Carbon Nanospheres Research Articles

Preparation of Multi-element Doped Carbon Nanospheres with Core-shell Structure Derived from Polystyrene as Lubricating Additives for Improving Tribological Behavior

In this study, the multi-element doped carbon nanospheres with core-shell structure (N,P,S-PCNs) have been successfully synthesized through the carbonization of hyper-cross-linked polystyrene nanospheres (HPSs) encapsulated with poly(cyclotriphosphazene-co-4,4’-sulfonyldiphenol) (PZS). The phosphonitrilic chloride trimer can in-situ assemble on HPSs surface, forming a poly(phosphonitrilic chloride trimer) film via sulfonyldiphenol as cross-linking agent to obtain HPSs@PZS. Subsequently, the HPSs@PZS undergoes high-temperature calcination under N2 atmosphere, and PZS with a well-preserved encapsulation capability efficiently incorporated N, P and S into carbon nanospheres to gain multi-element (N,P,S) co-doped carbon nanospheres (N,P,S-PCNs) with core-shell structure. The prepared N,P,S-PCNs exhibit exceptional dispersibility and stability as lubricant additives, effectively mitigating friction (reduced to 0.106) and wear (decreased by 84.0 %). The lubrication performance of N,P,S-PCNs is exceptional due to the nanospheres' remarkable ability to enter the gaps between friction pairs and form a deposition film on the surfaces. Moreover, the nanospheres can undergo a chemical reaction with the matrix surface, resulting in the formation of a chemical protective film. The composite protective film (deposition film and chemical protective film) significantly enhances the lubricants' ability to reduce friction and resist wear.

Fabrication of Vanadium Oxide-encapsulated Hybrid Carbon Nanospheres for Enhanced Tribological Performance.

A new sulfur-containing carbon nanospheres encapsulated with vanadium oxide (V@SCN) is synthesized through a one-pot oxidation polymerization and then carbonization method. The prepared V@SCNs exhibit good dispersibility as a lubricant additive, which is owing to the inherited lipophilic organic functional groups in the sulfur-containing carbon shell derived from the carbonization of polythiophene. The agglomeration and precipitation of metals in the base oil are also avoided through the encapsulation of lipophilic carbon shells. The stress and thermal simulation results show that the vanadium oxide core bestows upon the carbon nanospheres enhanced load resistance and superior thermal conductivity, which contributes to their excellent tribological properties. Introducing 0.04M-V@SCN to the base oil leads to favorable tribological characteristics, such as a fourfold rise in extreme pressure capacity from 250 to 1050N, a reduction in friction coefficient from 0.2 to ≈0.1, and a substantial decrease in wear by 90.2%. The lubrication mechanism of V@SCNs as lubricant additive involves the formation of a robust protective film on the friction pair, which is formed via complex physical and chemical reactions with the friction pair during friction.

One-pot synthesis of porous carbon nanospheres supported CuPd alloy catalysts for the hydrogenation-dechlorination of 2,3,6-trichloropyridine

Hydrogenation-dechlorination to produce 2,3-dichloropyridine is important for the next-generation pesticides. In this work, we successfully synthesized porous carbon nanospheres supported CuPd alloy nanoparticles via a simple and efficient one-pot strategy. Furthermore, by adjusting the Cu/Pd ratio and carbonization temperature, the obtained Cu2Pd1@PCNs-500-H2O2 showed the highly catalytic activity for the hydrogenation-dechlorination of 2,3,6-trichloropyridine with a conversion rate of 70.1 % and selectivity of 71.2 %. The catalyst showed outstanding catalysis performance even after five cycles. This simple and rapid one-pot strategy provides a new approach for the large-scale synthesis of efficient heterogeneous catalysts and offers an effective solution for reducing the high costs associated with precious metals.

