certified reference materials (CRMs). The analytical results obtained using this method showed good agreement with previously published data. The feasibility of this method was extended to the determination of isotope ratios in uranium ores . The results obtained from the two samples with different regions indicated that they have different isotopic ratios information. These findings indicate the potential for the use of this new method in nuclear forensic science.
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CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jianwei Dao,Zihao Han,Zhihao Jiang,Tiqun Wei,Junlin Xue,Bin Wang,Sicheng Yi,Liang Yang
Narrow-band red phosphors excited by near-ultraviolet light (n-UV) are significant for enhancing the R9 index and can produce high color rendering white LEDs. A range of KSr 1-x-y Ca y PO 4 :xEu 3+ red phosphors were synthesized by high-temperature solid-state reaction method. We investigated the effects of partially substituting Sr 2+ ions with Ca 2+ ions on the phosphors' crystal structure, photoluminescence and thermal stability. Significantly, incorporating Ca 2+ ions enhances the luminescent properties and thermal stability. Under n-UV light excitation, all samples exhibit red emission around 614 nm, corresponding to the 5 D 0 → 7 F 2 transition of Eu 3+ ions. At the doping concentration of Eu 3+ ions (x = 0.08), an optimal KSr 0.52 Ca 0.4 PO 4 :0.08Eu 3+ (y = 0.4) sample was obtained. The excitation wavelength exhibited a slight violet shift from 398 nm to 396 nm. At 150 °C, the luminescence intensity of KSr 0.92 PO 4 :0.08Eu 3+ remains 80.1 % of its value at room temperature, while that of KSr 0.52 Ca 0.4 PO 4 :0.08Eu 3+ reaches 89.7 %. White LED device can be fabricated by combining the as-prepared KSr 0.52 Ca 0.4 PO 4 :0.08Eu 3+ red phosphor with commercial BaMgAl 10 O 17 :Eu 2+ blue and (Ba, Sr) 2 SiO 4 :Eu 2+ green phosphors, along with encapsulation using n-UV LED chip (395–400 nm). The device emits bright white light and exhibits a high color rendering index (Ra = 87.6, R9 = 89.8) and suitable correlated color temperature (CCT = 5523 K) at 300 mA drive current. The results demonstrate that this work provides new application prospects for the fabrication of high color rendering white LEDs using n-UV light.
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Materials Today
·
2025
·
IF 22
Haiping Luo,Shenglan Zhou,Wenjie Deng,Jiahao Liu,Jiaqing Peng,Bo Li,Zhihua Xiong,Wei Wang,Xinyu Ye
Fe 3+ is a promising near-infrared (NIR) activator ion due to its tunable emission and non-toxicity, which has attracted growing interest. However, developing high-performance broadband NIR-emitting phosphors based on Fe 3+ remains a significant challenge. In this work, we present Fe 3+ -activated A 2 LuSbO 6 (A = Ba/Sr/Ca) double perovskite phosphors, which exhibit unusually long-wavelength NIR emission (>850 nm). By adopting a cation substitution strategy at the A-site, we designed the gradual replacement of large-radius ions with small-radius ions, achieving controllable tuning of emission from 847 nm to 937 nm. This substitution process simultaneously reduces structural symmetry and induces octahedral distortion, which breaks the spin-forbidden transition of Fe 3+ and enhances luminescence performance. However, the continuous emission redshift leads to a large Stokes shift, which suppresses Fe 3+ luminescence. The combined effect of these two factors results in optimal luminescence efficiency in Sr 2 LuSbO 6 :1.0 %Fe 3+ (SLSO) sample, with internal/external quantum efficiencies (IQE/EQE) of 94.8 %/54.5 %. To further enhance luminescence performance, we introduced the rare-earth Yb 3+ , establishing an efficient Fe 3+ →Yb 3+ energy transfer (ET) channel that reduces non-radiative transition losses. Compared with the Yb 3+ -free sample, the SLSO:1.0 %Fe 3+ , 3.0 %Yb 3+ sample exhibits a broadened FWHM from 115 nm to 180 nm, enhanced IQE and EQE of 98.1 % and 56.4 %, respectively, and 13 % improved thermal stability. Finally, a pc-LED device based on the SLSO:1.0 %Fe 3+ , 3.0 %Yb 3+ phosphor demonstrates potential for applications in NIR spectroscopy analysis, night vision, biomedical imaging, and other fields. This work lays a foundation for further research on strategies to regulation the optical properties of Fe 3+ -activated NIR phosphors.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Liping Fang,Kai Wang,Chen Han,Xinyong Li,Pei Li,Jieshan Qiu,Shaomin Liu
