Ball Milling Method Research Articles

A Rapid Synthesis of Amorphous LiTaOCl4 Solid Electrolytes Through a Two‐Step Reaction Pathway for High‐Rate and Long‐Cycling Lithium Batteries

AbstractA simplified process to prepare solid electrolytes (SEs) that fulfill long cyclability, fast‐charging performance, and wide‐temperature feasibility in all‐solid‐state lithium batteries (ASSLBs) is important. Here, amorphous LiTaOCl4 (aLTOC) SE is synthesized within only four hours via a two‐step reaction by high‐energy ball milling method, which exhibits high ionic conductivity and excellent interfacial compatibility. A bilayer SE based on aLTOC and sulfide along with corresponding ASSLBs, are constructed. Furthermore, slight evolution of the unusual microstructure in the chloride/sulfur interfacial region is observed and analyzed. Density functional theory calculations show that S tends to displace O sites in TaO2Cl4 octahedra instead of Cl sites. As a result of the enhanced interfacial stability and reduced formation of ionically insulating phases, the assembled ASSLBs achieve superior rate performance and cyclability in a wide temperature range. Notably, the ASSLBs show capacity retention of 84.4% and 77.6% after 2000 and 1000 cycles at current density of 10C at 30 and 60 °C, respectively. Importantly, even under −20 °C, the cell works stably over 1600 cycles with capacity retention of 76.3% at 0.5C. The work pave the way for the massive production of high‐performance amorphous chloride electrolytes and the realization of fast‐charging ASSLBs with long cycle life.

Investigation of Microhardness, Microstructural, Tribological, and Thermal Properties of Al7075/TiO2/Kaoline Hybrid Metal Matrix Composites Produced by Powder Metallurgy Process

The shift from traditional, single‐component metals and alloys continues, and researchers are currently investigating alternative materials. This evolution has led to the creation of innovative materials, including hybrid metal‐matrix composites. The present study aims to investigate the microstructural, surface morphological, and thermal properties of a novel Al7075/TiO2/Kaoline hybrid metal‐matrix composite prepared using high‐energy ball milling and sintering methods. In this study, phases related to the composite components are formed depending on the milling time, no undesirable phase is formed, but the peak intensities decreas as the milling time increases. Particle size increases from 63 to 215 μm with increasing milling time. Increasing the kaoline reinforcement ratio and sintering temperature increases the microhardness from 62.27 ± 2 to 75.83 ± 2 HV, and reduces the friction coefficient from 0.82 ± 0.01 to 0.62 ± 0.01. The wear rate of the composite without kaoline addition is 2.1 (mm3 m−1) × 10−3, while with 6 wt% kaoline addition, it decreases to 1.5 (mm3 m−1) × 10−3. There are no cracks in the composite other than plastic deformation due to sintering and wear. Peaks indicating endothermic and exothermic reactions during continuous heating occurr in the 635–750 °C temperature range.

Enhancements in Hydrogen Storage Properties of Magnesium Hydride Supported by Carbon Fiber: Effect of C–H Interactions

Carbon-based materials with excellent catalytic activity provide new ideas for the development of magnesium-based hydrogen storage. C-H bonding interactions may play a key role in performance improvement. In this work, we comprehensively compare the magnesium-carbon cloth composites (CC) prepared by method of dry ball milling and wet impregnation. The results were that the hydrogen release activation energy (Ea) of MgH2@CC composites prepared by wet immersion method was 175.1 ± 19.5 kJ·mol−1, which was lower than that of pure MgH2 (Ea = 213.9 ± 6.4 kJ·mol−1), and the activation energy of MgH2-CC composites prepared by ball milling method was 137.3 ± 8.7 kJ·mol−1, which provided better results. The kinetic enhancement should be attributed to C-H interactions. The presence of carbon carriers and electron transfer to reduce the activation energy of Mg-H bond fracture. These results will provide further insights into the promotion of hydrogen ab-/desorption from metal hydrides.

General Synthesis of High-Entropy Oxides and Carbon-Supported High-Entropy Oxides by Mechanochemistry.

