APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Zhenyu Zhang,Ning Wang,Xingzi Wang,Zheng Zhao,Chen Dong,Xianmin Tan,Yuanyuan Zheng,Zongyu Feng,Xiangxi Zhong,Juanyu Yang,Xiaowei Huang
With the linewidth of integrated circuits has progressively narrowed, imposing higher demands on the chemical mechanical polishing (CMP) process. Cerium oxide nanoparticles are widely used as abrasives in CMP, with their physical structure and the surface content of Ce 3+ ions and oxygen vacancies directly affecting their CMP performance. Here in, we synthesized La/Pr/Nd doped CeO 2 with the porous self-assembled spherical structures. Doping with La/Pr/Nd reduced the grain size of cerium oxide, increased its specific surface area, decreased the pore size, and increased the pore volume. HR-TEM analysis shows that the porous self-assembled spherical CeO 2 primarily exposes the (111) crystal facet. Additionally, the density functional theory (DFT) calculation, XPS, H 2 -TPR and XANES analyses shown that doping of La/Pr/Nd facilitated the formation of oxygen vacancies and increased the Ce 3+ content on the (111) crystal facet of the CeO 2 . La atoms are more likely to stabilize on the CeO 2 (111) surface compared to Pr and Nd atoms. The CMP results indicated that, The La-CeO 2 exhibited a higher MRR of 338 ± 7.54 nm/min, which is a 35 % increase compared to p-CeO 2 , and achieved superior surface roughness ( Ra = 0.201 ± 0.010 nm).
研究领域:
材料科学
·
纳米技术
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DOI
高影响因子
RSC Advances
·
2026
·Vol. 16
·期 32
·29712
·
IF 6.1
Yi Yang,Fengping Yu,Delong Ding,Chunliang Ge,Biao Chen,Xiaojiong Wu,Yaoji Chen,Hanfeng Lu,Hongfang Ma,Haitao Zhang,Weixin Qian,Weiyong Ying
To explore the influence of the rare earth element neodymium (Nd) on the production of light olefins (C = 2 –C = 4 ) via high-temperature Fischer–Tropsch synthesis (HTFT), a series of FeMn-based catalysts promoted with Nd and Na were synthesized using a combination of coprecipitation and incipient wetness impregnation techniques. These included Nd-modified FeMn x Nd ( x = 0, 0.1, 0.4, 0.7, 1, and 2), FeMnNa, and FeMn0.7NdNa catalysts. The results indicate that Nd reduces catalyst particle size and increases the BET specific surface area. Nd enhances surface basicity, increases the electron density around Fe atoms, suppresses hydrogen adsorption, and promotes CO dissociative adsorption, thereby facilitating the formation of χ-Fe 5 C 2 and improving Fischer–Tropsch synthesis (FTS) activity. However, excessive Nd loading results in Nd deposition on the catalyst surface, which decreases the BET surface area, induces particle agglomeration and growth, and inhibits catalyst reduction and carburization. These effects collectively reduce the content of χ-Fe 5 C 2 and lead to inferior FTS performance. In contrast, the synergistic interaction of Nd–Na suppresses the formation of θ-Fe 3 C, prevents particle agglomeration, and enhances the content of χ-Fe 5 C 2 , thereby significantly increasing CO conversion and light olefin yield. The FeMn0.7NdNa catalyst achieves a light olefin yield of 412.1 g h −1 kg Cat −1 , markedly surpassing that of FeMn0.7Nd and FeMnNa. Nd doping optimizes FeMn catalyst structure and electron density, promoting active χ-Fe 5 C 2 formation for high-temperature Fischer–Tropsch synthesis to light olefins.
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DOI
PubMed
高影响因子
HYDROMETALLURGY
·
2025
·
IF 5.3
Jun Li,Ruihui Wu,Shengjun Tian,Ronghao Liu,Huiying Wei,Yanzhao Yang
The NdFeB magnets are the most widely used permanent magnetic materials in the international arena, and the recovery of Nd(III) from the growing number of waste-NdFeB magnets is becoming increasingly crucial. In this study, a novel synergistic extractant consisting of bis(2,4,4-trimethylpentyl) phosphonic acid (Cyanex 272) and 8-hydroxyquinoline (8-HQ) is proposed for the recovery of Nd(III) from waste-NdFeB magnets. First, the influence of the ratio of the two extractants on the synergistic extraction coefficient was investigated. The coextraction coefficient ratio of the two extractants Cyanex 272 and 8-HQ was 1:1. The extraction behaviors under different conditions, such as the extractant concentration, aqueous phase pH (pH = 5), and oscillation time (1 min), were investigated. Under optimal conditions, the extraction efficiency reached 99.6 %. A chelating extraction mechanism was proposed on the basis of UV–vis spectroscopy, FT-IR spectroscopy, and NMR spectroscopy methods. The excellent extraction efficiency was maintained after five cycles of extraction and stripping, indicating the potential for application in light and heavy rare earth separation processes. Overall, this study aims to provide a new economically viable method for the recovery of Nd(III) from waste-NdFeB magnets.