Piezocatalysis utilizes mechanical energy to achieve the required charge separation for redox reactions, a promising method for clean H 2 O 2 production. However, the efficiency of conventional piezocatalysts is limited by the undesirable low piezoelectricity. Herein, novel piezocatalysts composed of La, Sr, Co (Fe) in simple single perovskites (La 0.5 Sr 0.5 FeO 3-δ and La 0.5 Sr 0.5 CoO 3-δ ) and Ruddlesden-Popper (R-P) type perovskites (LaSrFeO 4-δ and LaSrCoO 4-δ ) are developed for piezocatalytic H 2 O 2 production. Results indicate that Fe-containing catalysts outperform Co-containing counterparts and the unique R-P perovskite oxides demonstrate significantly enhanced piezocatalytic performance than the corresponding single perovskites. For example, via piezocatalysis, the LaSrFeO 4-δ exhibits H 2 O 2 yields of 548 (in 10 % ethanol) and 247 µmol g −1 h −1 (without sacrificial agent), improved by a factor of 1.14, 4.94, or 21.73 compared to La 0.5 Sr 0.5 FeO 3-δ , LaSrCoO 4-δ , or La 0.5 Sr 0.5 CoO 3-δ , respectively. The piezoelectricity is an overwhelming factor in determining the H 2 O 2 generation. Furthermore, the piezoelectricity and oxygen vacancy (OV) content is well correlated. The R-P phase with lower OV exhibits a higher piezoelectricity because of the eliminated pining effect to the polarization domain reversion. Mechanism exploration suggests that H 2 O 2 formation stems from the efficient O 2 reduction via a 2-electron transferring pathway, during which the piezoelectric polarization drives the charge separation and transportation, favoring the redox reactions.
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Chemical Biology & Drug Design
·
2023
·Vol. 103
·期 1
·e14363
·
IF 3
Chun Li,Yuxin Xie,Shaoyu Hu,Hong Yu,Yunke Xu,Hongping Shen,Yuan Yuan,Long Gu,Bangming Pu
Hepatocellular carcinoma (HCC) is a life-threatening disease for which there is no cure. Traditional Chinese medicine is a treasure trove of Medicinals that has been used for thousands of years. In China, the traditional herb pair, Curcumae Rhizoma and Sparganii Rhizoma (CR-SR) represent a classic herbal combination used for the treatment of HCC. However, the drug targets and pharmacological mechanism of action of CR-SR in the treatment of HCC are unclear. To address this, we screened the active components and drug targets of CR-SR from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database and a high-throughput experiment- and reference-guided database of traditional Chinese medicines (HERB database). Combined with the weighted co-expression network analysis of dataset GSE76427, we constructed an active component-target-disease regulatory network. It was found that CR-SR's active components for HCC treatment included trans-gondoic acid, beta-sitosterol, stigmasterol, hederagenin, and formononetin. These compounds specifically targeted the genes Estrogen Receptor 1 ( ESR1 ), Cyclin A2 ( CCNA2 ), Checkpoint Kinase 1 ( CHEK1 ), and Nuclear Receptor Coactivator 2 ( NCOA2 ). ESR1 , CCNA2 , and CHEK1 genes showed significant differences in survival prognosis, expression levels, and statistical significance during the pathological stage. Moreover, their high affinity for formononetin was determined through molecular docking analysis. Cell assays and high-throughput sequencing were performed to reveal that the inhibitory effect of formononetin on HepG2 cell proliferation was related to hepatocyte metabolism and cell cycle regulation-related pathways. This study provides insights into potential HCC treatments.
