Pub Date : 2024-02-29DOI: 10.1016/j.jre.2024.02.008
Jianmin Luo , Wenqin Li , Xinglei Wang , Eric Lichtfouse , Donglan Huang , Xiaoyuan Chen , Yi Zhang , Lejie Zhu , Chuanyi Wang
Reactive oxygen species are essential in photocatalytic water treatment. In this paper, Gd doped carbon nitride (CN) photocatalysts were prepared by simple thermal polymerization for the photocatalytic degradation of tetracycline under visible light irradiation. The photodegradation rate of 1.0GdCN is as high as 95% in 18 min, and the photocatalytic performance is much higher than that of CN. The improvement of photocatalytic performance is mainly attributed to the fact that Gd ion implantation directly provides active sites for oxygen activation and induces the formation of N vacancies. The results of characterizations show that the introduction of Gd in CN can improve the conversion ability of activated oxygen, carrier separation and energy band structure adjustment. Therefore, 1.0GdCN photocatalyst can be employed for efficient photocatalytic synthesis of tetracycline. Furthermore, three ways of photocatalytic degradation of tetracycline were revealed by high performance liquid chromatography-mass spectrometry. This work provides insights into the doping strategy of CN to improve the production of reactive oxygen species for environmental remediation.
{"title":"Linker gadolinium as charge channel and singlet oxygen activation site in graphitic carbon nitride for enhancing photocatalytic decomposition of tetracycline","authors":"Jianmin Luo , Wenqin Li , Xinglei Wang , Eric Lichtfouse , Donglan Huang , Xiaoyuan Chen , Yi Zhang , Lejie Zhu , Chuanyi Wang","doi":"10.1016/j.jre.2024.02.008","DOIUrl":"10.1016/j.jre.2024.02.008","url":null,"abstract":"<div><p>Reactive oxygen species are essential in photocatalytic water treatment. In this paper, Gd doped carbon nitride (CN) photocatalysts were prepared by simple thermal polymerization for the photocatalytic degradation of tetracycline under visible light irradiation. The photodegradation rate of 1.0GdCN is as high as 95% in 18 min, and the photocatalytic performance is much higher than that of CN. The improvement of photocatalytic performance is mainly attributed to the fact that Gd ion implantation directly provides active sites for oxygen activation and induces the formation of N vacancies. The results of characterizations show that the introduction of Gd in CN can improve the conversion ability of activated oxygen, carrier separation and energy band structure adjustment. Therefore, 1.0GdCN photocatalyst can be employed for efficient photocatalytic synthesis of tetracycline. Furthermore, three ways of photocatalytic degradation of tetracycline were revealed by high performance liquid chromatography-mass spectrometry. This work provides insights into the doping strategy of CN to improve the production of reactive oxygen species for environmental remediation.</p></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"42 5","pages":"Pages 827-837"},"PeriodicalIF":4.9,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140045962","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}
The acid leaching residue (ALR) of ionic rare earth (IRE) concentrates containing radioactive elements such as thorium (Th) is classified as low-level radioactive waste. ALR holds valuable strategic resources such as rare earth and Th, while improper long-term heaping storage of ALR poses a substantial environmental risk. This paper proposes a comprehensive process involving low-temperature roasting, hydrochloric acid leaching, single extractant enrichment, and stepwise stripping to recover rare earth elements and thorium from ALR. The achieved leaching efficiencies are 80.11% of LnY, 99.43% of Sc(III), and 98.67% of Th(IV) after the carbonization of the organic phase in the ALR through low-temperature roasting. Despite large amounts of acid and impurities present in the leachate, 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester (HEHEHP) still exhibits nearly 100% extraction efficiency for Sc(III) and Th(IV). The effective separation of LnY, Th(IV), and Sc(III) was achieved by implementing fractional extraction enrichment of Th(IV) and Sc(III), followed by Th(IV) removal through HSO and Sc(III) removal via NaOH from the loaded organic phase. This scheme successfully achieves a recovery of RE and Th and offers a viable solution for the safe disposal of ALR.
