Search

This research investigates the potential of mechanosynthesis to transform inert waste mixtures into sustainable construction materials. Three waste streams were employed: recycled glass, recycled concrete, and excavated soils. Two alternative material formulations, F1 (50% recycled concrete, 30% recycled glass, 20% excavated soil) and F2 (60% excavated soil, 20% recycled concrete, 20% recycled glass), were developed. Cement pastes were produced by partially substituting cement (CEM I) with 50% of either F1 or F2. Characterization techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (ATR-FTIR), and mechanical testing, were performed. Cement pastes incorporating milled waste materials exhibited significantly enhanced compressive strength compared to their unmilled counterparts. At 28 curing days, compressive strengths reached 44, 47, 45, and 49.7 MPa, and at 90 curing days, they increased to 47.5, 50, 55, and 61 MPa for milling conditions of 200 rpm for 5 min, 200 rpm for 15 min, 400 rpm for 5 min, and 400 rpm for 15 min, respectively. In addition, F1 formulations showed higher compressive strengths than the reference CEM II and CEM III pastes. These results highlight the efficacy of mechanosynthesis in valorizing construction waste, mitigating CO2 emissions, and creating environmentally friendly construction materials. [ABSTRACT FROM AUTHOR]

This study compares the structural, microstructural, thermal, and mechanical properties of geopolymer pastes (GPs) created through traditional methods and those derived from ready-to-use powders for geopolymer (RUPG) materials. The metakaolin (MK) precursor was activated using a sodium silicate solution or CaO and MOH (where M is Na or K). Various ratios of precursor/activator and Na2SiO3 or CaO/MOH were tested to determine the optimal combination. For RUPG, the MK precursor was activated by replacing the sodium silicate solution with quicklime. Metakaolin, alkaline hydroxide, and quicklime powders were mixed at different CaO ratios (wt%) and subjected to extensive ball milling to produce RUPG. The RUPG was then hydrated, molded, and cured at 20 °C and 50% relative humidity until testing. Analytical methods were used to characterize the raw and synthesized materials. Classic geopolymers (CGPs) activated with quicklime burst after one hour of molding. The results indicated slight amorphization of GP compared to raw MK, as confirmed by X-ray diffraction analysis, showing N(K)-A-S-H in CGP and N(K)-A-S-H with calcium silicate hydrate (C-S-H/C-A-S-H) in RUPG. The compressive strength of MK-based geopolymers reached 31.45 MPa and 34.92 MPa for GP and CGP, respectively, after 28 days of curing. [ABSTRACT FROM AUTHOR]

Lead‐free metal halide perovskites can potentially be air‐ and water‐stable photocatalysts for organic synthesis, but there are limited studies on them for this application. Separately, machine learning (ML), a critical subfield of artificial intelligence, has played a pivotal role in identifying correlations and formulating predictions based on extensive datasets. Herein, an iterative workflow by incorporating high‐throughput experimental data with ML to discover new lead‐free metal halide perovskite photocatalysts for the aerobic oxidation of styrene is described. Through six rounds of ML optimization guided by SHapley Additive exPlanations (SHAP) analysis, BA2CsAg0.95Na0.05BiBr7 as a photocatalyst that afforded an 80% yield of benzoic acid under the standard conditions is identified, which is a 13‐fold improvement compared to the 6% with when using Cs2AgBiBr6 as the initial photocatalyst benchmark that is started. BA2CsAg0.95Na0.05BiBr7 can tolerate various functional groups with 22 styrene derivatives, highlighting the generality of the photocatalytic properties demonstrated. Radical scavenging studies and density functional theory calculations revealed that the formation of the reactive oxygen species superoxide and singlet oxygen in the presence of BA2CsAg0.95Na0.05BiBr7 are critical for photocatalysis. [ABSTRACT FROM AUTHOR]

Nowadays high entropy carbides (HECs) are an important group of advanced ceramics. They are composed by at least by five transition metals (TMs) in nearly equiatomic proportion and disordered distributed in the cationic sublattice of face centered cubic structures, with carbon atoms in the octahedral interstitial voids, with general formula (TM1,TM2,TM3,TM4,TM5)C. These HECs belong to the recent novel group of ultra-high temperature ceramics (UHTCs), with superior properties in comparison with the constituent binary carbides. However, the synthesis of those HECs can be modified to develop high entropy carbonitrides, HECNs, where the C are partially substituted by N, to form a solid solution in the anionic sublattice, with expected improved properties as UHTCs, but they are in an incipient state of development. Here, we report the synthesis and deep characterization of a non-previously obtained Hf 0.2 Nb 0.2 Ta 0.2 V 0.2 Zr 0.2 C 0.5 N 0.5 HECN, via a facile, single step and reproducible solid-gas reaction mechanosynthesis route. The synthesis was successfully completed in a planetary ball mill device, after 2h of milling time, at 400 rpm and using a ball-to- powder ratio of 60:1 in a pure N 2 atmosphere at room temperature. The as-synthesized HECNs powdered showed nanostructured morphology and outstanding high-temperature oxidation resistance up to 1500 °C. [ABSTRACT FROM AUTHOR]

