Pub Date : 2026-02-01Epub Date: 2025-02-28DOI: 10.1016/j.jre.2025.02.024
Yong Jiang , Qiang Wang , Yaping Du
It is crucial to design highly active, durable, and low precious metal mass-loaded hydrolysis ionization catalysts to promote slow water dissociation for hydrogen production. Herein, a series of armor-like catalyst heterogeneous structures of rare earth (RE) oxide/alloy confined within carbon nanotubes (RuCo/CeO2-NCNTs) was prepared using a one-step pyrolysis phase separation strategy. The prepared catalysts need only overpotentials of 12 and 51 mV for hydrogen evolution reaction (HER) and 141 and 192 mV for oxygen evolution reaction (OER) to achieve a current density of 10 mA/cm2 in 1.0 mol/L KOH and 0.5 mol/L H2SO4 electrolytes. Under alkaline conditions, both HER and OER can work steadily for 1000 h. The turnover frequency (TOF) values of HER and OER are 33.08 s−1 (@100 mV) and 12.75 s−1 (@300 mV) in alkaline environments, respectively. The in situ electrochemical impedance spectroscopy (EIS) test results further confirm that the introduction of cerium oxide optimizes the mass transfer process during the electrochemical process and enhances catalytic activity. The synergistic effect of the RuCo and CeO2 heterostructure confined within NCNTs, combined with the increased conductivity resulting from the expansion of the conductive channels, accelerates reaction kinetics and enhances performance. This study also demonstrates the confinement of RE oxide heterostructures within NCNTs, providing a new solution for the development of novel RE-based catalysts and the high-value utilization of RE.
{"title":"Nitrogen doped carbon nanotube confined rare earth oxide-alloy heterostructure for efficient electrocatalytic water dissociation","authors":"Yong Jiang , Qiang Wang , Yaping Du","doi":"10.1016/j.jre.2025.02.024","DOIUrl":"10.1016/j.jre.2025.02.024","url":null,"abstract":"<div><div>It is crucial to design highly active, durable, and low precious metal mass-loaded hydrolysis ionization catalysts to promote slow water dissociation for hydrogen production. Herein, a series of armor-like catalyst heterogeneous structures of rare earth (RE) oxide/alloy confined within carbon nanotubes (RuCo/CeO<sub>2</sub>-NCNTs) was prepared using a one-step pyrolysis phase separation strategy. The prepared catalysts need only overpotentials of 12 and 51 mV for hydrogen evolution reaction (HER) and 141 and 192 mV for oxygen evolution reaction (OER) to achieve a current density of 10 mA/cm<sup>2</sup> in 1.0 mol/L KOH and 0.5 mol/L H<sub>2</sub>SO<sub>4</sub> electrolytes. Under alkaline conditions, both HER and OER can work steadily for 1000 h. The turnover frequency (TOF) values of HER and OER are 33.08 s<sup>−1</sup> (@100 mV) and 12.75 s<sup>−1</sup> (@300 mV) in alkaline environments, respectively. The <em>in situ</em> electrochemical impedance spectroscopy (EIS) test results further confirm that the introduction of cerium oxide optimizes the mass transfer process during the electrochemical process and enhances catalytic activity. The synergistic effect of the RuCo and CeO<sub>2</sub> heterostructure confined within NCNTs, combined with the increased conductivity resulting from the expansion of the conductive channels, accelerates reaction kinetics and enhances performance. This study also demonstrates the confinement of RE oxide heterostructures within NCNTs, providing a new solution for the development of novel RE-based catalysts and the high-value utilization of RE.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"44 2","pages":"Pages 586-594"},"PeriodicalIF":7.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102714","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 : 2026-02-01Epub Date: 2025-03-19DOI: 10.1016/j.jre.2025.03.019
Jiamin Zhu , Shuhui Li , Yue Zhai , Zejin Lin , Jingzhi Yang , Shanshan Wu , Nan Zhang , Li An , Pinxian Xi , Chun-Hua Yan
The reaction pathway plays a pivotal role in determining the catalytic activity of the oxygen evolution reaction (OER). However, regulating the microscopic reaction pathway through interface construction remains a significant challenge. In this study, an interface between amorphous rare earth hydroxides and crystalline spinel NiCo2O4 was constructed via selective oxidation. The interface structural units accelerate reconstruction, leading to enhanced catalytic activity, which was observed by in situ Raman spectroscopy. The amorphous RE(OH)3 (RE = Y and Eu) optimize asymmetric Ni‒Co dual-sites, thereby altering the OER reaction pathway. Specifically, Y(OH)3/NiCo2O4 operates through the lattice oxygen mechanism (LOM) at the expense of structural stability, whereas Eu(OH)3/NiCo2O4 follows the oxygen pathway mechanism (OPM), preserving both catalytic activity and stability. This study offers a novel approach to controlling reaction pathways and proposes a new strategy for interface construction using rare earth hydroxides.
