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Low-dose X-ray induced long afterglow NIR luminescence from Cr3+ doped Zn1–xCdxGa2O4 spinel solid solutions 掺杂 Cr3+ 的 Zn1-xCdxGa2O4 尖晶石固溶体的低剂量 X 射线诱导长余辉近红外发光
IF 5.2 1区 化学 Q1 CHEMISTRY, APPLIED Pub Date : 2025-02-01 DOI: 10.1016/j.jre.2023.12.006
Tingting Zhao , Wenzhi Sun , Shuya Wang , Wei Meng , Chunqing Fu , Xiaoyan Fu , Hongwu Zhang
The low-dose X-ray induced long afterglow near infrared (NIR) luminescence from Cr3+ doped Zn1–xCdxGa2O4 spinel solid solutions was investigated. The structure analysis shows the good formation of Zn1–xCdxGa2O4 spinel solid solutions, which possesses a cubic spinel structure with Fd3m space group. The formation of Zn1–xCdxGa2O4 spinel solid solutions induces the obvious increase of long afterglow near infrared luminescence excited by low-dose X-ray. When the content of doped Cd2+ reaches 0.1, the low-dose X-ray induced long afterglow NIR luminescence is the maximum. More importantly, only 5 s X-ray irradiation can induce more than 6 h NIR afterglow emission, of which the afterglow luminescent intensity is still 5 times stronger than the background intensity after 6 h. The thermoluminescent results show that under the 5 s exposure of X-ray, the trap density of Zn0.9Cd0.1Ga2O4:Cr3+ is much higher than that of ZnGa2O4:Cr3+. The replacement of Cd2+ ions with large radius at Zn2+ sites causes the increase of defects and dislocations, which results in the obvious increase of trap concentrations. And the addition of high-z number elements Cd2+ would enhance the X-ray absorption of the solid solutions, which thus can be easily excited by low-dose X-ray. Zn0.9Cd0.1Ga2O4:1%Cr3+ solid solution is a potential candidate of low-dose X-ray induced long afterglow luminescent materials.
研究了掺杂 Cr3+ 的 Zn1-xCdxGa2O4 尖晶石固溶体的低剂量 X 射线诱导长余辉近红外发光现象。结构分析表明 Zn1-xCdxGa2O4 尖晶石固溶体形成良好,具有 Fd3m 空间群的立方尖晶石结构。Zn1-xCdxGa2O4 尖晶石固溶体的形成明显增加了低剂量 X 射线激发的长余辉近红外发光。当掺杂 Cd2+ 的含量达到 0.1 时,低剂量 X 射线激发的长余辉近红外发光达到最大值。更重要的是,仅 5 秒的 X 射线照射就能诱发超过 6 小时的近红外余辉发射,其中 6 小时后的余辉发光强度仍比背景强度强 5 倍。热释光结果表明,在 5 s 的 X 射线照射下,Zn0.9Cd0.1Ga2O4:Cr3+ 的阱密度远高于 ZnGa2O4:Cr3+。在 Zn2+ 位点上置换大半径的 Cd2+ 离子会导致缺陷和位错的增加,从而使陷阱浓度明显增加。而高 Z 数元素 Cd2+ 的加入会增强固溶体对 X 射线的吸收,因此很容易被低剂量 X 射线激发。Zn0.9Cd0.1Ga2O4:1%Cr3+ 固溶体是低剂量 X 射线诱导长余辉发光材料的潜在候选材料。
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引用次数: 0
Construction of novel spherical ZnIn2S4–Ag–LaFeO3 heterostructures for enhancing photocatalytic efficiency 构建新型球形 ZnIn2S4-Ag-LaFeO3 异质结构以提高光催化效率
IF 5.2 1区 化学 Q1 CHEMISTRY, APPLIED Pub Date : 2025-02-01 DOI: 10.1016/j.jre.2024.02.002
Dongsheng Jia, Jiaxuan Pan, Dongliang Zhang, Mitang Wang, Ying Li
Herein we report novel photocatalysts ZnIn2S4–Ag–LaFeO3 with the core–shell structured materials prepared by hydrothermal method. In order to improve the efficiency of photocatalytic degradation of pollutants, LaFeO3 was prepared by hydrothermal followed by calcination, and further Ag nanoparticle (NP) was loaded onto the spherical structure of LaFeO3 by photolysis of silver nitrate, and finally the spherical ZnIn2S4–Ag–LaFeO3 photocatalyst was prepared by hydrothermal method again. The structure and properties of the as-prepared materials were characterized by X-ray photoelectron spectroscopy, ultraviolet–visible absorption spectroscopy, X-ray diffraction, scanning electron microscopy and fluorescence spectra. The results show that the synthesized composite photocatalysts display a significant improvement in photocatalytic efficiency relative to the single LaFeO3 and ZnIn2S4 and form a core–shell structure. Furthermore, the effect of the ratio of each component on the photocatalytic efficiency was investigated in detail, and it is discovered that at an Methylene Blue (MB) concentration of 0.219 mol/L, the degradation rate of MB is 95% at 120 min using 0.02 g of catalyst with an ideal ZnIn2S4:Ag:LaFeO3 ratio of 10:0.5:1. The possible mechanisms to improve the photocatalytic efficiency were explored.