A molecular-chemistry-manipulation strategy toward functional lignin-based porous carbon nanospheres with tunable-pore structure

Porous carbon nanospheres derived from biomass materials have inspired numerous interests in various areas. Nevertheless, their fabrications mainly depend on template-assisted or chemical activation routes. Here, a molecular-chemistry-manipulation strategy was proposed innovatively by taking advantage of the heterogeneous self-condensation characters of lignin molecules under thermal stimulation, opening a practical and versatile synthetic platform for the construction of lignin-based hierarchical porous carbon nanospheres (LHPCS). We can manipulate the condensed kinetics by tuning the environmental variables and forming designated nanospheres with inhomogeneous molecular chemistry. This intraparticle difference could provide a possibility to tune its refined structure for synthesizing hierarchical porous carbon nanospheres. Such LHPCS behaved the specific surface area of 962 m2 g−1 and pore volume of 0.76 cm3 g−1, as well as regulable pore ratios (15.5–22.9 % of macropore, 12.7–37 % for mesopore and 45–68.9 % for micropore). Besides, the monodisperse spherical morphology with hierarchical interleaved channels affords them excellent performance in optical management and energy storage, including pore-determined photothermal properties, extremely low reflectance of ca. 1.9 %, stable multi-angles specular reflectance, and anti-self-discharge induced by charge rearrangement. Our proposed molecular chemistry strategy provides an alternative pathway for constructing gradient and adjustable pore structures.

Co nanoparticles confined in N-doped hollow carbon nanospheres as multifunctional oxidase mimic for colorimetric detection of L-Cysteine and Hg2+

In contrast to peroxidase-mimicking nanozymes, oxidase mimics directly employ molecular oxygen (O2) as oxidant to generate reactive oxygen species (ROS). Generally, transition metal-based nanozymes exhibit poor oxidase-like activity. We herein constructed a colorimetric sensor based on Co-based oxidase mimic, where the Co nanoparticles were encapsulated in hollow N-doped carbon nanospheres (Co-N/C). Co nanoparticles confined catalyst effectively anchored the active part, which greatly influenced the catalytic activity of the oxidase-mimic nanozymes. Due to the antioxidative property of L-Cysteine (L-Cys) and the specific complexation between L-Cys and Hg2+, the rationally designed Co-N/C could be utilized to detect L-Cys and Hg2+. The proposed sensing platform exhibited wide linear ranges of 1–30 μM for L-Cys and 0.6–30 μM for Hg2+, respectively. The excellent selectivity of the constructed sensor showed the reliability and practicality for the assay of L-Cys and Hg2+ in fetal bovine serum. The spatial confinement can prevent the aggregation of Co nanoparticles, boosting the stability and catalytic performance in colorimetric sensing.

Simple and efficient enrichment and separation of glycoprotein by teamed boronate affinity magnetic carbon nanospheres

Protein glycosylation is a key regulatory mechanism that controls many physiological and pathological processes. Analyses of glycoproteins in biological samples require challenging enrichment steps in light of sample complexity and low glycoprotein abundance. Here, in order to develop an efficient method to enrich glycoproteins, a magnetic carbon nanospheres (MCs) rich in amino group and polyboric acid sites was designed and prepared. The teamed boronate affinity was formed by the self-assembled of amino group and boric acid, which can specifically capture glycoprotein containing cis-diol under neutral conditions. Firstly, a simple green hydrothermal method led to the production of a carbon nanospheres matrix with abundant surface hydroxyl and carboxyl moieties. Then, MCs were synthesized by solvothermal method. Subsequently, the MCs were modified with polyethyleneimine and boric acid in turn to obtain the proposed composite. The hydrophilicity of amino group and its hydrogen bond with glycoprotein, as well as the cyclization reaction of boric acid with cis-1,2-diol, are utilized to specifically bind to glycoprotein. The prepared magnetic nanospheres exhibited binding to glycoproteins with rapid kinetics and strong affinity. Adsorption equilibrium was reached within 40 min, and the adsorption capacities for the glycoproteins ovalbumin, transferrin and horseradish peroxidase were found to be 493, 346 and 326 mg/g, respectively, while the adsorption capacities for the non-glycoproteins bovine serum protein and lysozyme were 60 and 30 mg/g, respectively. This novel nanoparticle provides a simple and efficient method for the enrichment and separation of glycoproteins from biological samples.