{"title":"Oxygen radical coupling on asymmetric Ni-Co dual-sites induced by rare earth hydroxides for enhanced alkaline oxygen evolution reaction","authors":"Jiamin Zhu , Shuhui Li , Yue Zhai , Zejin Lin , Jingzhi Yang , Shanshan Wu , Nan Zhang , Li An , Pinxian Xi , Chun-Hua Yan","doi":"10.1016/j.jre.2025.03.019","DOIUrl":"10.1016/j.jre.2025.03.019","url":null,"abstract":"<div><div>The reaction pathway plays a pivotal role in determining the catalytic activity of the oxygen evolution reaction (OER). However, regulating the microscopic reaction pathway through interface construction remains a significant challenge. In this study, an interface between amorphous rare earth hydroxides and crystalline spinel NiCo<sub>2</sub>O<sub>4</sub> was constructed via selective oxidation. The interface structural units accelerate reconstruction, leading to enhanced catalytic activity, which was observed by <em>in situ</em> Raman spectroscopy. The amorphous RE(OH)<sub>3</sub> (RE = Y and Eu) optimize asymmetric Ni‒Co dual-sites, thereby altering the OER reaction pathway. Specifically, Y(OH)<sub>3</sub>/NiCo<sub>2</sub>O<sub>4</sub> operates through the lattice oxygen mechanism (LOM) at the expense of structural stability, whereas Eu(OH)<sub>3</sub>/NiCo<sub>2</sub>O<sub>4</sub> follows the oxygen pathway mechanism (OPM), preserving both catalytic activity and stability. This study offers a novel approach to controlling reaction pathways and proposes a new strategy for interface construction using rare earth hydroxides.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"44 2","pages":"Pages 577-585"},"PeriodicalIF":7.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102713","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 : 2026-02-01Epub Date: 2025-06-24DOI: 10.1016/j.jre.2025.06.014
Biying Tian , Yaqin Chen , Jiawen Sun, Yi-Ru Hao, Chunhao Li, Jing Sun, Hui Xue, Qin Wang
The feasibility of enhancing the electrocatalytic performance of sulfides is demonstrated through element doping and vacancy engineering. However, the investigation on the reaction mechanisms of catalyst doping and defects related to oxygen evolution reaction (OER) still faces significant challenges. In this work, a Ce-doped NiS2 supported on carbon cloth (Ce-NiS2@CC) with abundant sulfur vacancy defects was successfully developed through a sequential two-step hydrothermal and high-temperature vulcanization strategy. The results demonstrate that the obtained Ce-NiS2@CC catalyst exhibits excellent electrochemical performance for both OER and urea oxidation reaction (UOR). It requires only 1.40 and 1.28 V to achieve a current density of 10 mA/cm2 for OER and UOR, respectively. Furthermore, the Tafel slopes observed for OER and UOR are noteworthy at 40.2 and 58.3 mV/dec, respectively, suggesting enhanced kinetics and superior catalytic performance. Additionally, the stability tests conducted on the catalyst reveal that the Ce-NiS2@CC possesses exceptional electrochemical long-term stability, making it a highly reliable and durable option for various applications. Density functional theory calculations and in situ Raman results demonstrate that Ce doping and sulfur vacancy synergistically promote surface reconstruction to form NiⅢ–O species, modulate the local charge distribution near the Ni site, thereby facilitating the adsorption and activation of water molecules, and consequently accelerating the kinetics of OER. This study systematically investigated the impact of metal doping and vacancy defects on electrocatalytic performance, offering insights into electronic structure regulation and performance optimization for efficient electrocatalysts.
