Rare Metals最新文献

{"title":"Nanofullerene regulated electric field to achieve stable Sn metal anode for aqueous Sn batteries","authors":"Yi Wang,&nbsp;Neng-Ze Wang,&nbsp;Zi-Ang Wu,&nbsp;Jia Liu,&nbsp;Kai-Lin Guan,&nbsp;Zi-Long Zhang,&nbsp;Hou-Zhao Wan,&nbsp;Hao Wang,&nbsp;Dong-Yang Sun,&nbsp;An Xie","doi":"10.1007/s12598-024-02971-8","DOIUrl":"10.1007/s12598-024-02971-8","url":null,"abstract":"<div><p>Metallic Tin (Sn) is an attractive anode material for aqueous batteries due to its high theoretical capacity, low redox potential and strong corrosion resistance. However, the uneven deposition of Sn and severe interfacial side reactions limit its wide application. Herein, a nanoscale fullerene (C₆₀) coating on a Sn anode has been developed by the physical evaporation deposition technology to eliminate complicated side reactions. This coating improves the homogeneity of the Sn anode surface electric field, and reduces the formation of \"dead tin\". As a result, the C₆₀-coated Sn anode can maintain a low voltage hysteresis cycle for more than 850 h. The aqueous NiO//Sn cell encapsulated by this anode achieves a maximum specific discharge capacity of 79.3 mAh·g⁻¹ at a current density of 1.5 A·g⁻¹. Moreover, as a proof of concept, we propose an aqueous electrochromic Sn battery, which can realize energy storage and reversibly color switch, yielding favorable optical modulation of about 61.1% at 523 nm. This work has developed a cost-effective and high-reliability interfacial engineering strategy that boosts practical uses of Sn metal electrodes, as well as promotes the application of innovative aqueous rechargeable batteries with electrochromic properties.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 6","pages":"3869 - 3880"},"PeriodicalIF":9.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solvent extraction systems for selective isolation of light rare earth elements with high selectivity for Sm and La","authors":"Hossein Salehi,&nbsp;Samane Maroufi,&nbsp;Rasoul Khayyam Nekouei,&nbsp;Veena Sahajwalla","doi":"10.1007/s12598-024-03019-7","DOIUrl":"10.1007/s12598-024-03019-7","url":null,"abstract":"<div><p>This study details a comprehensive approach focusing on the effective separation of light rare earth elements (REEs) via solvent extraction technique. A stock solution containing lanthanum, cerium, neodymium, praseodymium, and samarium was prepared by dissolving their pure mixed oxide (reclaimed from spent Ni-MH batteries) in a diluted HCl solution. Key extractants, including bis (2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272), Cyanex 572, trialkylphosphine oxide (Cyanex 923), and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC 88A), along with tributyl phosphate (TBP) as a phase modifier, were utilized to form organic systems. The extraction behavior and separability of these systems at various pH levels as well as their extraction mechanisms were investigated. The results demonstrated a direct relationship between the extraction trend and the experimental pH value, with enhanced selectivity when TBP was added. Notably, Nd and Pr exhibited similar extraction behaviors, with minor deviations from Ce, making their separation difficult to achieve. Sm extraction followed a distinct trend, allowing for its separation from other elements at pH ≤ 2. In contrast, La exhibited a low affinity for coordination with extractants when pH was ≤ 3.5, facilitating the separation of other elements from La, which could then be isolated in the raffinate. Among the studied organic systems, combinations of Cyanex 572 and PC 88A with TBP demonstrated superior performance in element separation. Optimum separation factors were calculated with <i>β</i>_Ce/La = 12, <i>β</i>_Nd/La = 87, <i>β</i>_Pr/La = 127, and <i>β</i>_Sm/La = 3191 for the former, and <i>β</i>_Sm/Ce = 54, <i>β</i>_Sm/Nd = 20, and <i>β</i>_Sm/Pr = 14 for the latter. These findings provide valuable insights for selecting extraction systems and designing experiments for the effective solvent extraction separation of light REEs from their mixture.