SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Qing Liu,Huifang Xing,Yan Zhang,Yunze Zhao,Meng Rong,Huizhou Liu,Liangrong Yang
The metatitanic acid H 2 TiO 3 (HTO) with high selectivity shows potential in lithium extraction from salt lake brine. Nevertheless, the sluggish adsorption kinetics and unsatisfying actual adsorption capacity hinder H 2 TiO 3 industrial application. Herein, a rare earth element Nd-doped H 2 TiO 3 (Nd-HTO-1 %) was synthesized. The crystallinity, morphology, hydrophilicity, adsorption property and mechanism of Nd-HTO-1 % were systematically characterized by a series of techniques. Interestingly, Nd-doping promotes the generation of oxygen vacancies, thereby increasing the density of surface hydroxyl groups and making the surface high-hydrophilic and particle size decreased. After 1 % Nd-doping, high-hydrophilic HTO was obtained with a contact angle of 16.5°. The adsorption capacity of Nd-HTO-1 % increased by 12.5 % compared with HTO, and the equilibrium time of adsorption reduced by half to 4 h. After eight cycles, Nd-HTO-1 % still showed a considerable adsorption capacity of 39.69 mg·g −1 . In the meantime, the dissolution loss of titanium is merely 0.14 %, showing excellent cycling stability. Combined with the considerable selectivity exhibiting in Qarhan salt lake brine, it demonstrates potential in utilization of Nd-doped H 2 TiO 3 for lithium extraction from salt lake brine.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Hongqi Chen,Wen Wang,Changchun Ji,Lun Wang
The core–shell NaGdF 4 :Yb,Er@NaGdF 4 :Yb,Nd upconversion nanoparticles (UCNPs) were successfully obtained with the method of co-precipitation, and the water-solubility of UCNPs was improved by the ligand exchange reaction between nitrosyl tetrafluoroborate (NOBF 4 ) and nanoparticles. The IR-783 dye with negative charge and NOBF 4 -UCNPs with positive charge can bind together by electrostatic action to sensitize UCNPs through the energy transfer from IR-783 to UCNPs. However, with the presence of Na 2 S (a commonly used H 2 S donor), a highly selective reaction between H 2 S and IR-783, which destoried the structure of IR-783 and blocked the energy transfer, thus led to the quenching of luminescent intensity. Based on this, a sensing system for determination of H 2 S has been constructed successfully. The linear range of H 2 S detection by this system is 0.5–15 μM, and the detection limit is 34.17 nM. Furthermore, the dye-sensitized core–shell NaGdF 4 :Yb,Er@NaGdF 4 :Yb,Nd upconversion nanoprobe was applied to real sample analysis with satisfactory results.
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PubMed
高影响因子
MATERIALS & DESIGN
·
2025
·
IF 7.9
Yuhan Yang,Haohao Ji,Mengmeng Xie,Dewen Wang,Wenhao Zhou,Jian Zhang,Yu Liu,Shiwei Wang,Zheng Wang
Gradient doping of Nd: YAG (Nd: Y 3 Al 5 O 12 ) can relieve thermal effect during laser operation in solid-state lasers. Direct ink writing (DIW) is an effective method for fabricating gradient-doped structures. However, the delay issue during component switching significantly affects rare-earth ion concentration distribution in the samples, which includes delivery delay and transitional delay. They were respectively optimised by reducing the volume of mixing zone and by modifying component switching mode. Firstly, simulations of the mixing zone before and after optimisation were conducted using ANSYS Fluent to demonstrate the mixing uniformity. Secondly, the processes of component changes during extrusion were simulated to demonstrate the effectiveness of the two delay optimisation methods. Line patterns were printed using DIW with varying mixing zone volumes and component switching modes. The delay optimisation methods were confirmed to significantly reduce the impact of the delay by measuring Nd 3+ ion concentration. Furthermore, a mathematical model was developed to assess the influence of two delay optimisation methods on the delay. Finally, 0–0.5–1–0 at% Nd: YAG gradient-doped laser ceramics were successfully fabricated based on the proposed delay optimisation method, and the performance characterization of the Nd: YAG laser ceramics confirmed the efficacy of the method.
