Search Results (23)

In this study, red mud (RM) was utilized as an iron and aluminum source, and reed biomass served as a carbon precursor to prepare red mud-modified biochar beads (RM/CSBC) via the gel-calcination method. Under a pyrolysis temperature of 900 °C and an RM/biomass dosage of 3 g each, RM/CSBC exhibited an optimal balance between adsorption performance and cost. Within typical pH range of 6–9 in wastewater, RM/CSBC maintained effective adsorption performance, while metal ion leaching (Fe ≤ 0.3 mg·L⁻¹, Al ≤ 0.2 mg·L⁻¹) complied with Class II surface water standards in China. Kinetic data were well fitted by the pseudo second-order model, supported by the Elovich model, indicating the involvement of both chemical and physical adsorption mechanisms. Isotherm results showed that the Langmuir model provided the best fit, indicating monolayer adsorption, with a maximum capacity of 85.16 mg·g⁻¹ at 25 °C. XPS analysis revealed the formation of AlPO₄ and FePO₄ precipitates, confirming chemical precipitation as a key mechanism, along with electrostatic attraction and physical sorption. This study highlights the feasibility of RM/CSBC as an efficient and low-cost phosphate adsorbent and provides a theoretical basis for phosphorus removal and recovery from wastewater using waste-derived materials. Full article

Iron phosphate (FePO₄·2H₂O) was synthesized via anodic oxidation using nickel–iron alloy composition simulates from laterite nickel ore as the anode and graphite electrodes as the cathode, with phosphoric acid serving as the electrolyte. A uniform experimental design was employed to systematically optimize the synthesis parameters including voltage, electrolyte concentration, electrolysis time, and degree of acidity or alkalinity (pH). The results indicate that the addition of cetyltrimethylammonium bromide (CTAB) surfactant effectively modulated the morphology of the anodic oxidation products. The optimized conditions were determined to be an electrolyte concentration of 1.2 mol/L, a voltage of 16 V, a pH of 1.6, an electrolysis time of 8 h, and a 3% CTAB addition. Under these conditions, the synthesized FePO₄·2H₂O exhibited enhanced performance as a lithium-ion battery precursor. Specifically, the corresponding LiFePO₄/C cathode delivered an initial discharge capacity of 157 mA h g⁻¹ at 0.2 C, retaining 99.36% capacity after 100 cycles. These findings provide valuable insights and theoretical foundations for the efficient preparation of iron phosphate precursors, highlighting the significant impact of optimized synthesis conditions on the electrochemical performance of lithium iron phosphate. Full article

This study investigates advanced strategies for r regenerating and recycling lithium iron phosphate (LiFePO₄, LFP) materials from spent lithium-ion batteries. Recovery techniques are categorized into direct regeneration, which restores positive electrode materials with high electrochemical performance, and recycling, which produces intermediate compounds such as lithium carbonate and iron phosphate. Additionally, resynthesis methods are explored to convert recovered precursors into high-quality LFP materials, ensuring their reuse in battery production. Innovative approaches, including carbothermic reduction, doping, and hydrothermal resynthesis, are highlighted for their ability to enhance material properties, improve energy efficiency, and maintain the olivine structure of LFP. Key advancements include the use of eco-friendly reagents, automation, and optimization strategies to reduce environmental impacts and costs. Regenerated and resynthesized positive electrodes demonstrated performance metrics comparable to or exceeding commercial LFP, showcasing their potential for widespread application. This work underscores the importance of closed-loop recycling systems and identifies pathways for scaling, improving economic feasibility, and minimizing the ecological footprint of the lithium-ion battery lifecycle. Full article