在此,我们报告了通过水热法制备的具有核壳结构材料的新型光催化剂 ZnIn2S4-Ag-LaFeO3。为了提高光催化降解污染物的效率,我们采用水热法制备了煅烧后的 LaFeO3,并利用硝酸银的光解作用将银纳米粒子(NP)负载到球形结构的 LaFeO3 上,最后再次采用水热法制备了球形的 ZnIn2S4-Ag-LaFeO3 光催化剂。通过 X 射线光电子能谱、紫外可见吸收光谱、X 射线衍射、扫描电子显微镜和荧光光谱对所制备材料的结构和性质进行了表征。结果表明,与单一的 LaFeO3 和 ZnIn2S4 相比,合成的复合光催化剂的光催化效率显著提高,并形成了核壳结构。此外,还详细研究了各组分比例对光催化效率的影响,发现在亚甲基蓝(MB)浓度为 0.219 摩尔/升时,理想的 ZnIn2S4:Ag:LaFeO3 比例为 10:0.5:1,使用 0.02 克催化剂,120 分钟内 MB 的降解率为 95%。探讨了提高光催化效率的可能机制。
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引用次数: 0
Temperature sensing performance of Er3+:Yb3+ co-doped CaF2 ceramic powders using near-infrared light 使用近红外线检测 Er3+:Yb3+ 共掺杂 CaF2 陶瓷粉末的温度传感性能
IF 5.2 1区 化学 Q1 CHEMISTRY, APPLIED Pub Date : 2025-02-01 DOI: 10.1016/j.jre.2024.01.005
Nikifor Rakov , Francisco Matias , Glauco S. Maciel
Luminescent materials for application in temperature sensing have caught a lot of interest in recent years. Particularly erbium (Er3+)-doped fluoride-based materials (EFM), which are readily accessible by near-infrared (NIR) excitation to produce efficient photon conversion. It has been established that ytterbium (Yb3+) may improve the performance of EFMs in both bulk and nanostructured forms by energy transfer channels among rare-earth ions in interstitial clusters. In this work, a comprehensive analysis of the Er3+:Yb3+:CaF2 crystalline structure, photoluminescence, and energy transfer from Yb3+ to Er3+ is presented for powders prepared by combustion synthesis. The Er3+:Yb3+:CaF2 powders display exceptional photon down-shift and up-conversion when exposed to NIR light (λ = 975 nm). The luminescence spectral change of the NIR emission around 1.5 μm, which corresponds to the Er3+ electronic transition 4I13/2 → 4I15/2, was investigated in a temperature range of 298–423 K for application in temperature sensing of biological systems exploring the third biological window. The luminescence intensity ratio technique was applied to the thermally coupled Stark sublevels of states 4I13/2 and 4I15/2 with the highest estimated temperature relative sensitivity being around 0.4 %/K at 298 K.
近年来,用于温度传感的发光材料备受关注。特别是掺杂铒(Er3+)的氟化物基材料(EFM),很容易在近红外(NIR)激发下产生高效的光子转换。镱(Yb3+)可通过间隙团簇中稀土离子间的能量转移通道改善块状和纳米结构形式的 EFM 性能,这一点已得到证实。本研究全面分析了燃烧合成法制备的 Er3+:Yb3+:CaF2 粉末的晶体结构、光致发光以及从 Yb3+ 到 Er3+ 的能量传递。Er3+:Yb3+:CaF2 粉末在近红外光(λ = 975 纳米)照射下显示出优异的光子下移和上转换性能。在 298-423 K 的温度范围内,研究了 1.5 μm 附近近红外发射的发光光谱变化,该光谱与 Er3+ 电子转变 4I13/2 → 4I15/2 相对应,可应用于探索第三生物窗口的生物系统温度传感。发光强度比技术适用于热耦合斯塔克亚级态 4I13/2 和 4I15/2,在 298 K 时,估计的最高温度相对灵敏度约为 0.4 %/K。
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引用次数: 0
Design and preparation of a sintered Nd-Y-Fe-B magnet with high magnetic properties via multi-main-phase process and subsequent grain boundary diffusion 采用多主相法和晶界扩散法制备高磁性能Nd-Y-Fe-B烧结磁体
IF 5.2 1区 化学 Q1 CHEMISTRY, APPLIED Pub Date : 2025-02-01 DOI: 10.1016/j.jre.2023.11.015
Fugang Chen , Suxin Lu , Jie Wang , Yong Zhao , Wenqiang Zhao , Zhi Xu
A sintered Nd-Y-Fe-B magnet was designed and manufactured by the multi-main-phase process. Unevenly distributed Y in the magnet decreases the adverse magnetic weakening effect of Y on the coercivity. Grain boundary diffusion process (GBDP) was conducted to further enhance the coercivity of the Nd-Y-Fe-B magnet. The coercivity increases significantly from 884 to 1741 kA/m after GBDP with Pr60Tb10Cu30 alloy. The mechanism of the coercivity enhancement is discussed based on the microstructure analysis. Micromagnetic simulation reveals that when the diffused Tb-rich shell thickness is lower than 12 nm the c-plane shell (perpendicular to the c-axis) is much more effective in enhancing the coercivity than the side plane shell (parallel to the c-axis). But when the Tb-rich shell thickness is above 12 nm the side plane shell contributes more to the coercivity enhancement. The results in this work can help to design and manufacture Nd-Fe-B magnets with low cost and high magnetic properties.