{"title":"Recovery of rare earth elements and thorium from acid leaching residue of ionic rare earth concentrates","authors":"Qiaofa Lan, Xiaolin Zhang, Fei Niu, Donghui Liu, Leiting Shen, Youming Yang","doi":"10.1016/j.jre.2024.02.010","DOIUrl":"https://doi.org/10.1016/j.jre.2024.02.010","url":null,"abstract":"The acid leaching residue (ALR) of ionic rare earth (IRE) concentrates containing radioactive elements such as thorium (Th) is classified as low-level radioactive waste. ALR holds valuable strategic resources such as rare earth and Th, while improper long-term heaping storage of ALR poses a substantial environmental risk. This paper proposes a comprehensive process involving low-temperature roasting, hydrochloric acid leaching, single extractant enrichment, and stepwise stripping to recover rare earth elements and thorium from ALR. The achieved leaching efficiencies are 80.11% of LnY, 99.43% of Sc(III), and 98.67% of Th(IV) after the carbonization of the organic phase in the ALR through low-temperature roasting. Despite large amounts of acid and impurities present in the leachate, 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester (HEHEHP) still exhibits nearly 100% extraction efficiency for Sc(III) and Th(IV). The effective separation of LnY, Th(IV), and Sc(III) was achieved by implementing fractional extraction enrichment of Th(IV) and Sc(III), followed by Th(IV) removal through HSO and Sc(III) removal via NaOH from the loaded organic phase. This scheme successfully achieves a recovery of RE and Th and offers a viable solution for the safe disposal of ALR.","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"79 1","pages":""},"PeriodicalIF":4.9,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140007841","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}
Pub Date : 2024-02-24DOI: 10.1016/j.jre.2024.02.014
Ibrahim Mohammed, Mohamed E. El Sayed, Ali Shawabkeh, Mohammad N. Murshed, Ibtehaj F. Alshdoukhi, Zeinhom M. El-Bahy, J. Mohammed, A.K. Srivastava
This study was conducted to investigate the properties of Pr-Dy doped ZnY-type hexaferrite for potential technological applications. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FESEM) were used to analyze structural properties. The crystallite size in the synthesized samples varies between 57.54 and 68.57 nm. The vibrational bands at 400 and 600 cm, common to all hexaferrites, were confirmed through FTIR. The FESEM analysis reveals an agglomeration of magnetic grains and a decrease in the average grain size from 1.24 to 1.06 μm. The loops show that, with values of 0.0, 0.1, and 0.2, the saturation magnetization is determined to be 34.76, 34.23, and 32.52 emu/g, respectively. The corresponding coercivity values are 21.24, 30.39, and 33.99 Oe. UV–visible spectroscopy using Tauc theory reveals an increase in the optical band gap from 2.32 to 2.50 eV, indicating a tunable energy band structure by incorporating Pr-Dy ions. The dielectric constant increases, whereas AC conductivity decreases with increased Pr-Dy concentration. The obtained results suggest the potential suitability of these materials for various technological applications.