{"title":"Vacancy defect-rich NiS2 nanosheets induced by Ce-doping for highly efficient water and urea oxidation reaction","authors":"Biying Tian , Yaqin Chen , Jiawen Sun, Yi-Ru Hao, Chunhao Li, Jing Sun, Hui Xue, Qin Wang","doi":"10.1016/j.jre.2025.06.014","DOIUrl":"10.1016/j.jre.2025.06.014","url":null,"abstract":"<div><div>The feasibility of enhancing the electrocatalytic performance of sulfides is demonstrated through element doping and vacancy engineering. However, the investigation on the reaction mechanisms of catalyst doping and defects related to oxygen evolution reaction (OER) still faces significant challenges. In this work, a Ce-doped NiS<sub>2</sub> supported on carbon cloth (Ce-NiS<sub>2</sub>@CC) with abundant sulfur vacancy defects was successfully developed through a sequential two-step hydrothermal and high-temperature vulcanization strategy. The results demonstrate that the obtained Ce-NiS<sub>2</sub>@CC catalyst exhibits excellent electrochemical performance for both OER and urea oxidation reaction (UOR). It requires only 1.40 and 1.28 V to achieve a current density of 10 mA/cm<sup>2</sup> for OER and UOR, respectively. Furthermore, the Tafel slopes observed for OER and UOR are noteworthy at 40.2 and 58.3 mV/dec, respectively, suggesting enhanced kinetics and superior catalytic performance. Additionally, the stability tests conducted on the catalyst reveal that the Ce-NiS<sub>2</sub>@CC possesses exceptional electrochemical long-term stability, making it a highly reliable and durable option for various applications. Density functional theory calculations and <em>in situ</em> Raman results demonstrate that Ce doping and sulfur vacancy synergistically promote surface reconstruction to form Ni<sup>Ⅲ</sup>–O species, modulate the local charge distribution near the Ni site, thereby facilitating the adsorption and activation of water molecules, and consequently accelerating the kinetics of OER. This study systematically investigated the impact of metal doping and vacancy defects on electrocatalytic performance, offering insights into electronic structure regulation and performance optimization for efficient electrocatalysts.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"44 2","pages":"Pages 604-615"},"PeriodicalIF":7.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102703","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 : 2026-02-01Epub Date: 2025-01-29DOI: 10.1016/j.jre.2025.01.015
Dongyue Cao , Meiwen Tie , Guangrui Zhang , Xiubing Huang
Electrocatalytic water splitting is a sustainable and environmentally friendly approach to hydrogen production, which is regarded as a promising alternative to traditional fossil fuels due to its high energy density and zero pollution. Despite its potential, the efficiency of this process is not yet satisfactory. In recent years, cerium (Ce)-based materials have become popular as electrocatalysts for water splitting, thanks to the variable valence of cerium and the numerous oxygen vacancies present in CeO2. These oxygen vacancies, along with the interface between CeO2 and metal components, can enhance the electronic structure and surface properties, thereby improving the performance of the hydrogen evolution reaction (HER). However, there is still a scarcity of research in this area. This article aims to provide insights into the recent progress made in using cerium for HER by examining different types of catalysts, to guide the design of Ce-based electrocatalysts that exhibit enhanced HER activity.
{"title":"Research progress of Ce-based electrocatalysts in hydrogen evolution reaction","authors":"Dongyue Cao , Meiwen Tie , Guangrui Zhang , Xiubing Huang","doi":"10.1016/j.jre.2025.01.015","DOIUrl":"10.1016/j.jre.2025.01.015","url":null,"abstract":"<div><div>Electrocatalytic water splitting is a sustainable and environmentally friendly approach to hydrogen production, which is regarded as a promising alternative to traditional fossil fuels due to its high energy density and zero pollution. Despite its potential, the efficiency of this process is not yet satisfactory. In recent years, cerium (Ce)-based materials have become popular as electrocatalysts for water splitting, thanks to the variable valence of cerium and the numerous oxygen vacancies present in CeO<sub>2</sub>. These oxygen vacancies, along with the interface between CeO<sub>2</sub> and metal components, can enhance the electronic structure and surface properties, thereby improving the performance of the hydrogen evolution reaction (HER). However, there is still a scarcity of research in this area. This article aims to provide insights into the recent progress made in using cerium for HER by examining different types of catalysts, to guide the design of Ce-based electrocatalysts that exhibit enhanced HER activity.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"44 2","pages":"Pages 450-468"},"PeriodicalIF":7.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102706","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 : 2026-02-01Epub Date: 2025-06-20DOI: 10.1016/j.jre.2025.06.012
Qianwen Liu , Li Wang , Yuyuan Zhao , Xuejiao Hu , Zhihong Yu , Wei Song , Hang Jiang
The advancement of low-loading Pt catalysts for PEMFCs faces challenges such as Pt nanoparticle aggregation, limited electron transfer efficiency, and inadequate stability. To address these challenges, further optimization of the distribution and electron transfer efficiency of Pt nanoparticles can be achieved by incorporating RE, particularly Ce, which enhances the performance and applicability of the ORR catalyst. The uniform distribution of Pt nanoparticles on CeO2 coupled with surface oxygen vacancy enrichment demonstrates that undercoordinated Ce3+ species anchor Pt precursors via oxygen vacancy (OVs), effectively suppressing nanoparticle aggregation and enhancing catalytic stability. This architecture reduces Pt aggregation and improves electron transfer efficiency. The Pt/CeO2@C catalyst exhibits outstanding electrocatalytic performance, attaining an E1/2 of 0.935 V and an electrochemically active surface area (ECSA) of 101.35 m2/g, representing a 25% enhancement over traditional Pt/C catalysts. Density functional theory (DFT) analysis indicates that d-orbital hybridization between CeO2 and Pt reduces the d-band center of Pt, and the introduction of oxygen vacancies enhances oxygen adsorption, offering more active sites for ORR. This breakthrough offers new opportunities for high-performance, cost-efficient fuel cell catalysts, establishing a robust foundation for future large-scale applications in fuel cell technology.
