Rare earth elements (REEs) are critical for modern technologies such as electric vehicles, wind turbines, and rechargeable batteries due to their unique properties. However, traditional mining methods for REE extraction are challenging, costly, and environmentally unsustainable due to their low concentration in ores and significant ecological impacts. Recycling REEs from end-of-life products, particularly nickel-metal hydride (NiMH) batteries, has emerged as a sustainable alternative to ensure a reliable supply of these vital elements. This paper reviews methods for recycling REEs from spent NiMH batteries, focusing on both traditional and eco-friendly leaching techniques, as well as selective separation and purification processes. Hydrometallurgical methods, including leaching with organic acids and deep eutectic solvents (DESs), offer advantages over pyrometallurgical or solvent extraction approaches due to lower energy consumption and reduced environmental impact. Compared with mining, the recovery of REEs from NiMH batteries not only mitigates CO2 emissions and reduces water/soil contamination but also, via biohydrometallurgy or DES, curbs energy consumption and the use of hazardous chemicals. Consequently, it prevents ecological disruption and protects biota. Also, from an economic perspective, it has become a sustainable and profitable option by saving on initial extraction costs and reducing energy and chemical consumption. The use of the hydrometallurgical method, due to its simplicity and high efficiency, can contribute to the circular economy, and for this purpose, the development of green technologies with low environmental impacts and high efficiency is vital in the future.
Triple-negative breast cancer (TNBC) has a high risk of postoperative recurrence in clinical practice for its high invasiveness and aggressiveness. Among postoperative treatment methods, redox therapy has attracted increasing attention for postoperative tumor treatment in recent years. Among various reactive oxygen species (ROS)-generating agents, persulfates, which generate the more therapeutically effective ·SO4−, show outstanding potential but are limited by their excessively rapid decomposition. To address this limitation, we developed a biodegradable, metabolizable, TME-unconstrained mild photothermal-controllable redox therapy in situ injectable postoperative implant, which was loaded with sodium persulfate nanoparticles (DSPE-PEG modified Na2S2O8 nanoparticles, PSNPs) and photothermal materials (DSPE-PEG modified NaNdF4, PNdNPs). Mild photothermal effect regulates the thermosensitive hydrogel and the decomposition rate of PSNPs to make the decomposition of PSNPs controllable. The PSNPs gradually release and decompose, generating ·OH and ·SO4− without being constrained by TME. With the decomposition of PSNPs, a substantial amount of Na+ is transported into cells through endocytosis, thereby bypassing conventional cellular ion transport mechanisms and enhancing the killing effect on tumors. Furthermore, the small-sized materials can be metabolized and expelled, exhibiting excellent biodegradability. This study introduces a novel mild photothermal-controllable redox therapy strategy for the postoperative management of triple-negative breast cancer.
The significant deactivation of CuO-CeO2 catalysts poisoned by Pb-containing species severely limits their practical application in low-temperature CO oxidation. Herein, the role of ZrO2 as a structural stabilizer in enhancing PbCl2 resistance of CuO-CeO2 catalysts was systematically investigated, with emphasis on lattice regulation and reaction mechanism preservation. The CuO-CeO2 catalyst supported on ZrO2 was prepared by impregnation and comprehensively characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR), CO temperature-programmed desorption (CO-TPD), and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) technologies. The ZrO2-supported CuO-CeO2 catalyst (CC/Zr) exhibits significantly enhanced tolerance to PbCl2 poisoning, as demonstrated by substantially smaller increases in T50 and T90 (temperatures with CO conversion of 50% and 90%, respectively) compared with the unsupported catalyst. ZrO2 incorporation promotes the formation of a CeO2-ZrO2 solid solution, which enhances lattice stability and suppresses Pb-induced structural degradation. Meanwhile, ZrO2 support effectively preserves surface Cu+ species, maintains higher Ce3+ concentration, and mitigates the loss of oxygen vacancies under poisoning conditions. As a result, both conventional and carbonate-mediated Mars-van Krevelen reaction pathways remain partially operative after PbCl2 exposure, enabling sustained low-temperature CO oxidation activity. This work elucidates the mechanistic insights into support-mediated poisoning resistance and provides a rational strategy for designing durable catalysts for CO oxidation in Pb-containing environments.