采用多主相法设计并制备了钕铁硼烧结磁体。磁体中不均匀分布的Y减小了Y对矫顽力的不利弱磁作用。通过晶界扩散过程(GBDP)进一步提高钕铁硼磁体的矫顽力。Pr60Tb10Cu30合金经GBDP后矫顽力由884 kA/m显著提高到1741 kA/m。在微观组织分析的基础上,探讨了矫顽力增强的机理。微磁模拟结果表明,当扩散富铽壳层厚度小于12 nm时,垂直于c轴的c面壳层比平行于c轴的侧面壳层对矫顽力的增强更有效。而当富铽壳层厚度大于12 nm时,侧面壳层对矫顽力的增强作用更大。研究结果有助于设计和制造低成本、高磁性能的钕铁硼磁体。
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引用次数: 0
Alumina supported platinum-ceria catalyst for reverse water gas shift reaction 氧化铝支撑的铂铈催化剂用于反向水煤气变换反应
IF 5.2 1区 化学 Q1 CHEMISTRY, APPLIED Pub Date : 2025-02-01 DOI: 10.1016/j.jre.2024.02.015
Na Jiang, Weiwei Wang, Haoxin Liu, Meiyao Wu, Chunjiang Jia
The activation of CO2 molecules is a fundamental step for their effective utilization. Constructing high-density oxygen vacancies on the surface of reducible oxides is pivotal for the activation of CO2. In this work, we prepared a series of 0.5PtxCe/Al2O3 (x=1, 5, 10, or 20) catalysts with varying Ce loading and 0.5 wt% of Pt for the reverse water gas shift (RWGS) reaction. The size of CeO2 particle increases with Ce loading. Remarkably, the 0.5Pt5Ce/Al2O3 catalyst with an average CeO2 particle size of 5.5 nm exhibits a very high CO2 conversion rate (116.4×10−5 molCO2/(gcat·s)) and CO selectivity (96.1%) at 600 °C. Our experimental findings reveal that the small-size CeO2 in 0.5Pt5Ce/Al2O3 possesses a greater capacity to generate reactive oxygen vacancies, promoting the adsorption and activation of CO2. In addition, the oxygen vacancies are cyclically generated and consumed during the reaction, which contributes to the elevated catalytic performance of the catalyst. This work provides a general strategy to construct rich oxygen vacancies on CeO2 for designing high-performance catalysts in C1 chemistry.
一氧化碳分子的活化是其有效利用的基本步骤。在可还原氧化物表面构建高密度氧空位是活化 CO 的关键。在这项工作中,我们制备了一系列 0.5PtCe/AlO ( = 1、5、10 或 20) 催化剂,这些催化剂中 Ce 的含量和 0.5 wt% 的 Pt 的含量各不相同,用于反向水煤气变换(RWGS)反应。CeO 颗粒的尺寸随 Ce 用量的增加而增大。值得注意的是,平均 CeO 粒径为 5.5 nm 的 0.5Pt5Ce/AlO 催化剂在 600 °C 时表现出极高的 CO 转化率(116.4 × 10 mol/(g-s))和 CO 选择性(96.1%)。我们的实验结果表明,0.5Pt5Ce/AlO 中的小尺寸 CeO 具有更强的生成活性氧空位的能力,从而促进了 CO 的吸附和活化。此外,氧空位在反应过程中循环生成和消耗,这有助于提高催化剂的催化性能。这项工作提供了一种在 CeO 上构建富氧空位的通用策略,用于设计高性能的 C 化学催化剂。
{"title":"Alumina supported platinum-ceria catalyst for reverse water gas shift reaction","authors":"Na Jiang,&nbsp;Weiwei Wang,&nbsp;Haoxin Liu,&nbsp;Meiyao Wu,&nbsp;Chunjiang Jia","doi":"10.1016/j.jre.2024.02.015","DOIUrl":"10.1016/j.jre.2024.02.015","url":null,"abstract":"<div><div>The activation of CO<sub>2</sub> molecules is a fundamental step for their effective utilization. Constructing high-density oxygen vacancies on the surface of reducible oxides is pivotal for the activation of CO<sub>2</sub>. In this work, we prepared a series of 0.5Pt<em>x</em>Ce/Al<sub>2</sub>O<sub>3</sub> (<em>x</em>=1, 5, 10, or 20) catalysts with varying Ce loading and 0.5 wt% of Pt for the reverse water gas shift (RWGS) reaction. The size of CeO<sub>2</sub> particle increases with Ce loading. Remarkably, the 0.5Pt5Ce/Al<sub>2</sub>O<sub>3</sub> catalyst with an average CeO<sub>2</sub> particle size of 5.5 nm exhibits a very high CO<sub>2</sub> conversion rate (116.4×10<sup>−5</sup> mol<sub>CO2</sub>/(g<sub>cat</sub>·s)) and CO selectivity (96.1%) at 600 °C. Our experimental findings reveal that the small-size CeO<sub>2</sub> in 0.5Pt5Ce/Al<sub>2</sub>O<sub>3</sub> possesses a greater capacity to generate reactive oxygen vacancies, promoting the adsorption and activation of CO<sub>2</sub>. In addition, the oxygen vacancies are cyclically generated and consumed during the reaction, which contributes to the elevated catalytic performance of the catalyst. This work provides a general strategy to construct rich oxygen vacancies on CeO<sub>2</sub> for designing high-performance catalysts in C<sub>1</sub> chemistry.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 2","pages":"Pages 284-294"},"PeriodicalIF":5.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140046232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Influence of minor cerium addition on microstructure and fluidity of as-cast Al-Cu-Mn-Mg alloy 少量添加铈对铸造铝-铜-锰-镁合金微观结构和流动性的影响
IF 5.2 1区 化学 Q1 CHEMISTRY, APPLIED Pub Date : 2025-02-01 DOI: 10.1016/j.jre.2024.04.020
Yishan Wang , Yu Bai , Kaixi Jiang , Wenxue Fan , Puxuan Wang , Hai Hao
Al-Cu-Mn alloys are widely used to produce automobile components like cylinder heads and engine blocks because of their capability to retain excellent thermal and mechanical characteristics at high temperatures. However, the Al-Cu-Mn-based alloys demonstrate restricted fluidity, leading to casting defects such as shrinkage and incomplete filling. This research investigated the microstructure and fluidity of Al-4.7Cu-1.0Mn-0.5Mg (wt%) alloy with minor cerium (Ce) addition. The as-cast alloys predominantly comprise α-Al matrix, accompanied by the presence of Al2Cu, Al6Mn, and Al8Cu4Ce phases. The influence of adding Ce on the fluidity of the Al-4.7Cu-1.0Mn-0.5Mg alloy was investigated using a tri-spiral fluidity test mold in this research. The findings suggest that the addition of Ce within the range of 0.1 wt% to 0.5 wt% in the Al-4.7Cu-1.0Mn-0.5Mg alloy results in an enhancement in fluidity. Specifically, the alloy containing 0.4 wt% Ce exhibits a significant increase in fluidity distance, from 349.7 to 485.7 mm. This improvement can be attributed to the reduction in viscosity, the refinement of secondary dendrite arm spacing, and the modification of secondary phase particles. However, a higher concentration of Ce leads to a decrease in fluidity length, potentially due to the formation of Al8Cu4Ce.