{"title":"Optimizing oxygen reduction reaction: Low-load platinum catalysts anchored on cerium oxide with enhanced electrocatalytic efficiency","authors":"Qianwen Liu , Li Wang , Yuyuan Zhao , Xuejiao Hu , Zhihong Yu , Wei Song , Hang Jiang","doi":"10.1016/j.jre.2025.06.012","DOIUrl":"10.1016/j.jre.2025.06.012","url":null,"abstract":"<div><div>The advancement of low-loading Pt catalysts for PEMFCs faces challenges such as Pt nanoparticle aggregation, limited electron transfer efficiency, and inadequate stability. To address these challenges, further optimization of the distribution and electron transfer efficiency of Pt nanoparticles can be achieved by incorporating RE, particularly Ce, which enhances the performance and applicability of the ORR catalyst. The uniform distribution of Pt nanoparticles on CeO<sub>2</sub> coupled with surface oxygen vacancy enrichment demonstrates that undercoordinated Ce<sup>3+</sup> species anchor Pt precursors via oxygen vacancy (OVs), effectively suppressing nanoparticle aggregation and enhancing catalytic stability. This architecture reduces Pt aggregation and improves electron transfer efficiency. The Pt/CeO<sub>2</sub>@C catalyst exhibits outstanding electrocatalytic performance, attaining an <em>E</em><sub>1/2</sub> of 0.935 V and an electrochemically active surface area (ECSA) of 101.35 m<sup>2</sup>/g, representing a 25% enhancement over traditional Pt/C catalysts. Density functional theory (DFT) analysis indicates that d-orbital hybridization between CeO<sub>2</sub> and Pt reduces the d-band center of Pt, and the introduction of oxygen vacancies enhances oxygen adsorption, offering more active sites for ORR. This breakthrough offers new opportunities for high-performance, cost-efficient fuel cell catalysts, establishing a robust foundation for future large-scale applications in fuel cell technology.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"44 2","pages":"Pages 650-658"},"PeriodicalIF":7.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102780","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 : 2026-02-01Epub Date: 2025-09-12DOI: 10.1016/j.jre.2025.09.019
Yuan Ge, Cuihong Zhang, Qian Wu, Zhenzhen Yu, Zemin He
This research investigated the electrocatalytic properties of a ternary structured dysprosium oxide (Dy2O3)/graphene sheets (Gs)/gadolinium-metal organic frameworks (Gd-MOF) system for oxygen evolution reactions (OER). The ternary Dy2O3/Gs/Gd-MOF composite was synthesised through a simple solvothermal method. The physicochemical properties of all materials were investigated using powder X-ray diffraction (p-XRD), Raman spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, UV-diffuse reflectance spectroscopy (UV-DRS), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetry (TGA) and X-ray photoelectron spectroscopy (XPS). The engineered heterostructure electrodes are fine-tuned to enhance the oxygen evolution reaction (OER) in an alkaline medium using 1.0 mol/L KOH. The ternary Dy2O3/Gs/Gd-MOF composite exhibits a diverse morphology comprising nanosheets, rods, and particle-like features. In contrast to bare and binary electrocatalysts, the ternary Dy2O3/Gs/Gd-MOF electrocatalyst shows superior OER performance and current density due to the successful integration of graphene sheets and Gd-MOF within the Dy2O3 structure. Thus, the ideal ternary Dy2O3/Gs/Gd-MOF shows the minimum overpotential of 339 mV at 50 mA/cm2, a Tafel slope value of 136 mV/dec, and maintains long-standing stability for 24 h at a polarisation current of 50 mA/cm2. The double layer capacitance (Cdl) of the Dy2O3/Gs/Gd-MOF heterostructure (34.69 mF/cm2) surpasses that of the bare and binary electrocatalysts, suggesting that the ternary Dy2O3/Gs/Gd-MOF electrocatalyst possesses a larger electrochemically active surface area. Ultimately, it is shown that the synergetic effect of the Dy2O3/Gs/Gd-MOF electrocatalyst plays a significant role in its remarkable stability during extended OER assessments.