Lithium iron phosphate (LiFePO₄) is a promising cathode material for lithium-ion batteries (LIBs), but its low conductivity and poor rate performance limit its application in high-power devices. In this study, we employed a particle size grading strategy to enhance the electrochemical performance of LiFePO₄. By mixing small and large particles in different ratios (3:1, 2:1, 1:1, 1:2, and 1:3), we synthesized graded iron phosphate precursors, which were then used to prepare LiFePO₄ cathode materials. The effects of particle size distribution on the material’s structural properties and electrochemical performance were systematically investigated. SEM images revealed that the morphology of LiFePO₄ changed with varying precursor ratios, with the 3:1 ratio resulting in a more uniform particle distribution. The results showed that the 3:1 ratio exhibited the highest discharge capacity of 159.4 mAh/g, while larger particle ratios (2:1 and 1:1) led to decreased capacity due to the increased proportion of larger particles. Additionally, the LiFePO₄ materials prepared from non-in situ mixed precursors exhibited higher tap densities, with the 2:1 ratio achieving the highest tap density of 2.545 g/cm³. This study demonstrates the effectiveness of the particle size grading approach in improving the electrochemical properties of LiFePO₄ and provides insights into the design of high-performance cathode materials for advanced lithium-ion batteries. Full article

This study investigates the effects of different titanium doping concentrations on the properties of iron phosphate precursors and the final lithium iron phosphate (LiFePO₄) materials, aiming to optimize the structural and electrochemical performance of LiFePO₄ by introducing titanium during the precursor synthesis stage. Titanium was introduced using titanate as a titanium source to prepare iron phosphate precursors with varying titanium concentrations. The materials were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and other techniques. The results showed that titanium incorporation significantly influenced the Fe and P content in the precursors, with a decrease in both Fe and P levels as the titanium doping concentration increased. Moreover, as the titanium content increased, the particle size of the precursor decreased, and the particle distribution became more uniform. Additionally, titanium doping improved the tap density of the precursors, with a significant increase in tap density observed when the titanium content reached 4000 ppm. Electrochemical measurements revealed that titanium doping had a certain impact on the discharge capacity of LiFePO₄, with the discharge capacity gradually decreasing as the titanium content increased. Overall, this study effectively improved the physical properties of LiFePO₄ materials by introducing titanium during the precursor synthesis stage, providing a theoretical foundation for further optimization of titanium-doped LiFePO₄. Full article

The development of hydrometallurgical recycling processes for lithium-ion batteries is challenged by the heterogeneity of the electrode powders recovered from end-of-life batteries via physical methods. These electrode materials, known as black mass, vary in composition, containing differing amounts of nickel, manganese, and cobalt (NMC), as well as other chemicals, such as lithium iron phosphate (LFP). This study presents the results of the hydrometallurgical treatment of mixed NMC and LFP black masses aimed at creating flexible recycling processes. This approach leverages the reducing power of LFP to optimize the leach liquor composition for re-synthesizing NMC precursors. In particular, the leaching conditions were optimized based on the LFP content in the solid feed to maximize the extraction of key metals (Ni, Mn, Co, and Li). The leaching solid residue, graphite, was treated and characterized as a secondary raw material for new anode preparation. Iron phosphate was recovered by increasing the pH of the leach liquor, and the NMC precursors were obtained via coprecipitation. This process achieved a recycling rate of 51%, based on the black mass input and the mass of recovered elements in the output products. Additionally, substituting LFP scraps as the reducing agent in place of H₂O₂ reduced the recycling process’s environmental impact by avoiding 1.7 tons of CO₂-equivalent emissions per ton of NMC black mass. Full article