</p><h3>Graphic Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 3","pages":"2071 - 2084"},"PeriodicalIF":9.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12598-024-03019-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143667901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resource sustainability application of lithium iron phosphate batteries via citric acid coupled recycling and regeneration","authors":"Xiang Li,&nbsp;Gui-Dong Li,&nbsp;Ye Chen,&nbsp;Meng-Kui Tian","doi":"10.1007/s12598-024-03113-w","DOIUrl":"10.1007/s12598-024-03113-w","url":null,"abstract":"<div><p>Lithium iron phosphate (LiFePO₄, LFP) batteries have shown extensive adoption in power applications in recent years for their reliable safety, high theoretical capability and low cost. Nevertheless, the finite lifespan of these batteries necessitates the future processing of a significant number of spent LFP batteries, underscoring the urgent need for the development of both efficient and eco-friendly recycling methods. This study combines the advantages of wet leaching and direct regeneration methods, leveraging citric acid’s multifaceted role to streamline the combined leaching and hydrothermal processes. Results indicate that citric acid efficiently leaches all elements from spent LFP batteries. Furthermore, through its unique structure, it enhances hydrothermal regeneration by stabilizing metal ions and controlling crystal growth, and also acts as a carbon source for the surface carbon coating of regenerated LFP (R-LFP). The R-LFP shows outstanding electrochemical stability, achieving a discharge capacity of 155.1 mAh·g⁻¹ at 0.1C, with a capacity retention rate of 93.2% after 300 cycles at 1C. Furthermore, economic and environmental analyses demonstrate this method’s superior cost-effectiveness and sustainability. Therefore, the method proposed in this study is efficient, simple and avoids the complex process of element separation, innovatively using a single reagent to achieve closed-loop recycling of LFP batteries, providing a novel and effective solution for the resource sustainability application.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 6","pages":"4226 - 4240"},"PeriodicalIF":9.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructural and textural evolution of high-purity Ti sheet with dense preexisting twins during isochronal and isothermal annealing","authors":"Yuan-Zhuo Liu,&nbsp;Lin-Jiang Chai,&nbsp;Tao Yang,&nbsp;Jing-Yi Zhang,&nbsp;Xing Hu,&nbsp;Zhong-Wei Wang,&nbsp;Fei Guo","doi":"10.1007/s12598-024-03181-y","DOIUrl":"10.1007/s12598-024-03181-y","url":null,"abstract":"<div><p>A high-purity Ti sheet with dense preexisting twins (introduced by 10% cold rolling) was subjected to isochronal annealing at 500–800 °C for 1 h and isothermal annealing at 600 °C for 0.17–100 h, respectively. By mainly utilizing electron backscatter diffraction (EBSD) and electron channel contrast (ECC) imaging techniques, the microstructure and texture evolution during the isochronal and isothermal annealing were investigated systematically. Results show that recrystallization nuclei appear in the specimen annealed at 600 °C for 1 h. In contrast, recrystallization cannot be initiated for those annealed at lower temperatures or for a shorter time. With the increase in temperature or time, the fraction of the recrystallized structure increases with gradual grain coarsening. Nearly complete recrystallization is reached after 800 °C-1 h or 600 °C-100 h annealing. Due to the distribution heterogeneity of microstructure and stored energy induced by the dense preexisting twins, recrystallization nucleation preferentially occurs in some specific regions (twin-twin or twin-grain boundary junctions). Then, they selectively consume twin lamellar structures, leading to non-uniform grain growth. It is demonstrated that the recrystallization nucleation is dominated by the strain-induced boundary migration mechanism, allowing scattered texture components corresponding to the twin lamellar structures to be gradually encroached by those un-twinned structures with the initial bimodal basal texture (BBT). Eventually, a strong BBT is always obtained after sufficient recrystallization.