{"title":"Rare-earth metal synergy in Dy2O3/graphene/Gd-MOF ternary structures toward electrocatalytic OER reactions","authors":"Yuan Ge, Cuihong Zhang, Qian Wu, Zhenzhen Yu, Zemin He","doi":"10.1016/j.jre.2025.09.019","DOIUrl":"10.1016/j.jre.2025.09.019","url":null,"abstract":"<div><div>This research investigated the electrocatalytic properties of a ternary structured dysprosium oxide (Dy<sub>2</sub>O<sub>3</sub>)/graphene sheets (Gs)/gadolinium-metal organic frameworks (Gd-MOF) system for oxygen evolution reactions (OER). The ternary Dy<sub>2</sub>O<sub>3</sub>/Gs/Gd-MOF composite was synthesised through a simple solvothermal method. The physicochemical properties of all materials were investigated using powder X-ray diffraction (p-XRD), Raman spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, UV-diffuse reflectance spectroscopy (UV-DRS), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetry (TGA) and X-ray photoelectron spectroscopy (XPS). The engineered heterostructure electrodes are fine-tuned to enhance the oxygen evolution reaction (OER) in an alkaline medium using 1.0 mol/L KOH. The ternary Dy<sub>2</sub>O<sub>3</sub>/Gs/Gd-MOF composite exhibits a diverse morphology comprising nanosheets, rods, and particle-like features. In contrast to bare and binary electrocatalysts, the ternary Dy<sub>2</sub>O<sub>3</sub>/Gs/Gd-MOF electrocatalyst shows superior OER performance and current density due to the successful integration of graphene sheets and Gd-MOF within the Dy<sub>2</sub>O<sub>3</sub> structure. Thus, the ideal ternary Dy<sub>2</sub>O<sub>3</sub>/Gs/Gd-MOF shows the minimum overpotential of 339 mV at 50 mA/cm<sup>2</sup>, a Tafel slope value of 136 mV/dec, and maintains long-standing stability for 24 h at a polarisation current of 50 mA/cm<sup>2</sup>. The double layer capacitance (<em>C</em><sub>dl</sub>) of the Dy<sub>2</sub>O<sub>3</sub>/Gs/Gd-MOF heterostructure (34.69 mF/cm<sup>2</sup>) surpasses that of the bare and binary electrocatalysts, suggesting that the ternary Dy<sub>2</sub>O<sub>3</sub>/Gs/Gd-MOF electrocatalyst possesses a larger electrochemically active surface area. Ultimately, it is shown that the synergetic effect of the Dy<sub>2</sub>O<sub>3</sub>/Gs/Gd-MOF electrocatalyst plays a significant role in its remarkable stability during extended OER assessments.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"44 2","pages":"Pages 630-641"},"PeriodicalIF":7.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102778","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 : 2026-01-01Epub Date: 2025-02-28DOI: 10.1016/j.jre.2025.02.023
Xiangyu Li , Chao Chen , Tao Wang , Zhijie Guo , Hongyu Wang , Haozheng Wang , Liqiang Xue , Jun Tian , Yanhui Sun
<div><div>The magnetic properties of non-oriented silicon steel are affected by the composition and morphology of inclusions in the steel. It is necessary to minimize the number of inclusions and modify the inclusions during the manufacturing process. Rare earth modification of the non-oriented silicon steel is a common practice in steelmaking industry. At present, there is still insufficient research on the properties of rare earth alloys themselves, such as phase composition, inclusions in alloys, and the influence of alloy impurities on inclusions in non-oriented silicon steel. In this paper, the phase composition of Fe-RE-Si alloy was analyzed by X-ray diffraction (XRD) and electron probe microanalysis (EPMA). The inclusions in Fe-RE-Si alloy were analyzed by electrolytic extraction and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) methods. Subsequently, non-oriented silicon steel was melted in a high-temperature tubular resistance furnace and the Fe-RE-Si alloy was added for rare earth treatment. The evolution of inclusions in silicon steel after Fe-RE-Si alloy treatment was studied by thermodynamic calculation and SEM-EDS analysis. The results demonstrate that the Fe-RE-Si alloy is made up of two phases, i.e., the Fe-Si phase and the Ce-Si phase. The inclusions in the alloy are predominately Al-Fe intermetallic compounds and oxide inclusions. The effect of the Fe-RE-Si alloy on the size, morphology and composition of inclusions in non-oriented silicon steel was investigated through high-temperature melting experiments and thermodynamic calculations. The results of experiments show that after treatment with Fe-RE-Si alloy, the rare earth inclusions in non-oriented silicon steel are mainly AlN-RE<sub>2</sub>O<sub>2</sub>S composite inclusions, a small amount of AlN-RES and AlN-REAlO<sub>3</sub> composite inclusions. The modification sequence of rare earth inclusions in heat A (with a rare earth content of 0.0017 wt%) is as follows: RES/RE<sub>2</sub>O<sub>2</sub>S→RE<sub>2</sub>O<sub>2</sub>S/REAlO<sub>3</sub>. Besides, the modification sequence in heat B (with a rare earth content of 0.0119 wt%) is as follows: RE<sub>2</sub>O<sub>3</sub>/RE<sub>2</sub>O<sub>2</sub>S→RES/RE<sub>2</sub>O<sub>2</sub>S. When the rare earth content increases from 0.0017 wt% to 0.0119 wt%, the type of rare earth inclusions changes from RE<sub>2</sub>O<sub>2</sub>S/REAlO<sub>3</sub> to RES/RE<sub>2</sub>O<sub>2</sub>S. The average size of inclusions in two heats increases slightly in 30 min after the addition of Fe-RE-Si alloy. The average size of inclusions in heat A and heat B increases from 1.89 to 2.59 μm, and from 1.93 to 2.6 μm, respectively. The average size of inclusions in the furnace cooling samples of heat A is larger than that of heat B. In both heats, after the addition of Fe-RE-Si alloy, the proportion of inclusions with the size of 0–2 μm decreases and the proportion of inclusions with the size of 2–5 μm increases. The effect