High-entropy oxides (HEOs) have been receiving a lot of attention due to their excellent properties. However, current common methods for preparing HEOs usually involve high-temperature processes. The development of green synthesis techniques remains an important issue. Carbon-supported HEOs have shown excellent performance in electrochemical energy storage in recent years. Crucially, the traditional methods cannot synthesize carbon-supported HEOs under N2 or air atmospheres. Toward this end, a universal method for preparing carbon-supported HEOs was proposed. During this process, without high-temperature post-treatment, high-entropy LaMnO3 could be synthesized in 2 hours using the mechanical ball-milling method. Furthermore, this method was universal and has been proved in the synthesis of a series of HEOs such as PrVO3, SmVO3, and MgAl2O4. The LaMnO3 species synthesized by this method exhibit excellent catalytic performance in CO combustion and could maintain a conversion rate of over 97 % for 350 hours. Subsequently, carbon-supported HEOs could be obtained with 0.5 hours of additional ball-milling, offering significant advantages over traditional methods. This process provides a potential method to synthesize carbon-supported HEOs.

Effective periodate activation by the ball-milled bimetallic zero-valent iron/manganese oxides catalyst for sulfamethoxazole degradation

Developing a green and efficient catalyst for oxidant activation to tackle refractory organics pollution is challenging for water purification. In this study, we prepared a zero-valent iron-based bimetallic catalyst (ZVI/Mn3O4) for periodate (PI) activation using a simple and convenient ball-milling method. Electrochemical characterization and theoretical calculations confirm that the synergy between Fe and Mn enables the ZVI/Mn3O4 system to exhibit higher electron transfer efficiency compared to its individual components. Consequently, the ZVI/Mn3O4/PI system demonstrated enhanced PI activation and significantly improved removal of sulfamethoxazole (SMX), with reaction rates being 18.61 to 57.01 times higher than the comparison systems. The influence of various physicochemical parameters on SMX removal was investigated, confirming the wide tolerance ZVI/Mn3O4/PI system towards multiple aqueous matrices. Furthermore, the scalability of this system for industrial applications was validated through the preparation of larger batches of catalysts (4.21 g per batch) and testing in a custom-designed magnetic plate continuous-flow reactor. Quenching experiments and electron spin resonance tests confirmed that •O2– and 1O2 were the primary reactive species responsible for SMX degradation, with no toxic iodine byproducts detected, attributed to the carefully designed catalyst, which optimized the interaction between PI and the catalyst. Based on these findings, a potential catalytic mechanism and degradation pathway were proposed, highlighting ZVI's role as an electron pump to enhance Mn3O4's activation of PI. Additionally, toxicity assessments via prediction, zebrafish cultivation, wheat germination, and E. coli culture confirmed the excellent detoxification capability of ZVI/Mn3O4/PI system for SMX degradation. Overall, this work provides a new research paradigm for the convenient manufacture of ZVI-based catalysts and the development of advanced techniques for PI activation in water purification.

Exfoliation of boron nitride nanosheets by liquid phase method based on deep eutectic solvents and their thermal management application

AbstractBoron nitride had emerged as an innovative thermally conductive filler, garnering increasing attention from researchers. However, there was a need to create new methods for efficiently producing functionalized boron nitride nanosheets with enhanced thermal conductivity and dispersion. In this study, a novel approach was introduced to utilize deep eutectic solvents as additives to facilitate the exfoliation of boron nitride nanosheets. This method offered significant advantages in terms of cost‐effectiveness (low additives level) and high yield (about 60%). Furthermore, the resulting epoxy resin composite material exhibited outstanding thermal conductivity and thermal management properties. The thermal conductivity of EP/d‐BNNS composites reached 1.02 W/mK at 20 wt% d‐BNNS loading. Additionally, the composite material demonstrated good thermal stability and low dielectric properties. This work demonstrated that this proposed approach represents an effective means for the scalable production of boron nitride nanosheets.Highlights The boron nitride nanosheets were obtained by deep eutectic solvents (DES) ball milling method. The exfoliated boron nitride exhibits superior dispersion stability. The thermal conductivity of EP composites is significantly improved.