Strong metal-support interaction induced by oxygen vacancies to enhance the activity and durability of Pt/TiO2/ hollow carbon nanospheres ORR catalyst

For the commercial Pt-loaded carbon ORR catalysts used in proton exchange membrane fuel cells (PEMFC), carbon support corrosion, along with the migration and aggregation of Pt nanoparticles (NPs) due to the weak interaction between Pt NPs and carbon, leads to a drastic reduction in both electrocatalytic activity and stability. Hence, exploring active and steady supports is crucial to restrain the activity loss and stabilize Pt catalysts. In this work, a composite support consisting of hollow carbon nanospheres (HC) and TiO2 NPs with abundant oxygen vacancies (OV) loaded with Pt NPs (PTHC-H) was designed and synthesized. Experiment results show that PTHC-H exhibits superior activity and stability compared to PTHC-N (TiO2 with lower OV content) and commercial Pt/C catalyst. Specifically, PTHC-H delivers a half-wave potential of 0.883V versus reversible hydrogen electrode. And its mass activity and half-wave potential decrease by only 15.96% and 7mV, respectively, after 10,000 cycles of accelerated durability testing. The excellent activity and stability are ascribed to the enhanced metal-support interaction induced by OV, which can optimize the Pt d-band center and suppresses the migration and aggregation of Pt NPs. This work may be favorable for designing efficient and durable anti-corrosion nano catalysts.

Tribological properties of oil impregnated carbon nanocapsules modified with polydopamine-polyethyleneimine

Self-lubricating microcapsules can reduce the coefficient of friction/wear and improve the tribological properties of polymer composites. Impregnation of prefabricated shell with core substances is a versatile and applicable route to obtain the microcapsules. In this work, double shell nanocapsules (PA@C HSM) with particle size of 448nm, shell thickness of 65nm are obtained by incorporating paraffin wax (PA) into the pre-synthesized hollow carbon nanospheres (PHCs)and then packaged by co-depositing with polydopamine (PDA) and polyethylenimine (PEI). The PDA/PEI transition shell increase the surface roughness of the nanocapsule and enhance the compatibility with the polymer matrix which will contribute to the improved oil storage ability and thermal stability of the nanocapsules as well. The distinguished mechanical interlocking and chemical interface bonding between PDA/PEI layer and EP matrix effectively facilitates mitigating the unfavorable impact of PA@C HSM on the mechanical properties of the composite with the modulus of the 7.5wt.% PA@C HSM/EP composites increased by 17.44%. As for the tribological performance of PA@C HSM/EP composite, the tribological properties are boosted remarkably and the friction coefficient and wear rate of 7.5%PA@C HSM/EP composite are reduced by 77.69% and 98.79% compared with pure EP material.

Mesoporous carbon nanospheres doped with rich non-metallic and metallic catalytic active sites: A high-performance electrochemical platform for sensing of chloramphenicol in food samples

The development of a low-cost, accurate sensing strategy for trace levels of chloramphenicol (CAP) residues in food is crucial but remains challenging. In this study, a high-performance electrochemical platform was developed to detect CAP in animal-derived foods using Ni2P embedded N, P-co-doped mesoporous carbon nanospheres (Ni2P@N,P-MCS). The Ni2P@N,P-MCS material, with a unique mesoporous structure and large specific surface area, exhibited excellent adsorption properties. The N, P-co-doped heteroatoms enhanced the electric conductivity and active centers of MCS, facilitating fast mass transport and electron transfer. The introduction of Ni2P increased the active sites and enhanced the electrocatalytic activity. Leveraging these advantages, the electrochemical sensor based on Ni2P@N,P-MCS demonstrated outstanding detection performance with a wide linear range from 0.04 to 250 μM and a low limit of detection of 12 nM. The sensor also showed good reproducibility, stability, and anti-interference properties. Furthermore, the sensor was successfully tested in milk and pork samples, showing satisfactory recovery rates and indicating its feasibility for real sample analysis.

Microstructure evolution and high-temperature oxidation behavior of low-carbon MgO-C refractories with TiB2 addition

Combining the advantages of both containing-B compounds and containing-Ti compounds, a new TiB2 addition is proposed in MgO-C refractories. In this paper, the high-temperature oxidation behavior of low-carbon MgO-C refractories with TiB2 addition was investigated, especially the effect of microstructure and phase evolution on the high-temperature oxidation behavior was discussed. The results show that in the materials, TiB2 preferentially reacts with oxygen, forming TiCxN1-x, Mg3(BO3)2 and Mg2TiO4 ceramic phases, and catalyzing the decomposition of phenolic resin to form bamboo-like nanotubes and carbon nanospheres to bond aggregates and fill pores. Meanwhile, TiB2 also promotes the formation of regenerated MgO compact zone, hindering the diffusion of oxygen into the materials to improve the oxidation resistance. Compared with the blank control specimen and the specimen with B4C addition, the oxidation resistance increased by 243.4 % and 79.2 %, respectively.