L-cysteine, a precursor of essential components for plant growth, is synthesized by the cysteine synthase complex, which includes O-acetylserine(thiol) lyase (OAS-TL) and serine acetyltransferase. In this work, we investigated how S-benzyl-L-cysteine (SBC), an OAS-TL inhibitor, affects the growth, photosynthesis, and oxidative stress of Ipomoea grandifolia plants. SBC impaired gas exchange and chlorophyll a fluorescence, indicating damage that compromised photosynthesis and reduced plant growth. Critical parameters such as the electron transport rate (J), triose phosphate utilization (TPU), light-saturation point (LSP), maximum carboxylation rate of Rubisco (V_cmax), and light-saturated net photosynthetic rate (P_Nmax) decreased by 19%, 20%, 22%, 23%, and 24%, respectively. The photochemical quenching coefficient (q_P), quantum yield of photosystem II photochemistry (ϕ_PSII), electron transport rate through PSII (ETR), and stomatal conductance (g_s) decreased by 12%, 19%, 19%, and 34%, respectively. Additionally, SBC decreased the maximum fluorescence yield (F_m), variable fluorescence (F_v), and chlorophyll (SPAD index) by 14%, 15%, and 15%, respectively, indicating possible damage to the photosynthetic apparatus. SBC triggered root oxidative stress by increasing malondialdehyde, reactive oxygen species, and conjugated dienes by 30%, 55%, and 61%, respectively. We hypothesize that dysfunctions in sulfur-containing components of the photosynthetic electron transport chain, such as the cytochrome b₆f complex, ferredoxin, and the iron–sulfur (Fe-S) centers are the cause of these effects, which ultimately reduce the efficiency of electron transport and hinder photosynthesis in I. grandifolia plants. In short, our findings suggest that targeting OAS-TL with inhibitors like SBC could be a promising strategy for the development of novel herbicides. Full article

Realizing rechargeable cells with practical energy and power density requires electrodes with high active material loading, a remaining challenge for solid-state batteries. Here, we present a new strategy based on ionogel-derived solid-state electrolytes (SSEs) to form composite electrodes that enable high active material loading (>10 mg/cm², ~9 mA/cm² at 1C) in a scalable approach for fabricating Li-ion cells. By tuning the precursor and active materials composition incorporated into the composite lithium titanate electrodes, we achieve near-theoretical capacity utilization at C/5 rates and cells capable of stable cycling at 5.85 mA/cm² (11.70 A/g) with over 99% average Coulombic efficiency at room temperature. Finally, we demonstrate a complete polymeric solid-state cell with a composite anode and a composite lithium iron phosphate cathode with ionogel SSEs, which is capable of stable cycling at a 1C rate. Full article

The present article introduces a strategy for controlling oxidation and reduction reactions within polymer electrolyte membrane (PEM) networks as a means of enhancing storage capacity through the complexation of dissociated lithium cations with multifunctional groups of the polymer network. Specifically, co-polymer networks based on polysulfide (PS) and polyoxide (PO) precursors, photo-cured in the presence of succinonitrile (SCN) and lithium bis(trifluoro methane sulfonyl imide) (LiTFSI) salt, exhibited ionic conductivity on the order of mid 10⁻⁴ S/cm at ambient temperature in the 30/35/35 (weight %) composition. Lithium titanate (LTO, Li₄Ti₅O₁₂) electrode was chosen as an anode (i.e., a potential source of Li ions) against lithium iron phosphate (LFP, LiFePO₄) cathode in conjunction with polysulfide-co-polyoxide dual polyelectrolyte networks to control viscosity for 3D printability on conformal surfaces of drone and aeronautic vehicles. It was found that the PS-co-PO dual network-based polymer electrolyte containing SCN plasticizer and LiTFSI salt exhibited extra storage capacity (i.e., specific capacity of 44 mAh/g) with the overall specific capacity of 170 mAh/g (i.e., for the combined LTO electrode and PEM) initially that stabilized at 153 mAh/g after 50th cycles with a reasonable capacity retention of over 90% and Coulombic efficiency of over 99%. Of particular interest is the observation of the improved electrochemical performance of the polysulfide-co-polyoxide electrolyte dual-network relative to that of the polyoxide electrolyte single-network. Full article