Global excessive use of fossil fuels has depleted energy resources and contributed to a rapidly deteriorating environment. This point has led researchers worldwide to devote significant effort to developing sustainable technologies for hydrogen generation and environmental remediation, as well as to developing a supercapacitor. Herein, we first report the synthesis of LaNiO3/CoMoO4 nanocomposites by a hydrothermal method. X-ray diffraction (XRD) result confirms the presence of crystalline phases, while scanning electron microscopy (SEM) and transmission electron microscopy (TEM) reveal a uniform morphology and nanoscale structure. X-ray photoelectron spectroscopy (XPS) result confirms the elemental composition, and UV-Vis spectroscopy analysis shows strong absorption in the visible region. Electrochemical studies in 3.0 mol/L KOH show excellent capacitive performance, as evidenced by cyclic voltammetry (CV), linear sweep voltammetry (LSV), Tafel slope, electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD), with a specific capacitance of 1 F/g. Also, GCD stability is achieved after 5000 cycles. As a bifunctional electrocatalyst, the composite exhibits low overpotentials of 190 mV for oxygen evolution reaction (OER) and 96 mV for hydrogen evolution reaction (HER) at 10 mA/cm2, and favourable Tafel slopes of 129 and 176 mV/dec, indicating high water-splitting efficiency. Furthermore, the LNO/CMO composite exhibits 91.39% degradation of the MR aqueous dye under sunlight within 30 min of illumination. These findings emphasise the versatile functionality of LNO/CMO nanocomposites, positioning them as strong candidates for advancing next-generation sustainable energy storage, clean energy conversion, and environmental remediation.
In the context of carbon neutrality and energy-system restructuring, developing efficient and sustainable energy and matter conversion technologies has become a key scientific issue. Electrocatalysis and photocatalysis, as core technological routes, show important application potential in hydrogen-energy production, carbon cycling, organic transformation, and related fields. This review systematically summarizes the research progress of rare-earth-based catalytic materials in representative systems, including the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), carbon dioxide reduction reaction (CO2RR), nitrate reduction reaction (NO3RR), organic small-molecule conversion, and biomass degradation. Particular emphasis is placed on their mechanistic roles in regulating interfacial electronic structures and constructing reaction microenvironments. By analyzing the effects of rare-earth 4f orbital characteristics and coordination structures on intermediate adsorption, charge transfer, and reaction pathways, this review summarizes the general rules by which rare earth elements enhance catalytic performance and stability, and further discusses their structural stability and performance evolution under practical reaction conditions. Finally, in view of current issues such as insufficient mechanistic understanding and unclear structure-activity relationships, future development directions and design strategies for rare-earth catalytic systems are proposed.
Precise management of energy transfer pathways in lanthanide-doped upconversion nanoparticles is crucial for advanced optical applications, yet it requires delicate spatial segregation of multiple lanthanide activators and sensitizers within a well-designed nanostructure. To address this challenge, a designed core-shell-shell-shell nanostructure with the composition NaErF4:Tm@NaYF4@NaGdF4:Yb,Tm@NaGdF4:Tb was successfully fabricated via a controlled layer-by-layer epitaxial growth strategy. By precisely controlling the thickness of the intermediate NaYF4 spacer layer, the interfacial energy transfer between the Er3+-doped core and the Yb3+/Tm3+-doped shell was effectively regulated, enabling a balanced combination of red, green, and blue emission components and achieving efficient white light emission under 980 nm excitation. Furthermore, the emission color can be dynamically tuned from red to white by varying the excitation power density. Based on this multicolor emission characteristic, a new anti-counterfeiting platform was developed, which selectively reveals valid encrypted information only under the correct combination of excitation wavelength and power, demonstrating high security and multi-level optical encryption capability.
Optical thermometry is an important non-contact temperature measurement technology. Among them, the single-band ratiometric (SBR) method has attracted increasing attention due to its high signal resolvability and ability to avoid spectral reabsorption. However, the improvement of the sensitivity of SBR thermometry is highly dependent on specific materials currently, lacking a universal regulatory mechanism. Herein, we employed Eu3+-doped La3TaO7 as the initial SBR thermometer, which operates based on the thermal enhancement at the edge of the O2− to Eu3+ charge transfer band (CTB). With the purpose of modulating the thermally induced shift of the CTB, two substitution strategies were proposed. One is Y3+/La3+ (RE3+) substitution, which will induce a phase transformation, and the other is Nb5+/Ta5+ (M5+) substitution, which could regulate the crystallographic lattice site. These modifications lead to respective 3-fold and 6-fold improvements in the relative sensitivity over the base LTO:0.6Eu3+ phosphor. Benefiting from the careful analysis of the chemical bond nature before and after substitution, the thermally induced redshift of the CTB can be attributed to the relaxation of structural stability. The Y3+/La3+ and Nb5+/Ta5+ substitution reduce the ionicity of the RE−O bonds and the covalency of the M−O bonds, leading to the lower structural stabilities and realizing the stronger sensitivities to temperature. As a result, the thermal enhancement at the CTB edge is significantly strengthened, and the relative sensitivities increase by several times. These results demonstrate a viable strategy for modulating the relative sensitivity of SBR-type thermometers, providing crucial support for the targeted design of high-performance SBR thermometers.