Three-dimensional porous structure CoP/N-doped carbon nanospheres as anode for enhanced lithium storage performance

Transition metal phosphides (TMPs) with high theoretical capacities and safe operating voltage are recognized as prospective anode materials for lithium-ion batteries (LIBs). While, the huge volume expansion and low conductivity of TMPs still restrict their applications. Engineering nanostructured composites consisting of TMPs and conductive carbon-based materials is of great importance to improve electrochemical performance. Herein, a novel and facile pyrolysis-oxidation-phosphidation approach is designed to fabricate porous nanospheres composing of CoP nanoparticles and N-doped carbon substrate. The abundant pores in CoP/N-C provide ample active sites for lithium storage and facilitate Li+ transport. The introduction of N-doped carbon substrate enhances the electrical conductivity, allowing CoP to maintain its structure during cycling. The CoP/N-C anode achieves remarkable cycle performance, maintaining an extremely stable cycle life over 2000 cycles at 5 A g−1. More importantly, the full cell consisting of CoP/N-C and LiFePO4 also exhibits a prominent cycling durability with a capacity retention of 96.5 % at 0.1 A g−1 after 150 cycles. This work proposes a simple and feasible structural engineering strategy, which can provide a new way for optimizing the electrochemical performance of conversion-type anode materials.

N-doped carbon nanospheres synthesized from a newly designed eco-friendly sustainable polymer for highly selective CO2 capture.

N-doped carbon nanospheres and porous carbon were produced by a hydrothermal template and the activation of hexamethylenetetramine (HMTA as a nitrogen source and activator) and ZnCl2 (only as an activator) from a poly(Ri-S-ε-CL-PDMS) multiblock/graft copolymer produced using a renewable resource and eco-friendly autoxidation. N-doped carbon nanospheres (PPiSiHMTA) exhibited excellent CO2 adsorption (2.73mmol/g at 0°C and 0.15atm, 1.72mmol/g at 25°C and 0.15atm) and CO2/N2 selectivity (344-512). Despite the higher BET surface area and pore volume, porous carbon (PPiSi) showed low CO2 adsorption (1.21 and 0.71mmol/g, 0.15atm) and CO2/N2 selectivity (57 and 112). PPiSiHMTA and PPiSi have low isosteric heats of adsorption (Qst, 18-33kJ/mol) and stability in humid environments. In addition, PPiSiHMTA exhibited an excellent CO2 recycling performance. The experimental data on CO₂ adsorption was evaluated using various isotherm models, including Freundlich, Langmuir, Sips, and Temkin. The results demonstrated a nearly perfect fit between the Freundlich isotherm and the experimental data, indicating the heterogeneous nature of the adsorbent surfaces. Our study is promising for industrial applications, offering excellent CO2 adsorption, CO2/N2 selectivity, moisture stability, and porous material fabrication strategies.

P300/CBP KATs Are Critical for Maturation and Differentiation of Adult Neural Progenitors.

Epigenetic modifications play a pivotal role in the process of neurogenesis. Among these modifications, reversible acetylation fine-tunes gene expression for both embryonic and adult neurogenesis. The CBP/KAT3A and its paralogue p300/KAT3B are well-known lysine acetyltransferases with transcriptional coactivation ability that engage in neural plasticity and memory. The exclusive role of their KAT activity in neurogenesis and memory could not be addressed due to the absence of a p300/CBP modulator, which can cross the blood-brain barrier. Previous work from our laboratory has shown that a small molecule activator, TTK21, specific to CBP/p300, when conjugated to glucose-derived carbon nanospheres (CSP), is efficiently delivered to the mouse brain and could induce dendritic branching and extend long-term memory. However, the molecular mechanisms of p300 acetyltransferase activity-dependent enhanced dendritogenesis are yet to be understood. Here, we report that CSP-TTK21 treatment to primary neuronal culture derived from mouse embryo enhances the expression of five critical genes: Neurod1 (central nervous system development), Tubb3 (immature neural marker), Camk2a (synaptic plasticity and LTP), Snap25 (spine morphogenesis plasticity), and Scn2a (propagation of the action potential). Activation of these genes by inducing the p300/CBP KAT activity presumably promotes the maturation and differentiation of adult neuronal progenitors and thereby the formation of long and highly branched doublecortin-positive functional neurons in the subgranular zone of the dentate gyrus.