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高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 46
·12566-12574
·
IF 5.976
Xiaohui Li,Lei Zhou,Miroslav D. Dramićanin,Qiang Tang,Xiping Jing,Jianxin Shi,Yiqin Xu,Mingmei Wu
Broad emission with a full and continuous color spectrum realized by crystal engineering is extensively desired to simulate natural sunlight and improve the white color quality. Herein, new insight into the modulation of B site order–disorder and intrinsic oxygen defects for complex perovskite (A3B′B2′′O9) Sr3−xScxZnNb2O9 (0 ≤ x ≤ 0.1) phosphors is demonstrated for broad-band emission via crystal engineering. We elucidate that the spectrum of Sr3ZnNb2O9 synthesized at an optimal temperature exhibits two emission bands under near-ultraviolet excitation (λex = 374 nm) which is readily available from near ultraviolet chips. The two broad emission bands can be ascribed to charge transfer from the empty 4d (t2g)-orbitals of Nb5+ ions to the filled 2p-orbitals of O2− ions and the intrinsic oxygen defects. Further, as a proposed strategy to optimize the luminescence property of Sr3ZnNb2O9 (SZN), we realized A-site nonequivalent doping to induce B-site disordering and cancel the luminescence quenching which results from B site ordering. The A-site nonequivalent doping efficiently offsets intrinsic oxygen defects, as validated by systematic analyses of experiments and DFT calculations. Consequently, the novel phosphor Sr3−xScxZnNb2O9 (x = 0.1) shows a high color rendering index (Ra = 82.2) and negligible color shift. In addition, its emission intensity is enhanced by ∼70 times as compared to the pristine Sr3ZnNb2O9.
研究领域:
材料科学
·
发光材料
·
固态化学
·
荧光粉
·
光学材料
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高影响因子
JOURNAL OF RARE EARTHS
·
2026
·
IF 9.6
Biao Xu,Zihao Xu,Chunyu Li,Jian Peng,Xingyu Li,Wubin Dai
Phosphor with thermally stable and highly efficient photoluminescence (PL) is a premise/challenge for use in high-quality phosphor-converted light-emitting diodes (pc-LEDs). Herein, via a facile solid-phase sintering method in air, a negative thermal quenching (TQ) blue emitting SrGa 2 B 2 O 7 (SGB): Bi is reported, mainly associating with the underlying collaborative effect of negative volumetric thermal expansion of rigid host, heterovalent substitution (Bi 3+ → Sr 2+ )-induced V Sr /V O vacancies, and generating self-reduction ions (Bi 2+ ). For charge balance under the condition of temperature rising, both opposite process of self-oxidation (Bi 2+ to Bi 3+ ) and charge release from trap levels can compensate blue-PL loss. This phosphor is comparable to Eu 2+ /Ce 3+ -activated blue-emitting phosphors, and even boasts superior quantum efficiency (QE) and thermal stability. Via artificially codoping Na + for charge compensation, the QE of the SGB:Bi/Na can be further significantly enhanced. Color-tunable PL is achieved via cascade-connected energy transfer (ET) from Bi 3+ to Tb 3+ (green)/Eu 3+ (red) in SGB: Bi/Na/Tb/Eu that possesses high QE/stability than the case of blue/green/red tricolor phosphor blends adopted in warm white LEDs (wLEDs). Finally, the SGB: Bi/Na and SGB: Bi/Tb/Eu/Na are respectively, encapsulated with distinct encapsulants via either traditional or remote “capping” packaging strategy to form blue LEDs and wLEDs, showcasing splendid electroluminescence behaviors and luciferous application prospects.
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