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2023
·Vol. 170
·期 10
·103504
·
IF 3.9
Lu Chen,Qibin Tao,Lin Wang,Hao Lan,Qizhou Dai
In this study, a lead dioxide electrode co-modified with carbon microspheres and neodymium (CMS-Nd-PbO2) was prepared. The structural morphology and electrochemical properties of the four electrodes, PbO2, CMS-PbO2, Nd-PbO2, and CMS-Nd-PbO2, were compared by field emission scanning electron microscopy, X-ray diffractometer, X-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance, respectively. The results showed that the prepared CMS-Nd-PbO2 electrode had higher surface denseness and higher electrode activity. Based on the accelerated lifetime experiment, the actual working life of four electrodes was studied, and the CMS-Nd-PbO2 electrode had a relatively long lifetime, increased 24.60% compared with the PbO2 electrode. The influencing parameters of electrochemical degradation of bisphenol S (BPS) by CMS-Nd-PbO2 electrode, the ability of different electrodes to generate hydroxyl radicals, reaction mechanism, and the possible BPS degradation pathways were also discussed. Further, the safety of the prepared electrode was evaluated. Under the optimal parameters, the removal rate of BPS and chemical oxygen demand (COD) were 96.49% and 51.84%, respectively. The dissolved lead ion concentration in the solution after electrochemical oxidation was lower than the WHO standard. The CMS-Nd-PbO2 electrode showed promising applications in the degradation of emerging contaminants wastewater.
研究领域:
环境科学
·
电化学工程
·
材料科学
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Zhihao Zhang,Shendan Zhang,Chunjie Jiang,Haichuan Guo,Fengdong Qu,Yuichi Shimakawa,Minghui Yang
Distinguishing toxic gases among the various volatile sulfur compounds (VSCs) is of significant practical value for atmospheric and environmental pollution monitoring, industrial monitoring, and even for medical diagnostics (where VSCs are indicators of diseases). The particular challenge lies in the detection and discrimination of sulfur-containing gases such as dimethyl disulfide (DMDS), methyl sulfide (DMS), hydrogen sulfide (H 2 S), and carbon disulfide (CS 2 ) is of value. Herein, single-phase perovskite-type LnFeO 3 nanoparticles were prepared by the citrate sol-gel method. Their gas sensing characteristics regard to the four typical VSCs were investigated. We found that the gas response of the p-type semiconductor LnFeO 3 gas sensors to the four typical VSCs are significantly different. In addition, the sensors offer high performance, good tolerance to environmental changes and long-term stability for detecting VSCs gas at an operating temperature of 210 °C. A new design of sensor array was realized by integrating a series of LnFeO 3 materials, which revealed excellent recognition ability for various VSCs, showing promise for real time monitoring.
研究领域:
材料科学
·
环境科学
·
医学诊断
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DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 32
·15405-15414
·
IF 3.553
Wang Yige,Gao Bo,Wang Qian,Li Xiaohui,Su Zhi,Chang Aimin
The aim of this paper is to present a novel negative temperature coefficient (NTC) thermistor based on A 2 Zr 2 O 7 (A = Nd, Sm, Gd, Yb) zirconate ceramics with pyrochlore-type structure for high-temperature application. The zirconate ceramics were synthesized via a solid-state reaction method where rare-earth oxides and ZrO 2 were used as starting materials. The physical structures were characterized by X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. It was confirmed that Nd 2 Zr 2 O 7 and Sm 2 Zr 2 O 7 are pyrochlore phases, while Yb 2 Zr 2 O 7 and Gd 2 Zr 2 O 7 are defect fluorite phases. The electrical property investigated by using resistance–temperature measurements demonstrated that the prepared A 2 Zr 2 O 7 zirconate ceramics exhibit a typical characteristic of NTC over a wide temperature range between 673 and 1273 K. Particularly, A 2 Zr 2 O 7 , in addition to having high activation energy to ensure better sensitivity, can still maintain higher resistivity under high-temperature environments. Furthermore, the resistivity of A 2 Zr 2 O 7 is almost independent of the change in oxygen partial pressure. These properties are superior to the classical spinel-type or perovskite-type NTC thermistor, providing valuable information to explore new NTC thermistor for high-temperature applications.