{"title":"Influence of minor cerium addition on microstructure and fluidity of as-cast Al-Cu-Mn-Mg alloy","authors":"Yishan Wang ,&nbsp;Yu Bai ,&nbsp;Kaixi Jiang ,&nbsp;Wenxue Fan ,&nbsp;Puxuan Wang ,&nbsp;Hai Hao","doi":"10.1016/j.jre.2024.04.020","DOIUrl":"10.1016/j.jre.2024.04.020","url":null,"abstract":"<div><div>Al-Cu-Mn alloys are widely used to produce automobile components like cylinder heads and engine blocks because of their capability to retain excellent thermal and mechanical characteristics at high temperatures. However, the Al-Cu-Mn-based alloys demonstrate restricted fluidity, leading to casting defects such as shrinkage and incomplete filling. This research investigated the microstructure and fluidity of Al-4.7Cu-1.0Mn-0.5Mg (wt%) alloy with minor cerium (Ce) addition. The as-cast alloys predominantly comprise <em>α</em>-Al matrix, accompanied by the presence of Al<sub>2</sub>Cu, Al<sub>6</sub>Mn, and Al<sub>8</sub>Cu<sub>4</sub>Ce phases. The influence of adding Ce on the fluidity of the Al-4.7Cu-1.0Mn-0.5Mg alloy was investigated using a tri-spiral fluidity test mold in this research. The findings suggest that the addition of Ce within the range of 0.1 wt% to 0.5 wt% in the Al-4.7Cu-1.0Mn-0.5Mg alloy results in an enhancement in fluidity. Specifically, the alloy containing 0.4 wt% Ce exhibits a significant increase in fluidity distance, from 349.7 to 485.7 mm. This improvement can be attributed to the reduction in viscosity, the refinement of secondary dendrite arm spacing, and the modification of secondary phase particles. However, a higher concentration of Ce leads to a decrease in fluidity length, potentially due to the formation of Al<sub>8</sub>Cu<sub>4</sub>Ce.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 2","pages":"Pages 377-383"},"PeriodicalIF":5.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140796437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Characterization and acid leaching of rare earth elements in coal gangue using pretreatment of selective grinding, tailings discarding and alkali roasting 利用选择性研磨、尾矿丢弃和碱焙烧预处理煤矸石中稀土元素的表征和酸浸法
IF 5.2 1区 化学 Q1 CHEMISTRY, APPLIED Pub Date : 2025-02-01 DOI: 10.1016/j.jre.2024.02.018
Xiaorui Wang , Wei Cheng , Ruidong Yang , Jingkun Zang
Co-associated rare earth elements (lanthanide and yttrium, REY) in coal and its by-products have been considered important potential nontraditional rare earth sources. In this study, a coal gangue sample collected from a coal processing plant in Jinsha County of Guizhou Province, southwest China, was used as the research object. The content, modes of occurrence, and extraction (acid leaching after pretreatment of selective grinding, tailings discarding, and alkali roasting) of REY from the sample were analyzed. The result shows that the content of REY (1038.26 μg/g) in pyrite and quartz is low but mainly enriched in kaolinite. Under the following conditions of a filling ratio of 40% (grinding media steel ball) and grinding time of 8 min, selective grinding pretreatment is applied to achieve 176.95 μg/g (yield 24.08%) and 1104.93 μg/g (yield 75.92%) of REY in +2 mm and −2 mm fractions, respectively. Thus, the −2 mm coal gangue fraction is selected, used as the feed, and roasted and leached with HCl. When Na2CO3 and NaCl are separately used as roasting activators, the REY leaching ratios are 91.41% and 68.88%, respectively, under the optimum conditions. The contents of REY in the final leachate are 1010.02 and 761.08 μg/g when Na2CO3 and NaCl are used, respectively. The two REY contents are relatively higher than the impurity ions in the leachate, which facilitates further REY separation. The mechanism study reveals that high-temperature roasting increases the pore size and the total pore area of the gangue, which promotes leachate penetration and improves reaction efficiency. In addition, roasting facilitates the reaction between the sodium salt activator and kaolinite and other aluminosilicate minerals in the coal gangue to generate soluble salts, thus releasing REY into the solution. The appropriate roasting temperature transforms the activator into a molten state. Thus, the reaction between coal gangue and activator is a solid–liquid reaction rather than a solid–solid reaction, which improves the efficiency of the chemical reaction.