Photothermal effectiveness of microporous carbon nanospheres incorporated with polysulfone in direct contact membrane distillation.

Carbon nano-spheres (CNS) were synthesized via a hydrothermal method using d-glucose as a precursor, followed by pyrolysis in a nitrogen atmosphere. The resulting CNS were integrated into polysulfone (PSF) membranes to enhance their photothermal properties. Characterization using various techniques revealed improved thermal properties upon CNS inclusion, with a notable increase in membrane surface temperature and enhancement of contact angle (CA) and liquid entry pressure (LEP). Composite PSF membranes containing varying CNS concentrations (0.25-5%) exhibited optimal performance at 3% CNS concentration, demonstrating enhanced morphological conformation and photothermal attributes. Evaluation under tungsten bulbs light using a photothermal membrane distillation system showed significant improvement in membrane distillation flux, achieving a maximum water flux of 7.73 L m-2 h-1 and a salt rejection rate of 99.9%. These findings highlight the potential of hydrothermal CNS in enhancing photothermal properties and membrane performance for applications in desalination and wastewater treatment.

Engineered nanozyme-cascade catalyzed reaction for rapid acid phosphatase detection

The utilization of artificial multienzyme-catalyzed cascade reactions have greatly benefited biosensors. This study presents a novel nanoreactor consisting of manganese ions-doped hollow carbon nanospheres (Mn@HCNs), which can rapidly transform molecular information into an easily comprehensible colorimetric signal. The Mn@HCNs nanoreactor was utilized to detect acid phosphatase (ACP) within a range of 0.5–10 mU/mL, achieving a limit of detection (LOD) as low as 0.0851 mU/mL. The superiority of our nanoreactor over traditional ACP detection methods stems from its exceptional substrate affinity and the multi-enzymatic behaviors of Mn@HCNs. Especially, the specific POD-like activity (SA) value of Mn@HCNs was superior to most reported Fe3O4 and other single-atom enzymes. Furthermore, this nanoreactor exhibited exceptional selectivity against protein and ion interference, and was furthered to detect ACP in clinical serum samples. The work may extend the development of artificial multienzyme-catalyzed cascade reactions for molecular biosensors and clinical application.

Lipid-Conjugated Reduced Haloperidol in Association with Glucose-Based Nanospheres: A Strategy for Glioma Treatment.

Aggressive glioma exhibits a poor survival rate. Increased tumor aggression is linked to both tumor cells and tumor-associated macrophages (TAMs), which induce pro-aggression, invasion, and metastasis. Imperatively, for effective treatment, it is important to target both glioma cells and TAMs. Haloperidol, a neuropsychotic drug, avidly targets the sigma receptor (SR), which is expressed in higher levels in both the cell types. Herein, we present the development of a novel cationic lipid-conjugated reduced haloperidol (±RHPC8), which aims to mediate the SR-targeted antiglioma effect. Hypothetically, ±RHPC8 would act simultaneously as an SR-targeting ligand and anticancer agent. As the blood-brain barrier (BBB) obstructs direct targeting of in situ glioma, we used BBB-crossing glucose-based carbon nanospheres (CSPs) to deliver ±RHPC8 within the glioma tumor-bearing mouse brain. The resultant ±RHPC8-CSP nanoconjugate targeted SR-expressing glioma cells. In both orthotopic and subcutaneous mouse tumor models, ±RHPC8-CSP prolonged survival and regressed tumors compared to other treated groups. Notably, ±RHPC8-CSP was significantly taken up by SR-expressing TAMs thus resulting in macrophage polarization from M2 to M1, as exhibited by markedly reduced expression of immunosuppressive cytokines released by TAMs, including TGF-β, IL-10, and VEGF. In conclusion, the designed ±RHPC8-CSP nanoconjugate presented an effective nanodrug delivery system for brain cancer treatment.