To investigate the difference between rumen-protected niacin (RPN) and rumen-protected nicotinamide (RPM) in the transcriptome of genes relating to the lipid metabolism of the liver of periparturient dairy cows, 10 healthy Chinese Holstein cows were randomly divided into two groups and fed diets supplemented with 18.4 g/d RPN or 18.7 g/d RPM, respectively. The experiment lasted from 14 days before to 21 days after parturition. Liver biopsies were taken 21 days postpartum for transcriptomic sequencing. In addition, human LO2 cells were cultured in a medium containing 1.6 mmol/L of non-esterified fatty acids and 1 mmol/L niacin (NA) or 2 mmol/L nicotinamide (NAM) to verify the expression of the 10 genes selected from the transcriptomic analysis of the liver biopsies. The expression of a total of 9837 genes was detected in the liver biopsies, among which 1210 differentially expressed genes (DEGs) were identified, with 579 upregulated and 631 downregulated genes. These DEGs were associated mainly with lipid metabolism, oxidative stress, and some inflammatory pathways. Gene ontology (GO) enrichment analysis showed that 355 DEGs were enriched in 38 GO terms. The differences in the expression of these DEGs between RPN and RPM were predominantly related to the processes of steroid catabolism, steroid hydroxylase, monooxygenase activity, oxidoreductase activity, hemoglobin binding, and ferric iron binding, which are involved mainly in lipid anabolism and redox processes. The expressions of FADS2, SLC27A6, ARHGAP24, and THRSP in LO2 cells were significantly higher (p < 0.05) while the expressions of BCO2, MARS1, GARS1, S100A12, AGMO, and OSBPL11 were significantly lower (p < 0.05) on the NA treatment compared to the NAM treatment, indicating that NA played a role in liver metabolism by directly regulating fatty acid anabolism and transport, inflammatory factor expression, and oxidative stress; and NAM functioned more as a precursor of nicotinamide adenine dinucleotide (NAD, coenzyme I) and nicotinamide adenine dinucleotide phosphate (NADP, coenzyme II) to participate indirectly in biological processes such as ether lipid metabolism, cholesterol metabolism, energy metabolism, and other processes. Full article

Geopolymers have emerged as an alternative binding material to Ordinary Portland Cement (OPC). Recently, there has been an increase in studies exploring the synthesis of these materials using acid activation rather than traditional alkaline activation. This approach offers benefits such as good strength at an early age, better thermal properties, and a chemical activator that emits less carbon to be produced. In addition, it provides resistance to efflorescence and leaching, which are common challenges associated with alkali-activated products. This work analyzed the scientific advances in acid activation in synthesizing an alternative binder to OPC. To this end, a systematic review of the last five years of scientific literature was carried out using the Systematic Review for Engineering and Experiments (SREE) method. The results show a notable increase in research focused on acid activation over the last few years. The acid activators were always phosphate solutions, mainly phosphoric acid. Metakaolin was the most tested precursor, followed by fly ash, and volcanic ash. The research requires improvements in the methodological quality, providing data on molar ratios (Al/P, Si/Al, and Si/P), Liquid/Solid mass ratio, activator solution molarity, and curing process, in addition to statistical treatment and comparison of results. There exists a paucity of diversity in the examined precursors, activators, and additives. Future research developments need to clarify the behavior of mechanical resistance over time, better curing process, water resistance, durability, and the role of iron, magnesium, and calcium silicates and/or oxides. The paper identifies the main research gaps in the area and functions as a database, guiding researchers in selecting raw materials, dosing methodology, and curing processes. Full article

In view of the current situation wherein acid resources and valuable components in titanium dioxide waste acid cannot be effectively extracted and are prone to secondary pollution, our research team proposed a new technique consisting of step extraction and the comprehensive utilization of titanium dioxide waste acid. In this paper, the thermodynamics of selective precipitation and the preparation of doped iron phosphate from waste acid were studied. The thermodynamics results show that the content of Al³⁺, Mn²⁺, Mg²⁺, and Ca²⁺ in the reaction system can be tuned by adjusting the pH during the pre-precipitation process. In the first step, these impurity ions should be settled as much as possible; then, Fe²⁺ should be oxidized to Fe³⁺ so as to obtain iron phosphate with higher purity in the next step of the precipitation process. The effects of the reaction temperature, seed crystals, pH value, and P/M on the precipitation process were investigated in detail. The experimental results show that in the reduced state, the optimal precipitation conditions are a temperature of 75 °C, an initial pH value of 4.5, and an optimal P/M molar ratio of 1.1. In the oxidized state, the optimal precipitation conditions are a temperature of 60 °C, a solution pH = 2.5, and a reaction time of 25 min. After calcination, the precipitate mainly consists of iron phosphate, which basically meets the requirements of an iron phosphate precursor. Full article