Manganese nanoparticles catalyzed the formation of mesoporous helical nitrogen-doped carbon nanotubes enabled aldosterone biosensing

Primary aldosteronism (PA) is the foremost form of secondary hypertension that affects 5–20 % of healthy humans via the excessive secretion of aldosterone (ALD), which increases the level of potassium excretion and thus produces various critical combined diseases. Thus, determining trace-level ALD content in human blood or urine samples is a crucial factor in diagnosing a life-threatening disease called PA. Herein, nanosized manganese particles encapsulated within the tunable helical-shaped N-doped mesoporous carbon nanotubes (Mnx@H-NCNTs) are synthesized by a simple and facile ball-milling method at different reaction times (1, 6, 12, and 18 h). The influence of ball-milling process time on the final morphology of the as-synthesized Mnx@H-NCNTs nanostructures is systematically investigated. In order to fabricate an ALD biosensor electrode, the immobilization of Anti-ALD antibodies (Anti-ALD) on the surface of the Mn@H-NCNTs-12H electrode (Anti-ALD/Mn@H-NCNTs-12H) is achieved via the interactions of combined interactions of hydrogen bonds, Van der Waals’ force, negatively charged carboxylic acid functionalities of antibodies and positively charged metal centers, and π-π stacking interaction between nucleosides of Anti-ALD and mesoporous H-NCNTs. In addition, BSA was used as a blocking additive for covering non-specific adsorption sites of Anti-ALD/Mnx@H-NCNTs (BSA/Anti-ALD/Mn@H-NCNTs-12H) nanostructured electrodes. The BSA/Anti-ALD/Mn@H-NCNTs-12H can be used as an effective signal amplifying probe for ALD detection through a noticeable reduction in the amperometric i-t current response over a linear range from 1 to 2500 pM, with a LOD of 0.72 pM (S/N = 3). The practical applicability of BSA/Anti-ALD/Mn@H-NCNTs-12H is further demonstrated by the detection of ALD from 1 to 20 nM in human blood or urine samples with a recovery ranging from 90.5 to 97.0 %, indicating its potential use in clinical analysis.

Interface-driven microwave absorption enhancement in Mn-optimized Co2FeAl1-xMnx Heusler alloys

To address the urgent need for efficient and stable electromagnetic wave absorbing materials for electromagnetic interference (EMI) protection, we synthesized Co2FeAl1−xMnx Heusler soft magnetic alloys using a high-energy planetary ball milling method. We comprehensively analyzed their structural characteristics, surface morphology, magnetic properties, and electromagnetic parameters to explore their potential in electromagnetic wave absorption. The results show that incorporating manganese (Mn) significantly changes the alloys' crystal structure, surface morphology, and magnetic properties, greatly enhancing their wave absorption performance. The Mn doping specifically alters the surface morphology, which plays a crucial role in influencing the wave absorption characteristics of the Heusler alloys. When the Mn content increased to 25 %, the sample exhibits superior wave absorption, achieving the maximum reflection loss of −44.83 dB at 13.68 GHz with a thickness of 1.5 mm and an effective absorption bandwidth of 5.52 GHz. With a significant increase in the aspect ratio and noticeable changes in surface morphology, the sample with 75 % Mn content shows exceptional performance with an effective absorption bandwidth of 5.68 GHz, representing the highest effective absorption bandwidth in single-phase Heusler alloys. The Mn doping strategy effectively improves the material's impedance matching by adjusting its permittivity and permeability, facilitating multiple polarization relaxation mechanisms and significantly enhancing the alloys' electromagnetic wave absorption efficiency. Our study provides detailed experimental data for optimizing the electromagnetic wave absorption characteristics of Heusler alloys, verifies their practical application potential, and paves the way for developing new high-performance electromagnetic wave absorbing materials.