</p></div>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 6","pages":"4173 - 4190"},"PeriodicalIF":9.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hierarchical nitrogen-doped multichannel carbon nanofibers for efficient potassium–selenium batteries","authors":"Jae Bong Lim,&nbsp;Hyun Jin Kim,&nbsp;Jeong Ho Na,&nbsp;Jin Koo Kim,&nbsp;Seong-Yong Jeong,&nbsp;Seung-Keun Park","doi":"10.1007/s12598-024-03133-6","DOIUrl":"10.1007/s12598-024-03133-6","url":null,"abstract":"<div><p>K–Se batteries have been identified as promising energy storage systems owing to their high energy density and cost-effectiveness. However, challenges such as substantial volume changes and low Se utilization require further investigation. In this study, novel N-doped multichannel carbon nanofibers (h-NMCNFs) with hierarchical porous structures were successfully synthesized as efficient cathode hosts for K–Se batteries through the carbonization of two electrospun immiscible polymer nanofibers and subsequent chemical activation. Mesopores originated from the decomposition of the polymer embedded in the carbon nanofibers, and micropores were introduced via KOH activation. During the activation step, hierarchical porous carbon nanofibers with enhanced pore volumes were formed because of the micropores in the carbon nanofibers. Owing to the mesopores that enabled easy access to the electrolyte and the high utilization of chain-like Se within the micropores, the Se-loaded hierarchical porous carbon nanofibers (60 wt% Se) exhibited a high discharge capacity and excellent rate performance. The discharge capacity of the nanofibers at the 1,000th cycle was 210.8 mA·h·g⁻¹ at a current density of 0.5C. The capacity retention after the initial activation was 64%. In addition, a discharge capacity of 165 mA·h·g⁻¹ was obtained at an extremely high current density of 3.0C.</p></div>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 6","pages":"3839 - 3851"},"PeriodicalIF":9.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in rare metal catalysis for common CO2 reduction reactions","authors":"Shi-Jie Liu,&nbsp;Ting-Ting Hu,&nbsp;Hong-Qi Chu,&nbsp;Zhen-Zi Li,&nbsp;Wei Zhou","doi":"10.1007/s12598-024-03182-x","DOIUrl":"10.1007/s12598-024-03182-x","url":null,"abstract":"<div><p>Carbon dioxide (CO₂) emission significantly impacts global climate change, emerging as a critical developmental issue for humanity. Carbon cycling has been established as an effective strategy to address this challenge. Consequently, the conversion of atmospheric CO₂ into commercially valuable carbon via catalytic reaction pathways presents substantial potential. Rare metals exhibit unique properties, including high-temperature resistance, corrosion resistance, substantial hardness, and commendable electrical and thermal conductivity. Research advancements concerning rare metals have substantiated their potential environmental and economic advantages. Herein, we first summarize the fundamental concepts and applications of electrocatalysis, photocatalysis, photoelectrocatalysis, and photothermal catalysis in CO₂ reduction (CO₂R) reactions (CO₂RRs). The catalysts are classified at the atomic scale, and the influence of catalysts on CO₂RRs at this scale is discussed. Second, we thoroughly examine the relationship between rare metal materials and the selectivity of CO₂R products. Third, we provide a comprehensive overview of the latest advancements in the application of rare metals in CO₂R, as well as the reaction mechanisms of CO₂R catalysts, through the lens of advanced characterization technologies. Finally, we propose potential opportunities and future directions for the development of rare metals in CO₂R.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 6","pages":"3622 - 3652"},"PeriodicalIF":9.