{"title":"Effects of rare-earth Pr3+-Dy3+ doping on structural, magnetic, optical and dielectric properties of Zn2Y hexaferrite","authors":"Ibrahim Mohammed, Mohamed E. El Sayed, Ali Shawabkeh, Mohammad N. Murshed, Ibtehaj F. Alshdoukhi, Zeinhom M. El-Bahy, J. Mohammed, A.K. Srivastava","doi":"10.1016/j.jre.2024.02.014","DOIUrl":"https://doi.org/10.1016/j.jre.2024.02.014","url":null,"abstract":"This study was conducted to investigate the properties of Pr-Dy doped ZnY-type hexaferrite for potential technological applications. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FESEM) were used to analyze structural properties. The crystallite size in the synthesized samples varies between 57.54 and 68.57 nm. The vibrational bands at 400 and 600 cm, common to all hexaferrites, were confirmed through FTIR. The FESEM analysis reveals an agglomeration of magnetic grains and a decrease in the average grain size from 1.24 to 1.06 μm. The loops show that, with values of 0.0, 0.1, and 0.2, the saturation magnetization is determined to be 34.76, 34.23, and 32.52 emu/g, respectively. The corresponding coercivity values are 21.24, 30.39, and 33.99 Oe. UV–visible spectroscopy using Tauc theory reveals an increase in the optical band gap from 2.32 to 2.50 eV, indicating a tunable energy band structure by incorporating Pr-Dy ions. The dielectric constant increases, whereas AC conductivity decreases with increased Pr-Dy concentration. The obtained results suggest the potential suitability of these materials for various technological applications.","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"8 1","pages":""},"PeriodicalIF":4.9,"publicationDate":"2024-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140007839","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}
Pub Date : 2024-02-24DOI: 10.1016/j.jre.2024.02.012
Yufeng Tong, Yunyun Li, Qingsong Song, Jie Xu, Xiaodong Xu, Mikhail Korzhik, Jun Xu, Kheirreddine Lebbou, Yuntao Wu
In this study, we aim to clarify the luminescence and scintillation performance of 0.2 at%Pr-doped LuYAG scintillators with either zirconium or hafnium co-doping obtained using the micro-pulling-down (-PD) method. Under radiation excitation, scintillation properties such as light yield, decay time, and afterglow level were measured and compared to non-co-doped LuYAG:Pr. The positive effect of Zr and Hf co-doping is to significantly shorten the scintillation time response. The negative effect is the decrease of scintillation yield and increase of afterglow. We propose that the positively charged defects induced by Zr/Hf co-doping are responsible for the spatial correlated traps around Pr centers causing the shortened scintillation decay via non-radiative recombination processes, and the deep traps as well for the prolonged afterglow.
{"title":"Effects of Zr4+ and Hf4+ co-doping on luminescence and scintillation properties of LuYAG:Pr3+ single crystals grown by micro-pulling-down technique","authors":"Yufeng Tong, Yunyun Li, Qingsong Song, Jie Xu, Xiaodong Xu, Mikhail Korzhik, Jun Xu, Kheirreddine Lebbou, Yuntao Wu","doi":"10.1016/j.jre.2024.02.012","DOIUrl":"https://doi.org/10.1016/j.jre.2024.02.012","url":null,"abstract":"In this study, we aim to clarify the luminescence and scintillation performance of 0.2 at%Pr-doped LuYAG scintillators with either zirconium or hafnium co-doping obtained using the micro-pulling-down (-PD) method. Under radiation excitation, scintillation properties such as light yield, decay time, and afterglow level were measured and compared to non-co-doped LuYAG:Pr. The positive effect of Zr and Hf co-doping is to significantly shorten the scintillation time response. The negative effect is the decrease of scintillation yield and increase of afterglow. We propose that the positively charged defects induced by Zr/Hf co-doping are responsible for the spatial correlated traps around Pr centers causing the shortened scintillation decay via non-radiative recombination processes, and the deep traps as well for the prolonged afterglow.","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"19 1","pages":""},"PeriodicalIF":4.9,"publicationDate":"2024-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140007812","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}
Pub Date : 2024-02-20DOI: 10.1016/j.jre.2024.02.011
San'gen Luo, Munan Yang, Shuwei Zhong, Sajjad Ur Rehman, Jiajie Li, Xiaoqiang Yu, Bin Yang
{"title":"Utility and influence mechanism of densification modulation on grain boundary diffusion in NdFeB magnets","authors":"San'gen Luo, Munan Yang, Shuwei Zhong, Sajjad Ur Rehman, Jiajie Li, Xiaoqiang Yu, Bin Yang","doi":"10.1016/j.jre.2024.02.011","DOIUrl":"https://doi.org/10.1016/j.jre.2024.02.011","url":null,"abstract":"","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"46 1","pages":""},"PeriodicalIF":4.9,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139926513","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}
Pub Date : 2024-02-08DOI: 10.1016/j.jre.2024.01.014
The tumor microenvironment (TME) differs from normal tissue cells in its physiological and biochemical characteristics. The construction of TME-responsive nanoplatforms requires a tedious preparation process and complex multicomponent modification. In this work, Er@EGCG-Cu, a TME-responsive nanoplatform, was simply and rapidly synthesized by combining rare earth-doped nanomaterials (NaLuF4:Yb,Er) with EGCG-Cu which is based on the ability of metal ions to coordinate with polyphenols to form a metal-phenolic network (MPN) structure. The MPN structure is then destroyed under an acidic TME, releasing the chemotherapy (CT) drug EGCG, which can cause apoptosis. CuxSy is generated by combining Cu2+ with H2S overexpressed in human colorectal cancer cells and can be used for photothermal therapy (PTT). Cell experiments show that laser irradiation improves the CT/PTT synergistic effect of Er@EGCG-Cu. This study has significance for the construction of TME-responsive nanomedicines with simple and rapid preparation for synergistic therapy.