A composite anode based on intercalation and conversion mechanism for high-rate lithium-ion batteries

To increase the specific capacity and cycle stability of lithium-ion batteries at high current density, we have investigated the anode materials. Among them, black phosphorus has attracted attention because of its large theoretical specific capacity (2596 mA h/g). However, the moderate conductivity of black phosphorus itself makes it less effective. The addition of graphite to form P-C and P-O-C bonds with black phosphorus enhances the performance of the battery cell. Lithium ions are primarily stored in black phosphorus-graphite layered structural materials via an intercalation mechanism, which improves electrochemical performance at tiny current density but is inadequate for charge/discharge cycling at high current density. In addition, lithium ions also can undergo conversion mechanism with metal oxide materials (e.g. Tungsten trioxide). While this conversion mechanism enables more stable battery cycling at high current density, the specific capacity remains insufficiently high. Higher charge/discharge specific capacity and long cycle stability of lithium-ion batteries at high current density can be realized by the joint action of the two mechanisms. In this work, black phosphorus, graphite, and tungsten trioxide (BP/G/WO3) composites are prepared by ball milling method. A comprehensive series of electrochemical analyses reveals that the BP/G/WO3-532 electrode (BP, graphite, and WO3 mass ratio of 5:3:2) exhibits the most substantial enhancement in the cycling stability of lithium-ion batteries. The anode exhibits a high specific capacity of 1463.1 mA h/g at 6 A/g and presents a retention capacity of 1159.8 mA h/g after 300 charge/discharge cycles, indicating a high cycle stability and fast reaction kinetics. This result is mainly attributed to the joint action of two mechanisms of composites.

Reinforcement of recycled polypropylene by nano lanthana with improved thermal, mechanical and antimicrobial properties

Abstract In this study, lanthanum oxide (La2O3) nanoparticles or lanthana were synthesized by the planetary ball milling method and then used as a filler for the preparation of the polypropylene (PP) based nanocomposites by solution mixing method. The PP used in the study was derived from the discarded saline bottles. The structural and the surface morphology of the synthesized lanthanum oxide nanoparticles were characterized by XRD, SEM and FTIR. The thermogravimetric analysis (TGA) study revealed that the thermal stability of the nano lanthana composites increased with the addition of the lanthanum oxide nanoparticles. The mechanical properties, such as Young’s modulus and tensile strength, were also improved by the addition of the lanthanum oxide nanoparticles to the PP matrix. The composites also showed antibacterial activity against Escherichia coli bacteria. This approach not only mitigates medical plastic waste and environmental impact but also paves the way for versatile polymer nanocomposites with extensive industrial applications, especially in biomedical packaging.

Effect of SiC doping on microwave absorbing properties of ball-milled carbonyl iron/MoS2 composites

Using MoS2 to prepare novel composite absorbing coatings is an effective strategy to enhance electromagnetic wave absorption. In order to explore the preparation process of large-scale preparation of MoS2 composite absorbing materials, a Fe/MoS2/SiC laminated composite absorbing material was prepared by high-energy ball milling method to realize the absorption of electromagnetic waves. By adjusting the proportion of SiC, SiC, MoS2 and Fe were ball-milled at room temperature for 20 h, and the dielectric properties were improved to achieve good absorbing effect. The microstructure and properties of the materials were measured by XRD, SEM, Raman, XPS, HRTEM, VSM and VNA. The results show that the doping of appropriate amount of SiC reduces the interplanar spacing of MoS2 and increases the edge points, which increases the conductivity of MoS2. MoS2 reduces the number of layers and increases its size and area, which improves the dielectric properties of Fe/MoS2 and optimizes the electromagnetic parameters of the composites. When the ratio (mole) of SiC, Fe and MoS2 is 3:6:2, the best electromagnetic wave absorption effect is obtained, the lowest electromagnetic wave reflection loss is −72.98 dB, and the best bandwidth is 3.04 GHz when the matching thickness is 6.53 mm.

Fabrication of Ag Nanoparticle-Embedded Covalent Organic Frameworks for Oil Gel with Long-Term Stability and High Lubrication Performance.