{"title":"Characterization and acid leaching of rare earth elements in coal gangue using pretreatment of selective grinding, tailings discarding and alkali roasting","authors":"Xiaorui Wang ,&nbsp;Wei Cheng ,&nbsp;Ruidong Yang ,&nbsp;Jingkun Zang","doi":"10.1016/j.jre.2024.02.018","DOIUrl":"10.1016/j.jre.2024.02.018","url":null,"abstract":"<div><div>Co-associated rare earth elements (lanthanide and yttrium, REY) in coal and its by-products have been considered important potential nontraditional rare earth sources. In this study, a coal gangue sample collected from a coal processing plant in Jinsha County of Guizhou Province, southwest China, was used as the research object. The content, modes of occurrence, and extraction (acid leaching after pretreatment of selective grinding, tailings discarding, and alkali roasting) of REY from the sample were analyzed. The result shows that the content of REY (1038.26 μg/g) in pyrite and quartz is low but mainly enriched in kaolinite. Under the following conditions of a filling ratio of 40% (grinding media steel ball) and grinding time of 8 min, selective grinding pretreatment is applied to achieve 176.95 μg/g (yield 24.08%) and 1104.93 μg/g (yield 75.92%) of REY in +2 mm and −2 mm fractions, respectively. Thus, the −2 mm coal gangue fraction is selected, used as the feed, and roasted and leached with HCl. When Na<sub>2</sub>CO<sub>3</sub> and NaCl are separately used as roasting activators, the REY leaching ratios are 91.41% and 68.88%, respectively, under the optimum conditions. The contents of REY in the final leachate are 1010.02 and 761.08 μg/g when Na<sub>2</sub>CO<sub>3</sub> and NaCl are used, respectively. The two REY contents are relatively higher than the impurity ions in the leachate, which facilitates further REY separation. The mechanism study reveals that high-temperature roasting increases the pore size and the total pore area of the gangue, which promotes leachate penetration and improves reaction efficiency. In addition, roasting facilitates the reaction between the sodium salt activator and kaolinite and other aluminosilicate minerals in the coal gangue to generate soluble salts, thus releasing REY into the solution. The appropriate roasting temperature transforms the activator into a molten state. Thus, the reaction between coal gangue and activator is a solid–liquid reaction rather than a solid–solid reaction, which improves the efficiency of the chemical reaction.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 2","pages":"Pages 384-396"},"PeriodicalIF":5.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140091909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Recent advances of cerium compounds in functional coatings: Principle, strategies and applications 功能涂层中铈化合物的最新进展:原理、策略和应用
IF 5.2 1区 化学 Q1 CHEMISTRY, APPLIED Pub Date : 2025-02-01 DOI: 10.1016/j.jre.2024.03.017
Kai An , Youqiang Wang , Yi Sui , Yongquan Qing , Wei Tong , Xuezhao Wang , Changsheng Liu
Cerium (Ce) compounds have attracted considerable attention as key components in functional coatings due to their many outstanding properties. This work provides a comprehensive review of recent advances in the application of Ce in functional coatings. The role of Ce in the improvement of functional properties such as corrosion-resistance, self-healing, superhydrophobicity, wear-resistance, and UV shielding is reviewed from the perspective of functional mechanism and applied research. Furthermore, the strategies, processes, practical problems, and current challenges in the research of functional coatings containing Ce are summarized and discussed. The objective is to highlight the great potential of Ce in functional coatings, and to explore new applications of Ce in the development of novel coatings. Thus, this work aims to enhance the application value of Ce, solving the problem of unbalanced application of rare-earth elements.