{"title":"Facile synthesis of a tumor microenvironment-responsive nanomaterial with metallic polyphenol-encapsulated for enhanced synergistic therapy","authors":"","doi":"10.1016/j.jre.2024.01.014","DOIUrl":"10.1016/j.jre.2024.01.014","url":null,"abstract":"<div><div>The tumor microenvironment (TME) differs from normal tissue cells in its physiological and biochemical characteristics. The construction of TME-responsive nanoplatforms requires a tedious preparation process and complex multicomponent modification. In this work, Er@EGCG-Cu, a TME-responsive nanoplatform, was simply and rapidly synthesized by combining rare earth-doped nanomaterials (NaLuF<sub>4</sub>:Yb,Er) with EGCG-Cu which is based on the ability of metal ions to coordinate with polyphenols to form a metal-phenolic network (MPN) structure. The MPN structure is then destroyed under an acidic TME, releasing the chemotherapy (CT) drug EGCG, which can cause apoptosis. Cu<sub><em>x</em></sub>S<sub><em>y</em></sub> is generated by combining Cu<sup>2+</sup> with H<sub>2</sub>S overexpressed in human colorectal cancer cells and can be used for photothermal therapy (PTT). Cell experiments show that laser irradiation improves the CT/PTT synergistic effect of Er@EGCG-Cu. This study has significance for the construction of TME-responsive nanomedicines with simple and rapid preparation for synergistic therapy.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"42 10","pages":"Pages 1895-1902"},"PeriodicalIF":5.2,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139828810","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}
Pub Date : 2024-02-06DOI: 10.1016/j.jre.2024.01.017
Lanthanum-doped double halide perovskite has attracted increasing interest due to its distinctive up-conversion and near-infrared (NIR) luminous characteristics. Here, erbium ion (Er3+) doped Cs2(Na/Ag)BiCl6 microcrystals (MCs) were synthesized and proved to be one of the most prospective candidates for optical thermometry. The enhancement of both white light from self-trapped exciton emission and NIR emission from Er3+ ion of Cs2AgBiCl6 microcrystals is caused by lattice distortion due to Na+ ion doping. Fluorescence intensity ratio and lifetime methods provide self-referenced and sensitive thermometry under 405 and/or 980 nm laser excitation at the temperatures from 80 to 480 K. Besides, the maximum values of relative and absolute sensitivity of 3.62%/K and 27%/K can be achieved in the low to high temperature range under 980 and 405 nm laser co-excitation. Through the experimental analysis, Er3+ doped Cs2(Na/Ag)BiCl6 double perovskite is considered to be an ideal self-calibrating thermometric material due to its good long-term stability and multi-mode function of excitation and detection.