In previous reports, covalent organic frameworks (COFs) have demonstrated significant potential as lubricant additives. Herein, we embedded Ag nanoparticles in the DT-COF (polycondensation polymer of 2,5-dihydroxyterephthalaldehyde and 4,4',4″-(1,3,5-triazine-2,4,6-triyl) trianiline) matrix via the ball milling method and utilized this composite (Ag@DT-COF) as an additive for supermolecule oil gel. The low molecular weight gelator effectively mitigates the dispersion challenges of COFs in lubricant oil, while the embedded Ag nanoparticles enhance the repairing effect and antipressure performance of the lubricant. The resulting Ag@DT-COF gel exhibits a reduction in the average friction coefficient and wear volume of base oil by 46.0% and 87.5%, respectively, and increases the load-carrying capacity to 750 N. The remarkable tribological properties are attributed to the easy adsorption of DT-COF, antiwear characteristic of Ag nanoparticles, and the gelator that ensures the long-term stability of oil gel.

Nano-reusable CuO-ZnO Catalyzed One-Pot Synthesis of 1-Amidoalkyl-2-Naphthols under Green Condition

Introduction: The Developed CuO-ZnO nanocomposite has been demonstrated as a new and environmentally friendly catalyst for one-pot multicomponent reaction between aldehydes, 2- naphthol and amides in the synthesis of 1-amidoalkyl-2-naphthols. Method: The new catalyst was synthesized by a ball-milling method by mixing a mixture of CuO and ZnO powder in various proportions and characterized by different spectroscopic methods such as powder X-ray diffraction (pXRD), Scanning Electron Microscopy (SEM), UV-Visible analysis, EDAX elemental analysis and mapping. The advantages of the devised protocol include a green approach, simple work-up procedures, avoidance of hazardous solvents, and good to excellent yields. RE Sult: Evaluation of the catalyst performance in the synthesis of some 1-amidoalkyl-2-naphthols showed presentable results. Sixteen derivatives were synthesized in desirable yield by our new method (4a-4p). CuO-ZnO nanocomposite as a safe and efficient catalyst could be reused up to 5 runs for the synthesis of naphthol derivatives without any significant decrease in its potency. Conclusion: The High purity of the products and desirable yields are other points that make the present work more attractive.

The effect of high-energy ball milling on enhancing the mechanical properties, light transmittance, and thermal shock resistance of bone china porcelain

A bone china grouting slurry was prepared using two different milling methods: low-energy ball milling (Named LBC) for 24 h and high-energy ball milling (Named HBC) for 1 h. Bone china green bodies were formed by grouting, and the dried green bodies were calcined at different temperatures points in the temperature range from 1235 °C to 1255 °C. The slurry characteristics, as well as the structure and properties of the calcined samples, were analyzed and evaluated. The particle sizes of LBC and HBC slurry D50 are 5.819 μm and 3.571 μm, respectively, accounting for 80.4% and 98.7% of their respective proportions. The particle size distribution range of HBC samples was relatively concentrated, and the viscosity of the two slurries was 1040 mPa·s and 2800 mPa·s, respectively. The ball milling method significantly influenced the formation of product phases. The content of calcium feldspar and β-TCP phases in HBC samples calcined at 1245 °C was higher than that in their LBC counterparts, while the quartz content in LBC was higher than that in HBC samples. The water absorption and porosity of the HBC samples were lower than those of the LBC samples, with a flexural strength of 205 MPa, heat shock temperature difference of 190 °C, and light transmittance of 5.18%/3.73 mm, which were 22.4%, 26.7%, and 4.2% higher than those of the LBC samples, respectively. These results indicate that bone china prepared using the high-energy ball milling method exhibits excellent performance.

Study on preparation and properties of GA/h-BN modified road petroleum asphalt based on ball milling method

ABSTRACT Graphene (GA), a two-dimensional nanomaterial, is noted for its exceptional mechanical, thermal and electrical properties. The integration of GA with road materials can potentially develop high-performance composite road materials. However, its application in road engineering is limited by complex preparation processes and high costs. This paper presents a GA/h-BN composite material developed through mechanical stripping using flake graphite and hexagonal boron nitride (h-BN). A mathematical model was created employing uniform design methods and optimised through numerical analysis to identify the optimal process parameters. Microscopic techniques, including X-ray diffraction and atomic force microscopy, confirmed that the GA/h-BN product consists of approximately three layers, forming a ‘graphene-hexagonal boron nitride-graphene’ nanolayer structure. The composite was then used to modify matrix asphalt, with performance tests determining the optimal dosage. The results indicated that adding 0.3% GA/h-BN significantly improved the asphalt's high- and low-temperature performance, fatigue resistance and cracking resistance. Moreover, the evaluation of the physical properties of matrix asphalt modified solely with h-BN revealed that, despite h-BN comprising 70% of the mass fraction in the GA/h-BN modifier, it exerted a minimal impact on the performance of the asphalt. This study introduces a novel source of raw materials for the application of GA in road engineering.