{"title":"Inclusions and phases in Fe-RE-Si steelmaking alloys and their effect on evolution of inclusions in non-oriented silicon steels","authors":"Xiangyu Li , Chao Chen , Tao Wang , Zhijie Guo , Hongyu Wang , Haozheng Wang , Liqiang Xue , Jun Tian , Yanhui Sun","doi":"10.1016/j.jre.2025.02.023","DOIUrl":"10.1016/j.jre.2025.02.023","url":null,"abstract":"<div><div>The magnetic properties of non-oriented silicon steel are affected by the composition and morphology of inclusions in the steel. It is necessary to minimize the number of inclusions and modify the inclusions during the manufacturing process. Rare earth modification of the non-oriented silicon steel is a common practice in steelmaking industry. At present, there is still insufficient research on the properties of rare earth alloys themselves, such as phase composition, inclusions in alloys, and the influence of alloy impurities on inclusions in non-oriented silicon steel. In this paper, the phase composition of Fe-RE-Si alloy was analyzed by X-ray diffraction (XRD) and electron probe microanalysis (EPMA). The inclusions in Fe-RE-Si alloy were analyzed by electrolytic extraction and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) methods. Subsequently, non-oriented silicon steel was melted in a high-temperature tubular resistance furnace and the Fe-RE-Si alloy was added for rare earth treatment. The evolution of inclusions in silicon steel after Fe-RE-Si alloy treatment was studied by thermodynamic calculation and SEM-EDS analysis. The results demonstrate that the Fe-RE-Si alloy is made up of two phases, i.e., the Fe-Si phase and the Ce-Si phase. The inclusions in the alloy are predominately Al-Fe intermetallic compounds and oxide inclusions. The effect of the Fe-RE-Si alloy on the size, morphology and composition of inclusions in non-oriented silicon steel was investigated through high-temperature melting experiments and thermodynamic calculations. The results of experiments show that after treatment with Fe-RE-Si alloy, the rare earth inclusions in non-oriented silicon steel are mainly AlN-RE<sub>2</sub>O<sub>2</sub>S composite inclusions, a small amount of AlN-RES and AlN-REAlO<sub>3</sub> composite inclusions. The modification sequence of rare earth inclusions in heat A (with a rare earth content of 0.0017 wt%) is as follows: RES/RE<sub>2</sub>O<sub>2</sub>S→RE<sub>2</sub>O<sub>2</sub>S/REAlO<sub>3</sub>. Besides, the modification sequence in heat B (with a rare earth content of 0.0119 wt%) is as follows: RE<sub>2</sub>O<sub>3</sub>/RE<sub>2</sub>O<sub>2</sub>S→RES/RE<sub>2</sub>O<sub>2</sub>S. When the rare earth content increases from 0.0017 wt% to 0.0119 wt%, the type of rare earth inclusions changes from RE<sub>2</sub>O<sub>2</sub>S/REAlO<sub>3</sub> to RES/RE<sub>2</sub>O<sub>2</sub>S. The average size of inclusions in two heats increases slightly in 30 min after the addition of Fe-RE-Si alloy. The average size of inclusions in heat A and heat B increases from 1.89 to 2.59 μm, and from 1.93 to 2.6 μm, respectively. The average size of inclusions in the furnace cooling samples of heat A is larger than that of heat B. In both heats, after the addition of Fe-RE-Si alloy, the proportion of inclusions with the size of 0–2 μm decreases and the proportion of inclusions with the size of 2–5 μm increases. The effect ","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"44 1","pages":"Pages 377-387"},"PeriodicalIF":7.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941347","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 : 2026-01-01Epub Date: 2024-12-27DOI: 10.1016/j.jre.2024.12.017
Weiwei Wang , Zhengyao Li , Erdou Li , Weiyao Zhu , Shaochun Hou , Yuanyuan Wang
Heavy rare earth elements (HREEs) have extensive applications in critical industries. Xenotime (YPO4) is an important phosphatic mineral rich in HREEs. The application of 2-hydroxy-3-naphthyl hydroxamic acid (NHA) as a collector in the flotation of xenotime has rarely been been explored previously. This study reveals the effect of NHA on the flotation behavior and adsorption mechanism of xenotime. The high-grade rare earth concentrate with significant recovery is achieved at the optimized flotation conditions. Techniques such as Fourier transform-infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS), and first-principles calculations were employed to clarify the adsorption mechanism of NHA on xenotime. These studies disclose that chemical adsorption occurs through the interaction between N-bonded and carbonyl O atoms, creating a bidentate bond with an Y3+ ion on the xenotime surface. These findings underscore the potential of NHA for selective flotation of xenotime, providing valuable insight into xenotime processing.