{"title":"Luminescent enhancement and multi-mode optical thermometry of erbium doped halide Cs2(Na/Ag)BiCl6 microcrystals","authors":"","doi":"10.1016/j.jre.2024.01.017","DOIUrl":"10.1016/j.jre.2024.01.017","url":null,"abstract":"<div><div>Lanthanum-doped double halide perovskite has attracted increasing interest due to its distinctive up-conversion and near-infrared (NIR) luminous characteristics. Here, erbium ion (Er<sup>3+</sup>) doped Cs<sub>2</sub>(Na/Ag)BiCl<sub>6</sub> microcrystals (MCs) were synthesized and proved to be one of the most prospective candidates for optical thermometry. The enhancement of both white light from self-trapped exciton emission and NIR emission from Er<sup>3+</sup> ion of Cs<sub>2</sub>AgBiCl<sub>6</sub> microcrystals is caused by lattice distortion due to Na<sup>+</sup> ion doping. Fluorescence intensity ratio and lifetime methods provide self-referenced and sensitive thermometry under 405 and/or 980 nm laser excitation at the temperatures from 80 to 480 K. Besides, the maximum values of relative and absolute sensitivity of 3.62%/K and 27%/K can be achieved in the low to high temperature range under 980 and 405 nm laser co-excitation. Through the experimental analysis, Er<sup>3+</sup> doped Cs<sub>2</sub>(Na/Ag)BiCl<sub>6</sub> double perovskite is considered to be an ideal self-calibrating thermometric material due to its good long-term stability and multi-mode function of excitation and detection.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"42 11","pages":"Pages 2018-2026"},"PeriodicalIF":5.2,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139820235","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}
Pub Date : 2024-02-05DOI: 10.1016/j.jre.2024.02.003
Xincong He , Huazhou Hu , Ruizhu Tang , Wenhao Zhou , Houqun Xiao , Xiaoxuan Zhang , Chuanming Ma , Qingjun Chen
Superlattice hydrogen storage alloys offer a compelling advantage with rapid hydriding rate and high storage capacity. However, its practical applications face challenges including complex structure, low dehydriding capacity, and cyclic instability. In this work, we successfully prepared La0.66Mg0.34Ni3.5–xCox superlattice hydrogen storage alloys with enhanced dehydriding capacity and stability by partially substituting Co for Ni. X-ray diffraction (XRD) refinements analysis reveals the presence of (La,Mg)3Ni9, (La,Mg)5Ni19, and LaNi5 phases within the alloy. Following Co substitution in the La0.66Mg0.34Ni3.4Co0.1 alloy, there is a significant increase in content of the (La, Mg)3Ni9 phase and a reduction in the hysteresis factor, resulting in an improved reversible hydrogen storage capacity from 1.45 wt% to 1.60 wt%. The dehydriding kinetics of the alloy is controlled by diffusion model with an activation energy of 8.40 kJ/mol. Furthermore, the dehydriding enthalpy value of the Co-substituted alloy decreases from 30.84 to 29.85 kJ/mol. Impressively, the cycling performance of the alloy after Co substitution exhibits excellent stability, with a capacity retention rate of 92.3% after 100 cycles. These findings provide valuable insights for the development of cost-effective hydrogen storage materials.
{"title":"Effect of cobalt substitution for nickel on microstructural evolution and hydrogen storage properties of La0.66Mg0.34Ni3.5–xCox alloys","authors":"Xincong He , Huazhou Hu , Ruizhu Tang , Wenhao Zhou , Houqun Xiao , Xiaoxuan Zhang , Chuanming Ma , Qingjun Chen","doi":"10.1016/j.jre.2024.02.003","DOIUrl":"10.1016/j.jre.2024.02.003","url":null,"abstract":"<div><p>Superlattice hydrogen storage alloys offer a compelling advantage with rapid hydriding rate and high storage capacity. However, its practical applications face challenges including complex structure, low dehydriding capacity, and cyclic instability. In this work, we successfully prepared La<sub>0.66</sub>Mg<sub>0.34</sub>Ni<sub>3.5–<em>x</em></sub>Co<sub><em>x</em></sub> superlattice hydrogen storage alloys with enhanced dehydriding capacity and stability by partially substituting Co for Ni. X-ray diffraction (XRD) refinements analysis reveals the presence of (La,Mg)<sub>3</sub>Ni<sub>9</sub>, (La,Mg)<sub>5</sub>Ni<sub>19</sub>, and LaNi<sub>5</sub> phases within the alloy. Following Co substitution in the La<sub>0.66</sub>Mg<sub>0.34</sub>Ni<sub>3.4</sub>Co<sub>0.1</sub> alloy, there is a significant increase in content of the (La, Mg)<sub>3</sub>Ni<sub>9</sub> phase and a reduction in the hysteresis factor, resulting in an improved reversible hydrogen storage capacity from 1.45 wt% to 1.60 wt%. The dehydriding kinetics of the alloy is controlled by diffusion model with an activation energy of 8.40 kJ/mol. Furthermore, the dehydriding enthalpy value of the Co-substituted alloy decreases from 30.84 to 29.85 kJ/mol. Impressively, the cycling performance of the alloy after Co substitution exhibits excellent stability, with a capacity retention rate of 92.3% after 100 cycles. These findings provide valuable insights for the development of cost-effective hydrogen storage materials.