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JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 106
·期 11
·7009-7018
·
IF 3.9
Yong Ge,Baoliang Xu,Yiliao Liao,Xueyu Zhang,Xu Yan,Caohui Zheng,Tao Duan
Multiphase ceramics have a high application potential in the field of nuclear waste immobilization because of the efficient synergy between the individual phases. In this work, zirconia/garnet multiphase ceramics with high efficient and effective immobilization capacity of trivalent actinides were successfully prepared using conventional solid-phase sintering. ZrO 2 doping increases the lattice site available for nuclide substitution and advance the immobilization capacity of the ceramic substrate for nuclide. At the same time, the phase change of zirconia is used to tougher and improve the physical properties of the ceramic waste form. The feasibility of using multiphase ceramics for the efficient immobilization of trivalent actinides was assessed by studying the phase evolution, microstructure, Vickers hardness, and chemical stability of the multi-phase ceramics. Zr 1- x Nd x O 2- x /2 /Ca 3- y Nd y Zr 3- y Fe y -1 Fe 3 O 12 multiphase ceramics exhibited superior physical or chemical properties compared to most of the multiphase ceramics as well as the previously prepared single-phase calcium garnet ceramic waste forms. The Vickers hardness of all the multiphase ceramic samples ranged between 685 and 730 HV0.5. Under the condition of using simulate Bei Shan groundwater as leaching agent, the normalized leaching rates of Nd is approximately 10 − 6 g · m −2 · day −1 , showing good chemical stability and achieving efficient and effective immobilization of trivalent actinides. The excellent chemical, as well as physical properties of Zr 1- x Nd x O 2- x /2 /Ca 3- y Nd y Zr 3- y Fe y -1 Fe 3 O 12 multiphase ceramics are expected to make them one of the substrates for more efficient and effective immobilizing of trivalent actinides.
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高影响因子
Journal of Advanced Ceramics
·
2022
·Vol. 11
·期 4
·629-640
·
IF 11.534
Guo Weijia,Ma Zhiyu,Luo Yu,Chen Yugu,Yue Zhenxing,Li Longtu
Low-loss tungsten-bronze microwave dielectric ceramics are dielectric materials with potential application value for miniaturized dielectric filters and antennas in the fifth-generation (5G) communication technology. In this work, a novel Al/Nd co-doping method of Ba 4 Nd 9.33 Ti 18 O 54 (BNT) ceramics with a chemical formula of Ba 4 Nd 9.33+ z /3 Ti 18− z Al z O 54 (BNT-AN, 0 ⩽ z ⩽ 2) was proposed to improve the dielectric properties through structural and defect modulation. Together with Al-doped ceramics (Ba 4 Nd 9.33 Ti 18− z Al 4 z /3 O 54 , BNT-A, 0 ⩽ z ⩽ 2) for comparison, the ceramics were prepared by a solid state method. It is found that Al/Nd co-doping method has a significant effect on improving the dielectric properties compared with Al doping. As the doping amount z increased, the relative dielectric constant ( ε r ) and the temperature coefficient of resonant frequency ( τ f ) of the ceramics decreased, and the Q×f values of the ceramics obviously increased when z ⩽ 1.5. Excellent microwave dielectric properties of ε r = 72.2, Q×f = 16,480 GHz, and τ f = +14.3 ppm/°C were achieved in BNT-AN ceramics with z = 1.25. Raman spectroscopy and thermally stimulated depolarization current (TSDC) technique were firstly combined to analyze the structures and defects in microwave dielectric ceramics. It is shown that the improvement on Q×f values was originated from the decrease in the strength of the A-site cation vibration and the concentration of oxygen vacancies ( \({\rm{V}}_{\rm{O}}^{ \cdot \cdot }\) ), demonstrating the effect and mechanism underlying for structural and defect modulation on the performance improvement of microwave dielectric ceramics.
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高影响因子
CURRENT APPLIED PHYSICS
·
2022
·
IF 2.856
Xiyue He,Bijun Fang,Shuai Zhang,Xiaolong Lu,Jianning Ding
0.5 mol% Nd-doped (Ba 0.85 Ca 0.15 )(Ti 0.9 Hf 0.1 )O 3 (BCTH-Nd) lead-free ceramics were prepared by a solid-phase twin crystal method, where the effects of sintering condition on structure, electrical and optical properties were studied. All the sintered BCTH-Nd ceramics exhibit pure perovskite structure, dense microstructure with several micron grain size , which tends to increase with elevating sintering temperature. All synthesized ceramics have complex dielectric behavior, which presents normal ferroelectrics characteristic with slight dispersion phenomenon. The BCTH-Nd ceramics exhibit excellent piezoelectric and ferroelectric properties and acceptable dielectric performance when sintered at 1480 °C for 2 h. Under 269 nm light excitation, several fluorescent emission peaks are excited with a whole indigo fluorescence, where the strongest emission peak is emitted at 473 nm, corresponding to the 4 G 3/2 → 4 I 9/2 energy level transition of Nd 3+ . Multifunctional performance is fulfilled in the lead-free BCTH ceramics via rare earth doping, which can broaden the application fields of piezoelectric-based materials.