{"title":"Flotation separation of xenotime from silicates using 2-hydroxy-3-naphthyl hydroxamic acid collector and its adsorption mechanism: Experimental and first-principles calculations","authors":"Weiwei Wang , Zhengyao Li , Erdou Li , Weiyao Zhu , Shaochun Hou , Yuanyuan Wang","doi":"10.1016/j.jre.2024.12.017","DOIUrl":"10.1016/j.jre.2024.12.017","url":null,"abstract":"<div><div>Heavy rare earth elements (HREEs) have extensive applications in critical industries. Xenotime (YPO<sub>4</sub>) is an important phosphatic mineral rich in HREEs. The application of 2-hydroxy-3-naphthyl hydroxamic acid (NHA) as a collector in the flotation of xenotime has rarely been been explored previously. This study reveals the effect of NHA on the flotation behavior and adsorption mechanism of xenotime. The high-grade rare earth concentrate with significant recovery is achieved at the optimized flotation conditions. Techniques such as Fourier transform-infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS), and first-principles calculations were employed to clarify the adsorption mechanism of NHA on xenotime. These studies disclose that chemical adsorption occurs through the interaction between N-bonded and carbonyl O atoms, creating a bidentate bond with an Y<sup>3+</sup> ion on the xenotime surface. These findings underscore the potential of NHA for selective flotation of xenotime, providing valuable insight into xenotime processing.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"44 1","pages":"Pages 388-397"},"PeriodicalIF":7.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941405","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 : 2026-01-01Epub Date: 2025-01-02DOI: 10.1016/j.jre.2025.01.001
Donglei Wei , Yidi Teng , Xifeng Yang , Yushen Liu , Bo Ram Lee
A comprehensive understanding of the quantity and nature of activator sites is crucial for studying the luminescence performance of phosphors doped with rare earth activators. This research focuses on Eu3+-doped LiAlB2O5, and Eu3+/Si4+ co-doped LiAlB2O5 ceramic phosphors, which were synthesized using a traditional solid-state reaction method. The pure crystalline phase was confirmed by X-ray diffraction (XRD) and Rietveld refinements. The surface characteristics were investigated via scanning electron microscopy (SEM). The luminescence properties such as photoluminescence (PL) spectra, decay curves, CIE color coordinates and quantum efficiency were reported. Site-selective excitation and emission spectra related to the radiative transitions from 7F0 to 5D0 were investigated using a tunable pulsed dye laser (570–590 nm). All samples display a single dominant transition peak at 580.15 nm (17237 cm−1) corresponding to the 7F0 to 5D0 transition, indicating the presence of only one type of Eu3+ center within the lattice. The incorporation of Si4+ alongside Eu3+ in LiAlB2O5 not only significantly enhances red luminescence efficiency but also improves thermal stability. The inhomogeneous disorder surrounding the Eu3+ ions, caused by the excess Si4+ occupying Al3+ sites, results in a notable distortion of the crystal field around the Eu3+ centers. This lattice distortion from the substitution of multiple cations effectively increases both the emission efficiency and thermal activation energy of the Eu3+-doped phosphors. The cation disorder was analyzed through the excitation and luminescence characteristics in the region of the 5D0 to 7F0 transitions. These findings enhance the potential of using Eu3+ as a probe for investigating the microstructure of rare-earth sites in phosphors.
{"title":"Effects of activator site and microstructure on luminescence properties of Eu3+-activated LiAlB2O5 ceramic phosphor","authors":"Donglei Wei , Yidi Teng , Xifeng Yang , Yushen Liu , Bo Ram Lee","doi":"10.1016/j.jre.2025.01.001","DOIUrl":"10.1016/j.jre.2025.01.001","url":null,"abstract":"<div><div>A comprehensive understanding of the quantity and nature of activator sites is crucial for studying the luminescence performance of phosphors doped with rare earth activators. This research focuses on Eu<sup>3+</sup>-doped LiAlB<sub>2</sub>O<sub>5</sub>, and Eu<sup>3+</sup>/Si<sup>4+</sup> co-doped LiAlB<sub>2</sub>O<sub>5</sub> ceramic phosphors, which were synthesized using a traditional solid-state reaction method. The pure crystalline phase was confirmed by X-ray diffraction (XRD) and Rietveld refinements. The surface characteristics were investigated via scanning electron microscopy (SEM). The luminescence properties such as photoluminescence (PL) spectra, decay curves, CIE color coordinates and quantum efficiency were reported. Site-selective excitation and emission spectra related to the radiative transitions from <sup>7</sup>F<sub>0</sub> to <sup>5</sup>D<sub>0</sub> were investigated using a tunable pulsed dye laser (570–590 nm). All samples display a single dominant transition peak at 580.15 nm (17237 cm<sup>−1</sup>) corresponding to the <sup>7</sup>F<sub>0</sub> to <sup>5</sup>D<sub>0</sub> transition, indicating the presence of only one type of Eu<sup>3+</sup> center within the lattice. The incorporation of Si<sup>4+</sup> alongside Eu<sup>3+</sup> in LiAlB<sub>2</sub>O<sub>5</sub> not only significantly enhances red luminescence efficiency but also improves thermal stability. The inhomogeneous disorder surrounding the Eu<sup>3+</sup> ions, caused by the excess Si<sup>4+</sup> occupying Al<sup>3+</sup> sites, results in a notable distortion of the crystal field around the Eu<sup>3+</sup> centers. This lattice distortion from the substitution of multiple cations effectively increases both the emission efficiency and thermal activation energy of the Eu<sup>3+</sup>-doped phosphors. The cation disorder was analyzed through the excitation and luminescence characteristics in the region of the <sup>5</sup>D<sub>0</sub> to <sup>7</sup>F<sub>0</sub> transitions. These findings enhance the potential of using Eu<sup>3+</sup> as a probe for investigating the microstructure of rare-earth sites in phosphors.