</p></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"42 5","pages":"Pages 930-939"},"PeriodicalIF":4.9,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139689846","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}
Pub Date : 2024-02-05DOI: 10.1016/j.jre.2024.02.001
Xuan Xu, Xiaozheng Jia, Peng Jing, Yuanyuan Zhang, Jianguo Cui, Kristina Zuzek, Sturm Saso, Baocang Liu, Jun Zhang
Neodymium-iron-boron (Nd-Fe-B) sludge is an important secondary resource of rare-earth elements (REEs). However, the state-of-the-art recycling method, i.e., HCl-preferential dissolution faces challenges such as slow leaching kinetics, excessive chemical consumption and wastewater generation. In this work, the in situ anodic leaching of Nd-Fe-B sludge was developed to selectively recover REEs with high efficiency. The leaching rates of the REEs are 2.4–9.0 times higher using the in situ anodic leaching at the current density from 10 to 40 mA/cm2 than using conventional chemical leaching under the maintained pH of 3.7. Mechanism studies reveal that the anode-generated H+ plays the key role during the in situ anodic leaching process that locally increases the H+ concentration at the interface of sludge particles, accelerating the leaching kinetics. By achieving a total leaching efficiency of Nd-Fe-B sludge close to 100% and the Fe deposition efficiency in the range of 70.9%–74.3%, selective leaching of REEs is successfully realized and thus largely reduces chemical consumption. Additionally, a two-step recycling route involving electrolysis-selective precipitation was proposed that enables a stable REEs recovery of 92.2% with recyclable electrolyte. This study provides a novel and environmentally-friendly strategy for the efficient recovery of REEs from secondary resources.
{"title":"In situ anodic leaching of Nd-Fe-B sludge with fast leaching kinetics for selective recovery of rare-earth elements","authors":"Xuan Xu, Xiaozheng Jia, Peng Jing, Yuanyuan Zhang, Jianguo Cui, Kristina Zuzek, Sturm Saso, Baocang Liu, Jun Zhang","doi":"10.1016/j.jre.2024.02.001","DOIUrl":"https://doi.org/10.1016/j.jre.2024.02.001","url":null,"abstract":"<p>Neodymium-iron-boron (Nd-Fe-B) sludge is an important secondary resource of rare-earth elements (REEs). However, the state-of-the-art recycling method, i.e., HCl-preferential dissolution faces challenges such as slow leaching kinetics, excessive chemical consumption and wastewater generation. In this work, the <em>in situ</em> anodic leaching of Nd-Fe-B sludge was developed to selectively recover REEs with high efficiency. The leaching rates of the REEs are 2.4–9.0 times higher using the <em>in situ</em> anodic leaching at the current density from 10 to 40 mA/cm<sup>2</sup> than using conventional chemical leaching under the maintained pH of 3.7. Mechanism studies reveal that the anode-generated H<sup>+</sup> plays the key role during the <em>in situ</em> anodic leaching process that locally increases the H<sup>+</sup> concentration at the interface of sludge particles, accelerating the leaching kinetics. By achieving a total leaching efficiency of Nd-Fe-B sludge close to 100% and the Fe deposition efficiency in the range of 70.9%–74.3%, selective leaching of REEs is successfully realized and thus largely reduces chemical consumption. Additionally, a two-step recycling route involving electrolysis-selective precipitation was proposed that enables a stable REEs recovery of 92.2% with recyclable electrolyte. This study provides a novel and environmentally-friendly strategy for the efficient recovery of REEs from secondary resources.</p>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"162 1","pages":""},"PeriodicalIF":4.9,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139690019","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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