研究领域:
材料科学
·
电子工程
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 103
·期 4
·2727-2740
·
IF 3.094
Fushuo Wu,Peng Wu,Yunxuan Zhou,Xiaoyu Chong,Jing Feng
In this work, RENbO 4 (RE = Y, La, Nd, Sm, Gd, Dy, Yb) ceramics with low density, low Young's modulus, low thermal conductivity, and high thermal expansion have been systematically investigated, the excellent thermo-mechanical properties indicate that RENbO 4 ceramics possess the potential as the new generation of thermal barrier coatings (TBCs) materials. X-ray diffraction and Raman spectroscopy phase structure identification reveal that all dense bulk specimens obtained by high-temperature solid-state reaction belonged to the monoclinic (m) phase with C12/c1 space group. The ferroelastic domains are detected in the specimens, revealing the ferroelastic transformation between tetragonal (t) and monoclinic (m) phases of RENbO 4 ceramics. The Young's modulus and hardness of the RENbO 4 ceramics measured by the NanoBlitz 3D nanoindentation method are discussed in details, and the lower Young's modulus (60-170 GPa) and higher hardness (the maximum value reaches 11.48 GPa) indicating that higher resistance of RENbO 4 ceramics to failure and damage. Lower thermal conductivity (1.42-2.21 W [m k] −1 at 500°C-900°C) and lower density (5.330-7.400 g/cm 3 ) than other typical TBCs materials give RENbO 4 ceramics the unique advantage of being new TBCs materials. Meanwhile, the thermal expansion coefficients of RENbO 4 ceramics reach 9.8-11.6 × 10 −6 k −1 and are comparable or higher than other typical TBCs materials. According to the first-order derivative of the thermal expansion rate, the temperature of the ferroelastic transformation of RENbO 4 ceramics can be observed.
研究领域:
材料科学
·
固体力学
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2017
·Vol. 101
·期 3
·1266-1278
·
IF 2.841
Lin Chen,YeHua Jiang,XiaoYu Chong,Jing Feng
Thermal barrier coatings (TBCs) are one of the most important materials in gas turbine to protect the high temperature components. RETa 3 O 9 compounds have a defect-perovskite structure, indicating that they have low thermal conductivity, which is the critical property of TBCs. Herein, dense RETa 3 O 9 bulk ceramics were fabricated via solid-state reaction. The crystal structure was characterized by X-ray diffraction (XRD) and Raman Spectroscope. Scanning electron microscope (SEM) was used to observe the microstructure. The thermophysical properties of RETa 3 O 9 were studied systematically, including specific heat, thermal diffusivity, thermal conductivity, thermal expansion coefficients, and high-temperature phase stability. The thermal conductivities of RETa 3 O 9 are very low (1.33-2.37 W/m·K, 373-1073 K), which are much lower than YSZ and La 2 Zr 2 O 7 ; and the thermal expansion coefficients range from 4.0 × 10 −6 K −1 to 10.2×10 −6 K −1 (1273 K), which is close to La 2 Zr 2 O 7 and YSZ. According to the differential scanning calorimetry (DSC) curve there is not phase transition at the test temperature. Due to the high melting point and excellent high-temperature phase stability with these oxides, RETa 3 O 9 ceramics were promising candidate materials for TBCs.
研究领域:
材料科学
·
热物理
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Hongfeng Chai,Ying Li,Yifan Luo,Marc Debliquy,Chao Zhang
The early detection of lung cancer by breath analysis has attracted more and more attention. In this work, high-performance LnFeO 3 (Ln = Nd, Dy, Er) based isopropanol sensors were synthesized by microwave-assisted hydrothermal method. X-ray diffraction, field-emission scanning electron microscope, transmission electron microscope, and UV–visible-near infrared absorption spectrometer were used to analyze the material phase composition, microstructure, and other physical properties. The sensing performance was tested by using a four-channel gas testing chamber. The sensors were tested with low concentrations of isopropanol at high humidity to simulate a real human exhaled breath environment. The low binding energy of the Ln-O bond makes it easy to have chemical reactions, which leads to excellent isopropanol sensing performance. Finally, the gas sensing mechanism of the LnFeO 3 sensor was discussed.