Upcycling sugar beet waste into sustainable organo-nanocatalysis for carbon dioxide fixation and cyclic carbonate synthesis: a research design study

Environmental pollution is a major global issue due to the increase of various pollutants all over the world. Enhancing pollutant remediation strategies for environmental sustainability necessitates increasing the efficiency of conventional methods or introducing innovative approaches. Nanotechnology, particularly carbon-based nanomaterials, offers substantial promise due to their high surface area and absorption potential. Concurrently, organocatalysts have emerged as sustainable and versatile alternatives to traditional metal-based catalysts in modern chemical research. This study highlights the synthesis and application of organo-nanocatalysts derived from biomass, specifically a spherical carbon nanocatalyst synthesized from sugar beet pulp. This novel green catalyst, characterized by high selectivity and efficiency, successfully converts epoxides and CO2 into valuable cyclic carbonates under solvent-free conditions. The hydroxyl groups on the Sugar Beet-derived Carbon NanoSphere (SCNS) surface act as Bronsted acid sites, facilitating epoxide activation via hydrogen bonding. The integration of carbon-based nanomaterials and organocatalysis represents a promising, sustainable solution for pollutant remediation and green chemistry advancements.Graphical

An Unusual Application of Multifunctional Nanozyme Derived from COF: Augmenting Chemoimmunotherapy while Attenuating Cardiotoxicity

AbstractEnhancing therapeutic efficacy while reducing the adverse effects of drugs is crucial in cancer treatments. In this study, nitrogen‐doped carbon nanospheres are synthesized with variable enzymatic activities through the pyrolysis of a covalent organic framework (COF). These nanospheres show increased peroxidase (POD) and oxidase (OXD) activities in the tumor microenvironment, generating reactive oxygen species (ROS) that help eliminate tumor cells. Under normal conditions, they display catalase (CAT) and superoxide dismutase (SOD) activities, promoting antioxidative protection. Their porous structure and π–π/hydrophobic interactions allow for the loading of the chemotherapeutic agent doxorubicin (DOX). The nanospheres are then enveloped by tumor cell membranes, stabilizing the drug load and enabling targeted drug delivery with pH‐sensitive release. This targeted system induces ferroptosis in tumor cells and activates a strong anti‐tumor immune response, leading to enhanced immunotherapy for breast cancer and reduced tumor metastasis to the lungs. Importantly, the varied enzymatic activities of the nanomedicine system help mitigate the cardiotoxicity of DOX chemotherapy, improving cancer treatment while minimizing side effects. This approach introduces a nano‐enzyme drug system with distinctive activities and innovative preparation, setting a new standard for efficient, low‐toxicity cancer therapy.

Boosting Li–S Battery Performance by Regulating Microstructures of Porous Hollow Carbon Nanospheres from Lignites

Boosting Li–S Battery Performance by Regulating Microstructures of Porous Hollow Carbon Nanospheres from Lignites

Selective electro-capacitive deionization of Yb(III) by nanospherical N-doped carbon supported nickel‑iron bimetallic oxide, nitride and phosphide

The separation of rare earth elements from the mining waste water is highly important but still facing challenge. In this study, three different porous composite electrode materials were well-designed by decorating the nickel‑iron bimetallic oxide, nitride or phosphide onto nitrogen-doped carbon nanosphere, respectively (termed as NiFeO@NC, NiFeN@NC and NiFeP@NC), and utilized in capacitive deionization device for electrosorption of Yb(III) from water under the low-voltage electric field. The characterization and electrochemical results indicated that the incorporation of N or P atom lead to the reduced specific surface area and the enhanced electrochemical properties (i.e., larger specific capacitance, lower charge transfer resistance). In addition, NiFeN@NC and NiFeP@NC exhibited the excellent electrosorption capacities of Yb(III) with 105.24 mg·g−1 and 90.31 mg·g−1, respectively, under conditions of a flow rate of 20 mL·min−1, a voltage of 1.2 V, and pH of 5.0, which was extremely higher than NiFeO@NC (i.e., 50.7 mg·g−1). Moreover, all these three materials also demonstrated the remarkable electrosorption selectivity of Yb(III) from the mixed solution, and the robust durability with over 90 % of initial capacities after ten consecutive electrosorption-desorption cycles. Furthermore, the XPS characterizations and electrosorption results revealed that the electrosorption mechanism mainly depended on the synergistic effects of intrinsic Faraday redox reaction, electric double layer capacitance and active binding sites. Therefore, this work provided a feasible strategy for the separation of rare earth elements from aqueous solution, and the prospective applications related to the recovery of rare earth elements from mining wastes or spent permanent magnets in future life.