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高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
Wen-Jing Shi,Zhen-Hong He,Mei-Xia Yang,Yue Tian,Lu-Ting Pan,Xin-Yan Wei,Weitao Wang,Kuan Wang,Huan Wang,Zhao-Tie Liu
Utilizing renewable energy-derived H2 to convert CO2 into valuable chemicals represents a crucial strategy for achieving carbon emission reduction and enabling resource utilization. Conventional photocatalytic CO2 methanation, however, is hindered by low activity and inefficient energy utilization, limiting its practical application. In the present work, we developed a Cu and Nd co-doped Co3O4 catalyst that synergistically harnesses both light and thermal energy for photothermal catalytic CO2 methanation. The optimized catalyst with a molar ratio of 9/1/1 for Co/Cu/Nd (denoted as CCNO-9) achieves a remarkable CH4 formation activity of 27.3 mmol·gcat-1·h-1 at 200 °C, especially at ambient pressure. The incorporation of foreign Cu and Nd atoms in Co3O4 lattice induces the formation of abundant heterogeneous interfaces and oxygen vacancies, thereby exposing additional active sites for CO2 adsorption and activation. In-situ DRIFTS studies revealed that the Nd promotes the conversion of CO2 into *HCO3- and *COOH key intermediates. The photothermal synergy significantly enhances the reaction. Photoexcitation generates electrons and holes for CO2 reduction, while the thermal energy assists in overcoming the reaction energy barriers. DFT calculations confirmed that the CCNO-9 catalyst requires the lowest energy barrier for the rate-determining step from *COOH to *CH4. This study presents a very active and stable photothermal catalytic system for efficient CO2 conversion, advancing the development of low-carbon catalytic technologies.
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APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2020
·Vol. 126
·期 11
·1-14
·
IF 1.81
Shi Feng,Xiao En-Cai,Chen Guohua,Chen Ying
Non-stoichiometric Nd[Mg 0.5 Sn 0.5(1+ x ) ]O 3 (− 0.04 ≤ x ≤ + 0.04)—type samples were prepared using a traditional two-step solid-state sintering process. Their crystal structures, phase compositions, dielectric properties and lattice vibrational characteristics were identified in detail. The double perovskite Nd(Mg 0.5 Sn 0.5 )O 3 with a monoclinic structure was distinguished as the main crystalline phase, and pure phase was obtained when x < 0. The sample [Nd(Mg 0.5 Sn 0.49 )O 3 ] at x = − 0.02 shows the excellent dielectric properties: ε r = 18.74, Q × f = 47,979 GHz. The lattice vibrational characteristics were clarified with Raman and infrared active mode spectroscopy. The intrinsic properties were fitted by four-parameter semi-quantum model, which show that the low-frequency infrared modes yield a more significant contribution to permittivity and dielectric loss. Raman shifts of modes F 2g (A) and F 2g (B) correlate with dielectric constants negatively, which implies that the bond length has a positive correlation with permittivity. Full widths at half maximum of vibrational modes A 1g (O) correlate with dielectric loss values positively and correlate with the degree of order ( S ) negatively.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 4
·3274-3280
·
IF 2.22
Du Kang,Zou Zheng-Yu,Song Xiao-Qiang,Fan Jun,Lu Wen-Zhong,Lei Wen
Novel Ca RE 4 Si 3 O 13 (RE = La, Nd, Sm, and Er) microwave dielectric ceramics were prepared using solid-state reaction sintered at 1350–1400 °C for 5 h. CaRE 4 Si 3 O 13 (RE = La, Nd, Sm, and Er) possessed an apatite structure with the P 6 3 /m space group. The lattice parameters a , b and c ; theoretical density and unit cell volumes of CaRE 4 Si 3 O 13 (RE = La, Nd, Sm, and Er) gradually decreased when RE changed from La to Er, and a pure phase was formed at all compositions. The ε r , Q × f , and τ f values of the CaRE 4 Si 3 O 13 (RE = La, Nd, Sm, and Er) ceramics were related to the total ionic polarizability, packing fraction, and polyhedral distortion of RE/Ca(2)O 7 , respectively. The optimal microwave dielectric properties of the CaRE 4 Si 3 O 13 ceramics ( ε r = 13.37, Q × f = 18,600 GHz, and τ f = − 17.8 ppm/°C) were obtained at RE = Er.