研究领域:
材料科学
·
医学诊断
·
传感器技术
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DOI
高影响因子
Small
·
2024
·
IF 13
Quanliang Mao,Mengyin Gu,Chengyuan Hong,Huiying Wang,Xinzhong Ruan,Zhusheng Liu,Bo Yuan,Mengting Xu,Chen Dong,Lei Mou,Xiang Gao,Guangyu Tang,Tianxiang Chen,Aiguo Wu,Yuning Pan
Personalized radiotherapy strategies enabled by the construction of hypoxia-guided biological target volumes (BTVs) can overcome hypoxia-induced radioresistance by delivering high-dose radiotherapy to targeted hypoxic areas of the tumor. However, the construction of hypoxia-guided BTVs is difficult owing to lack of precise visualization of hypoxic areas. This study synthesizes a hypoxia-responsive T 1 , T 2 , T 2 mapping tri-modal MRI molecular nanoprobe (SPION@ND) and provides precise imaging of hypoxic tumor areas by utilizing the advantageous features of tri-modal magnetic resonance imaging (MRI). SPION@ND exhibits hypoxia-triggered dispersion-aggregation structural transformation. Dispersed SPION@ND can be used for routine clinical BTV construction using T 1 -contrast MRI. Conversely, aggregated SPION@ND can be used for tumor hypoxia imaging assessment using T 2 -contrast MRI. Moreover, by introducing T 2 mapping, this work designs a novel method (adjustable threshold-based hypoxia assessment) for the precise assessment of tumor hypoxia confidence area and hypoxia level. Eventually this work successfully obtains hypoxia tumor target and accurates hypoxia tumor target, and achieves a one-stop hypoxia-guided BTV construction. Compared to the positron emission tomography-based hypoxia assessment, SPION@ND provides a new method that allows safe and convenient imaging of hypoxic tumor areas in clinical settings.
研究领域:
医学影像
·
放射学
·
肿瘤学
·
分子成像
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 45
·27969-27977
·
IF 3.361
Yaoyang Liu,Sheng Liu,Zhibin Liu,Chuang Zhao,Chunhui Li,Yu Zhou,Caishan Jiao,Yang Gao,Hui He,Shaowen Zhang
A novel asymmetric diglycolamide N,N-dimethyl-N′,N′-dioctyl diglycolamide (LII) was synthesized. The Nd(III) extraction behavior from HNO3 and loading capability of the solution of LII in 40/60 (v/v)% n-octanol/kerosene were studied. Analyses by the slope method, ESI-MS, and FT-IR indicated that, similar to the previously studied isomer ligand N,N′-dimethyl-N,N′-dioctyl diglycolamide (LI), 1 : 3 Nd(III)/LII complexes formed. Under the same experimental conditions, the distribution ratio and limiting organic concentration of LII towards Nd(III) were smaller than those of LI, but the critical aqueous concentration of LII was larger, which implies that LII exhibited poorer extraction and loading capabilities towards Nd(III) than LI, and LII has a tendency to be less likely to form the third phase. The quasi-relativistic density functional theory (DFT) calculation was performed to provide some explanations for the differences in their extraction behaviors. The electrostatic potential of the ligands indicated that the electron-donating ability of the amide O atoms in LII displayed certain differences compared with LI. This inhomogeneity in LII affected the interaction between LII and Nd(III), as supported by QTAIM and bonding nature analysis, and it seemed to reflect in the extraction performance towards Nd(III).
研究领域:
化学
·
材料科学
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DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 5.6
Xin Wang,Yujie Ren,Wenge Fan,Qingqing Zhu,Peilin Yuan,Peng Jin,Xiaodong Wei,Chufeng Sun
Yttria-stabilized zirconia (YSZ) ceramic-based flow passage components are highly susceptible to cavitation erosion. To counter this limitation, rare-earth oxide (REO, RE=La, Ce, Nd, Gd) doped YSZ with superior cavitation erosion resistance was successfully prepared using spark plasma sintering technology. The microstructures, phase compositions, mechanical properties, and cavitation erosion resistance of YSZ and REYSZ were investigated. The results indicate that REO doping promoted the generation of t'- and c-phases, leading to a denser structure and grain refinement. Moreover, the presence of a larger concentration of the t'-phase resulted in a higher microhardness and elastic modulus. Owing to its superior mechanical properties, fine grains and high density, REYSZ exhibited improved cavitation erosion resistance. Particularly, NdYSZ exhibited 12.4 times higher cavitation-erosion resistance than that of YSZ. Furthermore, the grain boundaries of YSZ contain special m-phase bands, which are also responsible for the quicker exfoliation of grains during cavitation erosion. The segregation of rare earth elements at the grain boundaries inhibited the generation of m-phase bands, resulting in a longer cavitation erosion incubation period for REYSZ.
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DOI
高影响因子
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