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"44 1","pages":"Pages 75-84"},"PeriodicalIF":7.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941502","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}
Nanoparticles have emerged as promising agents in the field of cancer therapy due to their unique physicochemical properties owing to their surface functionalization. This study investigated the green synthesis, characterization, and anticancer potential of cerium dioxide nanoparticles (CeO2 NPs) and gadolinium doped cerium dioxide nanoparticles (Gd-doped CeO2 NPs) in human colon cancer (HCT-116) and breast cancer (MCF-7) cell lines. CeO2 and Gd-doped CeO2 NPs were synthesized via sol–gel method using a fruit extract from Acacia Concinna as a surfactant. Their structural, morphological, and physico-chemical properties were characterized using different analytical techniques, like X-ray diffraction (XRD), Raman spectroscopy, UV–visible spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). XRD analysis confirms the cubic fluorite-type structure of CeO2 nanoparticles, with the average crystallite size ranging between 7 and 14 nm. Raman spectroscopy validates this structure with F2g band observed at 462.58 cm−1. FE-SEM images reveal irregular spherical morphologies with grain sizes estimated between 40 and 56 nm. The CeO2 nanoparticles exhibit a prominent absorption peak at 345 nm in the UV–visible spectrum. Increasing the Gd-doping concentration from 2 wt% to 6 wt% results in a rise in the bandgap energy from 2.8 to 3.12 eV. In vitro cytotoxicity assays were performed to evaluate the anticancer efficacy of these nanoparticles. The Gd-doped CeO2 NPs show dose-dependent cytotoxicity, reducing cell viability to 52% and 53% in HCT-116 cells and MCF-7 cells respectively at a concentration of 200 μg/mL, while sparing non-cancerous cell line. The experimental findings suggest the development of CeO2 based promising therapeutic agents and open the avenues for further exploration in the field of cancer nano medicine.
{"title":"Green synthesis and characterization of Gd-doped CeO2 NPs and their anticancer effects against colon cancer and breast cancer","authors":"Sasmita Sarangi , Uday Suryakanta , Nibedita Nayak , Dindyal Mandal , Tapas Ranjan Sahoo","doi":"10.1016/j.jre.2025.02.015","DOIUrl":"10.1016/j.jre.2025.02.015","url":null,"abstract":"<div><div>Nanoparticles have emerged as promising agents in the field of cancer therapy due to their unique physicochemical properties owing to their surface functionalization. This study investigated the green synthesis, characterization, and anticancer potential of cerium dioxide nanoparticles (CeO<sub>2</sub> NPs) and gadolinium doped cerium dioxide nanoparticles (Gd-doped CeO<sub>2</sub> NPs) in human colon cancer (HCT-116) and breast cancer (MCF-7) cell lines. CeO<sub>2</sub> and Gd-doped CeO<sub>2</sub> NPs were synthesized via sol–gel method using a fruit extract from <em>Acacia Concinna</em> as a surfactant. Their structural, morphological, and physico-chemical properties were characterized using different analytical techniques, like X-ray diffraction (XRD), Raman spectroscopy, UV–visible spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). XRD analysis confirms the cubic fluorite-type structure of CeO<sub>2</sub> nanoparticles, with the average crystallite size ranging between 7 and 14 nm. Raman spectroscopy validates this structure with <em>F</em><sub>2g</sub> band observed at 462.58 cm<sup>−1</sup>. FE-SEM images reveal irregular spherical morphologies with grain sizes estimated between 40 and 56 nm. The CeO<sub>2</sub> nanoparticles exhibit a prominent absorption peak at 345 nm in the UV–visible spectrum. Increasing the Gd-doping concentration from 2 wt% to 6 wt% results in a rise in the bandgap energy from 2.8 to 3.12 eV. <em>In vitro</em> cytotoxicity assays were performed to evaluate the anticancer efficacy of these nanoparticles. The Gd-doped CeO<sub>2</sub> NPs show dose-dependent cytotoxicity, reducing cell viability to 52% and 53% in HCT-116 cells and MCF-7 cells respectively at a concentration of 200 μg/mL, while sparing non-cancerous cell line. The experimental findings suggest the development of CeO<sub>2</sub> based promising therapeutic agents and open the avenues for further exploration in the field of cancer nano medicine.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"44 1","pages":"Pages 262-270"},"PeriodicalIF":7.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941489","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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