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achieving colloidal stability of diluted MXene dispersions through corrosion inhibition strategy with sodium tartrate","authors":"Hang Li,&nbsp;Bao-Min Fan,&nbsp;Hua Tian,&nbsp;Shi-Hao Wang","doi":"10.1007/s12598-024-03194-7","DOIUrl":"10.1007/s12598-024-03194-7","url":null,"abstract":"<div><p>The limited chemical and dispersive stabilities of transition metal carbides and nitrides (MXenes) significantly hinder their practical applications despite the demonstrated excellent performances. In this study, colloidally stable Ti₂CT_<i>x</i>- and Ti₃C₂T_<i>x</i>-MXene aqueous dispersions (0.1 mg·mL⁻¹) were achieved through a corrosion inhibition strategy by incorporating sodium tartrate (ST). The addition of ST (0.3 mg·mL⁻¹) effectively increased the activation energy and enthalpy for the degradation of Ti₂CT_<i>x</i> and Ti₃C₂T_<i>x</i> in aqueous solutions, largely extending their time constants to 565.5 h and 239.3 days, respectively. This strong oxidation inhibition effect of ST preserved the structural integrity and colloidal properties of both MXenes without compromising their electrical and electrochemical performances. The vacuum-filtered Ti₂CT_<i>x</i> and Ti₃C₂T_<i>x</i> film electrodes demonstrated capacitance retentions of 96.7% and 88.5% after 96 h and 24 days of aging at 25 °C, respectively. Multiscale simulations revealed that single-deprotonated ST⁻ preferentially adsorbed onto edges and defect sites of MXene nanosheets via oxygen heteroatoms on the carbonyl moiety bonding to Ti vacancies. This work offers a promising and straightforward approach to stabilize the diluted MXene aqueous dispersions, fundamentally address their oxidation issues, and meet the requirements for temporary storage.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 6","pages":"3893 - 3908"},"PeriodicalIF":9.6,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing hydrogen storage properties of Ti–Cr–(FeV80) alloys via pre-refining of FeV80 alloy with Y/Zr addition","authors":"Song-Song Li,&nbsp;Hua-Zhou Hu,&nbsp;Xiao-Xuan Zhang,&nbsp;Chen-Yu Li,&nbsp;Rui-Zhu Tang,&nbsp;Xin-Cong He,&nbsp;Ming Chen,&nbsp;Yong-Bing Zhong,&nbsp;Zhao Feng,&nbsp;Yan-Chao Ouyang,&nbsp;Jing-Wen Xu,&nbsp;Qing-Jun Chen","doi":"10.1007/s12598-024-03184-9","DOIUrl":"10.1007/s12598-024-03184-9","url":null,"abstract":"<div><p>Efficient, safe, and economical hydrogen storage technology is vital for hydrogen’s broad use as an energy carrier, with V-based BCC alloys standing out for their high theoretical storage capacity. However, the high cost of V has restricted their practical application. In this work, a cost-effective Ti–Cr–(FeV80) alloy was successfully synthesized through a pre-refinement process involving the addition of Y/Zr to the FeV80 alloy. The resulting Ti₂₇Cr₂₇(FeV80 + Y)₄₆ alloy exhibited an effective dehydriding capacity of 2.3 wt%, with a capacity retention rate of 97.2% after 200 cycles. Through the analysis of HSC Chemistry 6.0 software and backscattered electron (BSE), it has been discovered that the pre-refinement process significantly reduces the presence of Al, Si, and O impurities, leading to improved compositional uniformity. After the re-refinement, the formation of the Ti–rich phases had been notably curbed. This, along with a marked decrease in the pressure–composition–temperature (PCT) curve’s slope factor from 1.58 to 0.36, results in enhanced hydriding capacity (from 3.2 wt% to 3.7 wt%), reversible dehydriding capacity (from 2.0 wt% to 2.3 wt%), and a remarkable increase in the capacity retention rate (from 75.8% to 97.2%). The kinetics and thermodynamic properties of the alloys were calculated using the Arrhenius and Van’t Hoff equations, providing insights into their performance characteristics. The mechanism behind the alloy’s improved cyclic stability has been elucidated through an analysis of lattice distortion and X-ray photoelectron spectroscopy (XPS). These findings open new routes for the development of cost-effective FeV80-based hydrogen storage materials.