{"title":"Recent advances of cerium compounds in functional coatings: Principle, strategies and applications","authors":"Kai An ,&nbsp;Youqiang Wang ,&nbsp;Yi Sui ,&nbsp;Yongquan Qing ,&nbsp;Wei Tong ,&nbsp;Xuezhao Wang ,&nbsp;Changsheng Liu","doi":"10.1016/j.jre.2024.03.017","DOIUrl":"10.1016/j.jre.2024.03.017","url":null,"abstract":"<div><div>Cerium (Ce) compounds have attracted considerable attention as key components in functional coatings due to their many outstanding properties. This work provides a comprehensive review of recent advances in the application of Ce in functional coatings. The role of Ce in the improvement of functional properties such as corrosion-resistance, self-healing, superhydrophobicity, wear-resistance, and UV shielding is reviewed from the perspective of functional mechanism and applied research. Furthermore, the strategies, processes, practical problems, and current challenges in the research of functional coatings containing Ce are summarized and discussed. The objective is to highlight the great potential of Ce in functional coatings, and to explore new applications of Ce in the development of novel coatings. Thus, this work aims to enhance the application value of Ce, solving the problem of unbalanced application of rare-earth elements.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 2","pages":"Pages 227-245"},"PeriodicalIF":5.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140399976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Comprehensive recovery of rare earth elements and gypsum from phosphogypsum: A wastewater free process combining gravity separation and hydrometallurgy 从磷石膏中全面回收稀土元素和石膏:重力分离与湿法冶金相结合的无废水工艺
IF 5.2 1区 化学 Q1 CHEMISTRY, APPLIED Pub Date : 2025-02-01 DOI: 10.1016/j.jre.2024.01.013
Jialin Qing , Dapeng Zhao , Li Zeng , Guiqing Zhang , Liang Zhou , Jiawei Du , Qinggang Li , Zuoying Cao , Shengxi Wu
Comprehensive utilization of phosphogypsum (PG) has attracted much attention, especially for the recovery of rare earth elements (REEs) and gypsum due to the issues of stockpile, environmental pollution, and waste of associated resources. Traditional utilization methods suffered the issues of low REEs leaching efficiency, huge amount of CaSO4 saturated wastewater and high recovery cost. To solve these issues, this study investigated the occurrence of REEs in PG and the leaching of REEs. The results show that REEs in PG are in the forms of (1) REEs mineral inclusions, (2) REEs isomorphous substitution of Ca2+ in gypsum lattice, (3) dispersed soluble REEs salts. Acid leaching results demonstrate that (1) the dissolution of gypsum matrix is the control factor of REEs leaching; (2) H2SO4 is a promising leachant considering the recycle of leachate; (3) the gypsum matrix suffers a recrystallization during the acid leaching and releases the soluble REEs from PG to aqueous solution. For the recovery of the undissolved REEs mineral inclusions, wet sieving concentrated 37.1 wt% of the REEs in a 10.7 wt% mass, increasing REEs content from 309 to 1071 ppm. Finally, a green process combining gravity separation and hydrometallurgy is proposed. This process owns the merits of wastewater free, considerable REEs recovery (about 10% increase compared with traditional processes), excellent gypsum purification (>95 wt% CaSO4·2H2O, with <0.06 wt% of soluble P2O5 and <0.015 wt% of soluble F) and reagent saving (about 2/3 less reagent consumption than non-cyclical leaching).
磷石膏(PG)的综合利用,尤其是稀土元素(REEs)和石膏的回收利用,因其存在堆存、环境污染和伴生资源浪费等问题而备受关注。传统的利用方法存在稀土元素浸出效率低、CaSO4 饱和废水量大、回收成本高等问题。为了解决这些问题,本研究调查了 REEs 在 PG 中的存在情况以及 REEs 的浸出情况。结果表明,REEs 在 PG 中的存在形式有:(1)REEs 矿物包裹体;(2)REEs 在石膏晶格中对 Ca2+ 的同构取代;(3)分散的可溶性 REEs 盐。酸浸出结果表明:(1)石膏基质的溶解是 REEs 浸出的控制因素;(2)考虑到浸出液的循环利用,H2SO4 是一种很有前途的浸出剂;(3)在酸浸出过程中,石膏基质会发生重结晶,并将可溶性 REEs 从 PG 中释放到水溶液中。为了回收未溶解的 REEs 矿物包裹体,湿筛浓缩了 10.7 重量百分比质量中 37.1 重量百分比的 REEs,将 REEs 含量从 309 ppm 提高到 1071 ppm。最后,提出了一种结合重力分离和湿法冶金的绿色工艺。该工艺具有无废水、REEs 回收率高(与传统工艺相比提高了约 10%)、石膏净化效果好(CaSO4-2H2O 含量为 95 wt%,可溶性 P2O5 含量为 0.06 wt%,可溶性 F 含量为 0.015 wt%)和节省试剂(试剂消耗量比非循环浸出少约 2/3)等优点。