This article details work performed on the synthesis and characterization of an inorganic mixed‐cation double halide perovskite, Cs2Ag.6Na.4In.85Bi.15Cl6 (CANIBIC). Single crystals have been created via a hydrothermal reaction, milled into a powder, and pressed into pellets, while nanocrystals have been directly synthesized via mechanosynthesis. A computational model is constructed to predict the X‐ray diffraction pattern of CANIBIC; this model aligns very well with the X‐ray diffraction pattern measured for CANIBIC crystal powder. This model can therefore be developed in the future as a tool to predict lattice parameters and crystal structures of other novel double‐halide perovskites. Photoluminescence spectra obtained from each format show broad emission centered at 630 nm, as is typical for self‐trapped exciton emission; self‐trapped exciton emission is also confirmed by investigating photoluminescence intensity as a function of laser power. Nanocomposites are produced via the loading of nanocrystals of CANIBIC into PMMA. Although nanocomposite disks consisting of a small proportion of CANIBIC nanocrystals in PMMA have a smaller mass attenuation coefficient than a pressed pellet of CANIBIC, these disks have comparatively bright radioluminescence due to their optical transparency. These nanocomposite disks are therefore a particularly useful format for the practical use of the CANIBIC scintillator. [ABSTRACT FROM AUTHOR]

Herein, thermodynamic assessment is proposed to screen suitable precursors for the solid-state synthesis of manganese ferrite, by mechanosynthesis at room temperature or by subsequent calcination at relatively low temperatures, and the main findings are validated by experimental results for the representative precursor mixtures MnO + FeO3, MnO2 + Fe2O3, and MnO2 +2FeCO3. Thermodynamic guidelines are provided for the synthesis of manganese ferrite from (i) oxide and/or metallic precursors; (ii) carbonate + carbonate or carbonate + oxide powder mixtures; (iii) other precursors. It is also shown that synthesis from metallic precursors (Mn + 2Fe) requires a controlled oxygen supply in limited redox conditions, which is hardly achieved by reducing gases H2/H2O or CO/CO2. Oxide mixtures with an overall oxygen balance, such as MnO + Fe2O3, act as self-redox buffers and offer prospects for mechanosynthesis for a sufficient time (>9 h) at room temperature. On the contrary, the fully oxidised oxide mixture MnO2 + Fe2O3 requires partial reduction, which prevents synthesis at room temperature and requires subsequent calcination at temperatures above 1100 °C in air or in nominally inert atmospheres above 750 °C. Oxide + carbonate mixtures, such as MnO2 +2FeCO3, also yield suitable oxygen balance by the decomposition of the carbonate precursor and offer prospects for mechanosynthesis at room temperature, and residual fractions of reactants could be converted by firing at relatively low temperatures (≥650 °C). [ABSTRACT FROM AUTHOR]

Cyanide ions are known to be lethal for insects and mammals and harmful for the environment, and new methods for their selective detection are in high demand. Herein, the mechanosynthesis of simple Schiff's bases-based probes S1–S3 for visual detection of CN− anion is reported. These probes were obtained by means of a reaction between isomeric 4,4-, 3,3- and 2,2-diaminobiphenyls and 4-nitrobenzaldehyde under ball milling conditions. The probes showed high selectivity and sensitivity toward CN− anion via a dramatic "yellow-to-dark purple" color change with a detection limit of 26 × 103, 8.7 × 103 and 14 × 103 ppm for S1–S3, respectively. The proposed mechanism of the detection suggests the deprotonation of a proton from an imine moiety, followed by the formation of charge transfer complexes (CTC). [ABSTRACT FROM AUTHOR]