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 6","pages":"4137 - 4148"},"PeriodicalIF":9.6,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The formation of adjoining twin pairs in TiAl alloys","authors":"Yan Liu,&nbsp;Jin-Shan Li,&nbsp;Bin Tang,&nbsp;Lu-Meng Wang,&nbsp;Kai-Di Li,&nbsp;Chun-Ming Liu","doi":"10.1007/s12598-024-03191-w","DOIUrl":"10.1007/s12598-024-03191-w","url":null,"abstract":"<p>Twinning is an important deformation mechanism in engineering materials, which can improve the ductility and strength of alloys, especially in the case of low-plasticity TiAl alloys. Herein, a large number of γ twins, twin intersections and adjoining twin pairs (ATPs) are formed in globular γ (γ-glob) phase after high-temperature tensile deformation. The ATPs consist of two sets of deformation twins (DTs) that are mirror symmetric about the original twin boundary (OTB). Its formation mechanism is analyzed with electron back-scattered diffraction (EBSD) and transmission electron microscope (TEM). The results reveal that the ATPs are related to the strain coordination between the DTs and the adjacent grains. Specifically, as the DT is formed in the γ-glob and impinges on the OTB, it will induce another γ twin (IT) in the adjacent γ-glob. The combination of the two γ twins generates ATPs, which are formed by the transmission of a twin from one grain to the neighboring grain. Moreover, γ twins with a lower Schmidt factor (SF) of 0.2643 are preferentially formed over another γ twin with a higher SF (0.3098) in the same γ-glob grain, because γ IT accommodates the strain caused by the γ DT in adjacent grain. Besides, the long-period stacking ordering (LPSO) structure of periodic contrasts 1 (PC₁) and PC₂ are observed in γ twins, which are considered to be the intermediate phase for the formation of γ twins. The current work elucidates the formation mechanism of ATPs in TiAl alloy and provides insights into the formation of twins in the γ-glob.</p>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 6","pages":"4162 - 4172"},"PeriodicalIF":9.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adsorption of rare earth elements and aluminum on the surface of kaolinite: insights from sequential chemical extractions, XAFS, and DFT","authors":"Jia-Xin Pan,&nbsp;Long-Sheng Zhao,&nbsp;Zheng Li,&nbsp;Zong-Yu Feng,&nbsp;De-Peng Liu,&nbsp;Jun Chen,&nbsp;Xiao-Wei Huang","doi":"10.1007/s12598-024-03141-6","DOIUrl":"10.1007/s12598-024-03141-6","url":null,"abstract":"<div><p>To achieve selective leaching of ion adsorption rare earth, it is necessary to thoroughly reveal the differences in the adsorption mechanisms of aluminum and rare earth elements. In this study, we investigated the adsorption processes of Dy and Al on the surface of K–homoionic kaolinite using batch experiments and sequential chemical extractions. The results revealed that the adsorption of Dy and Al, as well as the desorption of K, followed the Langmuir model. The maximum ion-exchangeable capacity of Dy was higher (9.39 mmol·kg⁻¹) than that of Al (6.30 mmol·kg⁻¹). The ion exchange stoichiometry ratios of Dy–K and Al–K derived from the Langmuir model were 2.0 and 2.6. The analysis of X-ray absorption fine structure (XAFS) and density functional theory (DFT) revealed that Dy and Al were adsorbed onto kaolinite as outer-sphere hydrated complexes via hydrogen bonds. Dy was adsorbed as [Dy(H₂O)₁₀]³⁺, and Al was adsorbed as [Al(OH)₂(H₂O)₄]⁺. In particular, the adsorption of Al resulted in protonation of the hydroxyl groups on the surface of the kaolinite. Based on the above insights, the higher ion exchange stoichiometry ratios are attributed to closer adsorption distances (6.04 Å for Dy and 3.69 Å for Al) and lower adsorption energies (− 223.72 kJ·mol⁻¹ for Dy and − 268.33 kJ·mol⁻¹ for Al). The maximum ion-exchangeable capacity is related to the change of the surface electrical properties of kaolinite. The zeta potential was increased to − 7.3 mV as the protonation resulted from aluminum adsorption, while Dy adsorption had a minor effect, maintaining a value of − 17.5 mV.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 6","pages":"4268 - 4278"},"PeriodicalIF":9.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}