{"title":"Comprehensive recovery of rare earth elements and gypsum from phosphogypsum: A wastewater free process combining gravity separation and hydrometallurgy","authors":"Jialin Qing ,&nbsp;Dapeng Zhao ,&nbsp;Li Zeng ,&nbsp;Guiqing Zhang ,&nbsp;Liang Zhou ,&nbsp;Jiawei Du ,&nbsp;Qinggang Li ,&nbsp;Zuoying Cao ,&nbsp;Shengxi Wu","doi":"10.1016/j.jre.2024.01.013","DOIUrl":"10.1016/j.jre.2024.01.013","url":null,"abstract":"<div><div>Comprehensive utilization of phosphogypsum (PG) has attracted much attention, especially for the recovery of rare earth elements (REEs) and gypsum due to the issues of stockpile, environmental pollution, and waste of associated resources. Traditional utilization methods suffered the issues of low REEs leaching efficiency, huge amount of CaSO<sub>4</sub> saturated wastewater and high recovery cost. To solve these issues, this study investigated the occurrence of REEs in PG and the leaching of REEs. The results show that REEs in PG are in the forms of (1) REEs mineral inclusions, (2) REEs isomorphous substitution of Ca<sup>2+</sup> in gypsum lattice, (3) dispersed soluble REEs salts. Acid leaching results demonstrate that (1) the dissolution of gypsum matrix is the control factor of REEs leaching; (2) H<sub>2</sub>SO<sub>4</sub> is a promising leachant considering the recycle of leachate; (3) the gypsum matrix suffers a recrystallization during the acid leaching and releases the soluble REEs from PG to aqueous solution. For the recovery of the undissolved REEs mineral inclusions, wet sieving concentrated 37.1 wt% of the REEs in a 10.7 wt% mass, increasing REEs content from 309 to 1071 ppm. Finally, a green process combining gravity separation and hydrometallurgy is proposed. This process owns the merits of wastewater free, considerable REEs recovery (about 10% increase compared with traditional processes), excellent gypsum purification (&gt;95 wt% CaSO<sub>4</sub>·2H<sub>2</sub>O, with &lt;0.06 wt% of soluble P<sub>2</sub>O<sub>5</sub> and &lt;0.015 wt% of soluble F) and reagent saving (about 2/3 less reagent consumption than non-cyclical leaching).</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 2","pages":"Pages 362-370"},"PeriodicalIF":5.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139667562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
La3+ substitution-adjusted magnetic and optical properties with enhanced photocatalytic activity and stability of copper zinc nickel ferrites for wastewater treatment applications 用于废水处理的铜锌镍铁氧体的 La3+ 取代调整磁性和光学特性,提高光催化活性和稳定性
IF 5.2 1区 化学 Q1 CHEMISTRY, APPLIED Pub Date : 2025-02-01 DOI: 10.1016/j.jre.2024.03.007
N.S. Al-Bassami
Copper-zinc-nickel (Cu–Zn–Ni) ferrite nanoparticles are used for wastewater treatment technology. However, low degradation efficiency and stability are two main issues that make them unsuitable for actual production needs. In this paper, the citrate-nitrate auto-combustion method was applied for the formation of Cu0.5Zn0.25Ni0.25LaxFe2–xO4; (0≤x≤0.1; step 0.02) (CZNL) nanoferrites. Although the substitution process entails the replacement of a small ion with a larger one, the lattice constant and crystallite size does not exhibit a consistent incremental pattern. This behavior is justified and discussed. The size of all the CZNL ferrite nanoparticles is in the range of 8–12 nm, and the lattice constant is in the range of 8.6230 to 8.4865 nm. The morphological analysis conducted using field emission-scanning electron microscopy (FE-SEM) reveals that the CZNL exhibits agglomerated spherical morphology. The energy dispersive X-ray spectrameter (EDAX) analysis was employed to confirm the elemental composition of CZNL nanoferrites. Since the process entails the substitution of Fe3+ magnetic ions with non-magnetic ions La3+, the magnetic parameters of CZNL nanoferrites show a general decreasing trend as predicted. At 20 K, saturation magnetization Ms shows an overall drop in its values from 59.302 emu/g at x = 0.0–41.295 emu/g at x = 0.1, the smallest value of 37.87 emu/g is recorded at x = 0.06. the highest coercivity (Hc = 125.9 Oe) and remanence (Mr = 13.32 emu/g) are recorded for x = 0.08 and x = 0.04 nanoferrite, respectvely. The band gap of all the CZNL nanoferrites was determined using the Kubelka–Munk function and Tauc plot for direct permitted transitions. La doping modifies the band gap (within 1.86–1.75 eV), increases light absorption, induces efficient e/h separation and charge migration to Cu0.5Zn0.25Ni0.25LaxFe2–xO4 surfaces. The nanoferrite Cu0.5Zn0.25Ni0.25La0.06Fe1.94O4 achieves a degradation efficiency of 97.3% for methylene blue (MB) dye removal after just 60 min. After five recycling processes, the nanocatalyst Cu0.5Zn0.25Ni0.25La0.06Fe1.94O4 is degraded by 95.83%, resulting in a negligible 1.51% decrease in photocatalytic activity efficiency. The new Cu0.5Zn0.25Ni0.25La0.06Fe1.94O4 has exceptional photocatalytic activity and remarkable stability, making it a promising candidate for applications in wastewater treatment.