With the rapid increase in demand for high-energy-density lithium-ion batteries in electric vehicles, smart homes, electric-powered tools, intelligent transportation, and other markets, high-nickel multi-element materials are considered to be one of the most promising cathode candidates for large-scale industrial applications due to their advantages of high capacity, low cost, and good cycle performance. In response to the competitive pressure of the low-cost lithium iron phosphate battery, high-nickel multi-element cathode materials need to continuously increase their nickel content and reduce their cobalt content or even be cobalt-free and also need to solve a series of problems, such as crystal structure stability, particle microcracks and breakage, cycle life, thermal stability, and safety. In this regard, the research progress of high-nickel multi-element cathode materials in recent years is reviewed and analyzed, and the progress of performance optimization is summarized from the aspects of precursor orientational growth, bulk phase doping, surface coating, interface modification, crystal morphology optimization, composite structure design, etc. Finally, according to the industrialization demand of high-energy-density lithium-ion batteries and the challenges faced by high-nickel multi-element cathode materials, the performance optimization direction of high-nickel multi-element cathode materials in the future is proposed. Full article

5-Aminolevulinic acid (5-ALA) has recently received much attention for its wide applications in medicine and agriculture. In this study, we investigated the effect of NCgl0580 in Corynebacterium glutamicum on 5-ALA biosynthesis as well as its possible mechanism. It was found that the overexpression of NCgl0580 increased 5-ALA production by approximately 53.3%. Interestingly, the knockout of this gene led to an even more significant 2.49-fold increase in 5-ALA production. According to transcriptome analysis and functional validation of phenotype-related targets, the deletion of NCgl0580 brought about considerable changes in the transcript levels of genes involved in central carbon metabolism, leading to fluxes redistribution toward the 5-ALA precursor succinyl-CoA as well as ATP-binding cassette (ABC) transporters affecting 5-ALA biosynthesis. In particular, the positive effects of enhanced sugar transport (by overexpressing NCgl1445 and iolT1), glycolysis (by overexpressing pyk2), iron uptake (by overexpressing afuABC), and phosphate uptake (by overexpressing pstSCAB and ugpQ) on 5-ALA biosynthesis were demonstrated for the first time. Thus, the transcriptional mechanism underlying the effect of NCgl0580 deletion on 5-ALA biosynthesis was elucidated, providing new strategies to regulate the metabolic network of C. glutamicum to achieve a further increase in 5-ALA production. Full article

Phosphates in high concentrations are harmful pollutants for the environment, and new and cheap solutions are currently needed for phosphate removal from polluted liquid media. Iron oxide nanoparticles show a promising capacity for removing phosphates from polluted media and can be easily separated from polluted media under an external magnetic field. However, they have to display a high surface area allowing high removal pollutant capacity while preserving their magnetic properties. In that context, the reproducible synthesis of magnetic iron oxide raspberry-shaped nanostructures (RSNs) by a modified polyol solvothermal method has been optimized, and the conditions to dope the latter with cobalt, zinc, and aluminum to improve the phosphate adsorption have been determined. These RSNs consist of oriented aggregates of iron oxide nanocrystals, providing a very high saturation magnetization and a superparamagnetic behavior that favor colloidal stability. Finally, the adsorption of phosphates as a function of pH, time, and phosphate concentration has been studied. The undoped and especially aluminum-doped RSNs were demonstrated to be very effective phosphate adsorbents, and they can be extracted from the media by applying a magnet. Full article