Catalytic modification of MgH2 hydrogen storage properties by La–Ni catalysts

In this paper, it is experimentally demonstrated that the La–Ni catalyst contributes to the hydrogen storage performance of MgH2. Firstly, La–Ni (La: Ni = 1: 5.7) catalysts are prepared by CaH2 reduction method, and then MgH2+x wt.% La–Ni (x = 0, 3, 5, 7) composite alloys were prepared by ball milling method. The present work focuses on the structural and hydrogen ab/desorption properties of the composite alloys, and analysis the modulatory effect and influence mechanism of different La–Ni catalyst additions on the hydrogen storage properties of MgH2. The findings show that the composite alloys have the same diffraction peaks and that the main phase of the composite alloys is the MgH2 phase, with the addition of the LaNi5 phase, the Mg2Ni phase and a small amount of Mg phase. The mutual reversible transformations of LaH3 and Mg2Ni and Mg2NiH4 play a catalytic role in the hydrogen ab/desorption process. Moreover, the addition of La–Ni catalyst plays a dramatic improvement effect on the kinetic performance of MgH2 ab/desorption. When the addition of La–Ni catalyst is 5 wt.%, the composite alloy exhibits the most excellent hydrogen uptake and release kinetics. The MgH2+5 wt.% La–Ni composite alloy absorbs 4.2 wt.% H2 within 2 min at 473 K and releases 3.43 wt.% H2 within 150 min at 503 K. Fitting the hydrogen release activation energy of the composite alloys shows that the hydrogen release activation energy of the composite alloys decreases first and then increases, and there is a minimum hydrogen release activation energy of 101.81 kJ/mol H2 when the addition amount x = 5 wt.%.

Effective reduction of iron impurities in recycled aluminium-silicon alloy type LM-6 through sedimentation and filtration with synthesized Mn, Cr and Zr transition metal powders

Abstract In secondary aluminium recycling, impurity reduction, especially of iron, is a significant challenge as it deteriorates the material quality in the aluminium melt. Recycled aluminium alloys are widely used in various industries, including automotive, marine, and structural engineering. Specifically, LM-6 aluminium alloy is commonly used in automotive engine parts and transmission cases. This research focused on reducing the excessive iron content in LM-6 alloy scrap. Elements like manganese (Mn), chromium (Cr) and zirconium (Zr) were added to the melt in form of synthesized powders to form intermetallic compounds. These powders will also act as grain refiners, neutralizers and reducing the detrimental effects on the alloys. The powders were synthesized using the ball milling method with a ball to powder ratio of (5:1) to enhance mixing and amalgamation with the melt. The melt was held at an optimized temperature of 640 ± 10 °C to promote the formation of intermetallic sludge, encouraging the sedimentation of aluminium-iron (Al-Fe) intermetallic phases. XRD confirmed the formation of AlMn, AlCr, AlZr with other phases. After sedimentation, a glass fabric mesh with a pore size of 200 μm was used to effectively filter out β-iron during the filtration process. This technique reduced iron impurity in the melt by 50%–60%. As a result, the mechanical properties of the recycled aluminium improved significantly: hardness increased by 14%, and tensile strength increased by 36%. The wear and corrosion resistance of the material also improved due to the incorporation of the synthesized powders. SEM analysis revealed the plate-like formation of iron structures and confirmed the presence of the manganese, chromium, and zirconium powders in the metallographic analysis.