铜锌镍(Cu-Zn-Ni)铁氧体纳米粒子可用于废水处理技术。然而,降解效率低和稳定性差这两个主要问题使其无法满足实际生产需要。本文采用柠檬酸盐-硝酸盐自燃法形成 CuZnNiLaFeO; (0≤≤0.1; step 0.02) (CZNL) 纳米铁氧体。虽然置换过程需要用较大的离子替换较小的离子,但晶格常数和晶粒大小并没有表现出一致的递增模式。我们对这种行为进行了论证和讨论。所有 CZNL 铁氧体纳米粒子的尺寸都在 8-12 纳米之间,晶格常数在 8.6230 至 8.4865 纳米之间。使用场发射扫描电子显微镜(FE-SEM)进行的形态分析表明,CZNL 呈团聚球形形态。能量色散 X 射线光谱仪(EDAX)分析证实了 CZNL 纳米铁氧体的元素组成。由于在此过程中,非磁性离子 La 取代了铁磁性离子,因此 CZNL 纳米铁氧体的磁性参数呈现出预测的总体下降趋势。在 20 K 时,饱和磁化值从 = 0.0 时的 59.302 emu/g 到 = 0.1 时的 41.295 emu/g,整体呈下降趋势,其中 = 0.06 时的饱和磁化值最小,为 37.87 emu/g。所有 CZNL 纳米铁氧体的带隙都是利用 Kubelka-Munk 函数和 Tauc 图确定的直接允许转变。掺杂 La 改变了带隙(在 1.86-1.75 eV 范围内),增加了光吸收,诱导了有效的 e/h 分离和电荷迁移到 CuZnNiLaFeO 表面。仅用 60 分钟,纳米铁氧体 CuZnNiLaFeO 对亚甲蓝(MB)染料的降解效率就达到了 97.3%。经过五次循环处理后,纳米催化剂 CuZnNiLaFeO 的降解率为 95.83%,光催化活性效率降低了 1.51%,几乎可以忽略不计。新型 CuZnNiLaFeO 具有优异的光催化活性和出色的稳定性,因此有望应用于废水处理。
{"title":"La3+ substitution-adjusted magnetic and optical properties with enhanced photocatalytic activity and stability of copper zinc nickel ferrites for wastewater treatment applications","authors":"N.S. Al-Bassami","doi":"10.1016/j.jre.2024.03.007","DOIUrl":"10.1016/j.jre.2024.03.007","url":null,"abstract":"<div><div>Copper-zinc-nickel (Cu–Zn–Ni) ferrite nanoparticles are used for wastewater treatment technology. However, low degradation efficiency and stability are two main issues that make them unsuitable for actual production needs. In this paper, the citrate-nitrate auto-combustion method was applied for the formation of Cu<sub>0.5</sub>Zn<sub>0.25</sub>Ni<sub>0.25</sub>La<sub><em>x</em></sub>Fe<sub>2–<em>x</em></sub>O<sub>4</sub>; (0≤<em>x</em>≤0.1; step 0.02) (CZNL) nanoferrites. Although the substitution process entails the replacement of a small ion with a larger one, the lattice constant and crystallite size does not exhibit a consistent incremental pattern. This behavior is justified and discussed. The size of all the CZNL ferrite nanoparticles is in the range of 8–12 nm, and the lattice constant is in the range of 8.6230 to 8.4865 nm. The morphological analysis conducted using field emission-scanning electron microscopy (FE-SEM) reveals that the CZNL exhibits agglomerated spherical morphology. The energy dispersive X-ray spectrameter (EDAX) analysis was employed to confirm the elemental composition of CZNL nanoferrites. Since the process entails the substitution of Fe<sup>3+</sup> magnetic ions with non-magnetic ions La<sup>3+</sup>, the magnetic parameters of CZNL nanoferrites show a general decreasing trend as predicted. At 20 K, saturation magnetization <em>M</em><sub>s</sub> shows an overall drop in its values from 59.302 emu/g at <em>x</em> = 0.0–41.295 emu/g at <em>x</em> = 0.1, the smallest value of 37.87 emu/g is recorded at <em>x</em> = 0.06. the highest coercivity (<em>H</em><sub>c</sub> = 125.9 Oe) and remanence (<em>M</em><sub>r</sub> = 13.32 emu/g) are recorded for <em>x</em> = 0.08 and <em>x</em> = 0.04 nanoferrite, respectvely. The band gap of all the CZNL nanoferrites was determined using the Kubelka–Munk function and Tauc plot for direct permitted transitions. La doping modifies the band gap (within 1.86–1.75 eV), increases light absorption, induces efficient e/h separation and charge migration to Cu<sub>0.5</sub>Zn<sub>0.25</sub>Ni<sub>0.25</sub>La<sub><em>x</em></sub>Fe<sub>2–<em>x</em></sub>O<sub>4</sub> surfaces. The nanoferrite Cu<sub>0.5</sub>Zn<sub>0.25</sub>Ni<sub>0.25</sub>La<sub>0.06</sub>Fe<sub>1.94</sub>O<sub>4</sub> achieves a degradation efficiency of 97.3% for methylene blue (MB) dye removal after just 60 min. After five recycling processes, the nanocatalyst Cu<sub>0.5</sub>Zn<sub>0.25</sub>Ni<sub>0.25</sub>La<sub>0.06</sub>Fe<sub>1.94</sub>O<sub>4</sub> is degraded by 95.83%, resulting in a negligible 1.51% decrease in photocatalytic activity efficiency. The new Cu<sub>0.5</sub>Zn<sub>0.25</sub>Ni<sub>0.25</sub>La<sub>0.06</sub>Fe<sub>1.94</sub>O<sub>4</sub> has exceptional photocatalytic activity and remarkable stability, making it a promising candidate for applications in wastewater treatment.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 2","pages":"Pages 319-328"},"PeriodicalIF":5.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140125030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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Journal of Rare Earths
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