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高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Wei Cai,Xinqi Zhang,Jianwei Zheng,Jingwu Zheng,Rongyao Li,Haibo Chen,Liang Qiao,Yao Ying,Wangchang Li,Jing Yu,Juan Li,Shenglei Che
To address the operational safety hazards associated with using high-concentration inorganic phosphoric acid as a surface treatments to enhance the high-temperature oxidation resistance of Nd-Fe-B magnetic powders, this study innovatively proposes an environmentally friendly organic phosphonic acid (methylene diphosphonic acid, MDPA) as an alternative solution. By comparing the effects of inorganic phosphoric acid and MDPA surface treatments on the magnetic properties and thermal stability of magnetic powders, it was found that phosphating-treated samples exhibited slight decrease in coercivity H cj and maximum magnetic energy product (BH) max at room temperature compared to untreated samples. However, at 340 °C, the (BH)max and Hcj of untreated samples dropped sharply by 98.55 % (from 4.97 to 0.07 MGOe) and 92.72 % (from 9.62 to 0.70 kOe), respectively. In contrast, the inorganic phosphate-treated samples showed only a slight decline of 13.55 % (from 4.53 to 3.92 MGOe) and 1.22 % (from 9.39 to 9.28 kOe). The MDPA-treated samples exhibited the best thermal stability, with minimal losses in both (BH)max and Hcj, decreasing by only 6.88 % (from 4.66 to 4.34 MGOe) and 0.69 % (from 9.43 to 9.36 kOe), respectively. Microstructural analysis revealed that the dense metal phosphate conversion layer formed during phosphating was the key to maintaining high-temperature magnetic performance. Specifically, inorganic phosphoric acid treatment preferentially corroded Nd-rich intergranular phases, resulting in a higher Nd content in the conversion layer. In contrast, the iron phosphate salt formed by MDPA treatment dominates the transformation layer, effectively reduces the damage to the microstructure of the magnetic powder. Our research provides a surface treatment solution that combines safety and efficiency for the performance protection of rare-earth magnetic powders in high-temperature injection molding processes.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Jing Wang,Zhong Yang,Jianyong Jiang,Chaoyong Deng,Kongjun Zhu
Flexible dielectric materials with benign energy storage performance are highly desirable for the miniaturization, portability and integration of modern electronics. However, the limited energy storage density seriously restricts their practical applications. Herein, multilayered composite films composed of the P(VDF-HFP) matrix and Nd doped BaTiO 3 nanofibers with various filling ratios, layer numbers and topological structures were systematically designed and constructed via the layer-by-layer non-equilibrium process. The 3-layered composite films (3.0 wt% filling ratio) with the pure P(VDF-HFP) layer adjacent to the electrodes revealed good mechanical behavior, greatly enhanced captured ions at interfacial regions and suppressed injected charges from electrodes, which facilitated the improvement of the breakdown strength and discharged energy density. And a maximum U e of 25.5 J/cm 3 with a E b of 719.9 MV/m was achieved, which was not only 1.4 times more than the pure P(VDF-HFP) via the same process, but also behaved better than counterparts with the similar filling ratios and was among the top U e values of related P(VDF-HFP)-based nanocomposites.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Maowa Zhang,Haiqing Hao,Chenxi Shi,Chongchong Chen,Guoli Zhou,Jingtao Wang,Yijun Cao,Xiangke Han
Nd is a strategic metal, but its extraction and separation process remains a challenging task. Here, ion-imprinted membranes with six-coordinated and semi-rigid imprinted nanocage structure were developed by self-assembling terpyridine monomers in the confined reduced graphene oxide (rGO) nanochannels. The obtained membranes displayed excellent Nd(III) adsorption capacity of 20.6 mg g −1 in the solution including seven rare earth elements (REEs), together with a 7.68 times higher selectivity to Y(III). Experimental measurements and theoretical calculations revealed that Nd(III) was well coordinated to the six pyridine-nitrogen in the nanocage, which showed shorter average coordination bond (0.77 Å) and stronger binding energy (-10.52 eV) than other REEs. These were mainly attributed to the rigid symmetrical crab-type architecture and specific cavity size of bis-terpyridine nanocage. Meanwhile, the limited decomposition of these metastable nanocage derived from 2D confined effect and nanochannel walls with few groups reduced the interference of groups at non-imprinted sites on selective adsorption. The excellent anti-swelling property of rGO framework endowed 7 static adsorption cycles and maintained high selectivity (K' (Nd/Y) > 7). Integrated into account the well-defined semi-rigid sites constituted by non-covalent interactions, this strategy provided a new idea for facile synthesis of imprinted sites with higher selectivity.
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