Economical Se-doped solid-state electrolytes for sodium-ion symmetric batteries

Solid electrolytes, a key component of all solid-state ion batteries, have gained considerable attention for their high safety and chemical stability. Glass-ceramic electrolyte Na3SbS3.6Se0.4 with no grain boundary impedance was obtained through the ball milling method. An ionic conductivity of up to 3.13 m S/cm and a low activation energy of 0.155 eV were realized. It benefited from the partial replacement of S (1.84 Å) by Se (1.98 Å), which has a larger ionic radius than the former, resulting in larger crystals and wider sodium ion migration channels. Na3SbS3.6Se0.4 achieved a large critical current density of 1.443 mA/cm2 and was stable in contact with the anode of the sodium metal sheet. Furthermore, the electrolyte released only 0.046 cm3/g of H2S in a conventional humidity environment for 30 min, which is lower than the 0.09 cm3/g of H2S released by undoped Na3SbS4. All these excellent properties suggest that the designed electrolyte Na3SbS3.6Se0.4 has a high application potential for sodium ions solid batteries.

Development of the Diffusive Gradient in Thin Film (DGT) Method with CaO/Biochar Binding Agent from Eggshells and Rice Straw Waste for Determining the Concentration of Phosphate

Phosphorus, often found in the form of phosphate in the environment, especially aquatic environments, has been identified as the primary contaminant that causes algae blooms and eutrophication. Phosphate adsorption in the aquatic environment was carried out by comparing the adsorption capabilities of eggshell (CaO), rice straw (BC) and CaO/biochar materials at mass variations of 1:1, 1:2 and 2:1 from the use of eggshell and rice straw waste. Each material was synthesized using ball milling and pyrolysis methods. The adsorption isotherm and kinetics of the material are by the Langmuir adsorption isotherm and are pseudo-second-order (PSO) adsorption kinetics. The CaO/biochar 1:2 material shows the highest phosphate adsorption capacity at pH 12 with a contact time of 24 hours. CaO/biochar 1:2 was applied in the phosphate adsorption process using the Diffusive Gradient in Thin Film method as a binding agent, which acts as an adsorbent. The DGT technique is an in situ sample preparation technique for identifying the presence of phosphate, a labile species. The binding agent material was characterized using FTIR, XRD, and BJH-BET instruments. The success of synthesizing CaO/biochar 1:2 binding gel and ferrihydrite was demonstrated by the appearance of the same adsorption as the diffusive gel using FTIR. The CaO/biochar binding gel demonstrated that it is a better material compared to the ferrihydrite binding gel for phosphate adsorption, achieving CDGT values of 10.1727 mg/L and 2.5959 mg/L at pH 5 and 3, respectively, with a phosphate concentration of 10 mg/L. These findings underscore the potential of CaO/biochar as a more effective material for phosphate removal applications.

Elimination of cracks in Al–Zn–Mg–Cu alloy by addition of TiO2 in selective laser melting

7050 aluminium alloy is widely used in aerospace industry due to its excellent mechanical properties. 7050 aluminium alloy belongs to Al–Zn–Mg–Cu alloy. Due to the formation of cracks in selective laser melting (SLM) forming of Al–Zn–Mg–Cu alloys, 7050 aluminium alloy is difficult to be applied to forming and manufacturing in this technological field. In order to solve this critical problem, in this paper, titanium dioxide (TiO2) powder was mixed with 7050 aluminium alloy using ball milling method to achieve the effect of eliminating cracks. The cracks in the specimens completely disappeared when the TiO2 additions were 1.5 wt% and 2 wt%. With the addition of TiO2, the grains gradually changed from coarse columnar crystals to fine equiaxed crystals. Combined with the temperature field simulation, the grain refinement and crack elimination mechanism of TiO2 in SLM forming were analysed. The grain refinement is attributed to the formation of Al3Ti. The crack elimination was attributed to the reduction of the intergranular solid-liquid channel length. The maximum values of tensile strength and elongation of 7050 aluminium alloy formed by SLM are achieved at 2 wt% of TiO2. The values are 389 MPa and 8.8 %. The better mechanical properties were attributed to the synergistic effect of crack elimination, Hall-Petch, and Orowan strengthening. This study provides experimental guidance for the preparation of crack-free 7050 aluminium alloy.