The manganese ferrite has been processed by mechanosynthesis, using reactive siderite and MnO 2 powder mixtures, with and without subsequent heat treatment. Taguchi planning was used to assess the impact of milling conditions (rotational speed and time) and subsequent calcination temperature on conversion of precursors, based on integrated intensities of the main XRD peaks of precursor phases FeCO 3 (104) and MnO 2 (110), and spinel phase (311), using Ni as internal pattern. Thermogravimetry provided additional information on the residual contents of reactants in the as-milled samples. The best conditions for complete conversion to spinel phase of as-milled samples were obtained by milling at 650 rpm, for 6 h ( I 311 , s p / I 111 , N i = 2.41) , and for calcined samples were obtained after milling at 650 rpm, for 3 h, and calcination at 650 °C (I 311 , s p / I 111 , N i = 2.35). The impact of processing conditions on structural features of the spinel phase was accounted by the contributions to variance of intensity of its (311) reflection, which were 90% ascribed to rotational speed and only 4% ascribed to milling time, for as-milled samples, or 58%, 15% and 16% ascribed to rotational speed, milling time and calcination temperature, for calcined samples. Readier conversion of FeCO 3 relative to MnO 2 occurred during the milling stage, at low or intermediate rotational speed, with impact on M n : F e ratio in the spinel phase, as revealed by changes in lattice parameter of as-milled samples, in the range of 0.8424–0.8464 nm. Subsequent calcination minimized or eliminated traces of secondary phases. The incorporation of magnesium oxide and possibly other secondary components of the siderite precursor also induced structural changes in the resulting spinel phase, mainly in calcined samples (a o = 0.8370–0.8434 nm). Partial oxidation also contributed to structural changes in calcined samples, as revealed by differences between samples calcined in inert and oxidising atmospheres. [ABSTRACT FROM AUTHOR]

Rhodamine‐based chromic materials have attracted significant interest owing to their cation recognition ability with high sensitivity. However, rhodamine chromophores with controllable sensing selectivity towards transition metal species are only at the advent. Herein, three triazole‐conjugated rhodamine dyads with different peripheral substituents were synthesized. The key triazole precursors required for the desired chemistry were prepared by adopting our recently developed CTAB catalyzed mechano‐click chemistry. Molecular properties derived from photophysics, electrochemistry and surface morphology of the synthesized dyads were analyzed. Furthermore, frontier molecular orbitals, electronic structure and secondary quantum chemical parameters of dyads were also compared. Screening of dyads for their sensing ability towards an array of alkali, alkaline and transition metal ions exhibited a noticeable naked‐eye detection of Cu2+ ions and was confirmed by spectrophotometric titration. The specific binding mode of dyads as probable with Cu2+ over other metal ions attributes to the chemoselectivity. [ABSTRACT FROM AUTHOR]

Low temperature magnetic properties of BiFeO3 powders sintered by flash and spark plasma sintering were studied. An anomaly observed in the magnetic measurements at 250 K proves the clear existence of a phase transition. This transformation, which becomes less well-defined as the grain sizes are reduced to nanometer scale, was described with regard to a magneto-elastic coupling. Furthermore, the samples exhibited enhanced ferromagnetic properties as compared with those of a pellet prepared by the conventional solid-state technique, with both a higher coercivity field and remnant magnetization, reaching a maximum value of 1.17 kOe and 8.5 10−3 emu/g, respectively, for the specimen sintered by flash sintering, which possesses the smallest grains. The specimens also show more significant exchange bias, from 22 to 177 Oe for the specimen prepared by the solid-state method and flash sintering technique, respectively. The observed increase in this parameter is explained in terms of a stronger exchange interaction between ferromagnetic and antiferromagnetic grains in the case of the pellet sintered by flash sintering. [ABSTRACT FROM AUTHOR]

A green chemistry method was applied in the synthesis of N2,N6-bis(6-iodo-2-methyl-4-oxoquinazolin-3(4H)-yl)pyridine-2,6-dicarboxamide. The desired compound was synthesized mechanochemically, using a choline chloride-based deep eutectic solvent as a catalyst. The synthesis took 20 min and the new compound was characterized using different spectral methods. [ABSTRACT FROM AUTHOR]

Nanostructured materials containing nickel improve the effectiveness of several applications. This study examines the preparation and characterization of nanostructured Ni 80 Co 17 Mo 3 alloy powders using high-energy mechanical alloying and subsequent annealing. A 72 h milling process used pure elemental powders to synthesise nanocrystalline FCC-NiCo(Mo) solid solution. The milled powders were then subjected to annealing at different temperatures:300°C, 500°C, and 750°C. X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy, and vibrating sample magnetometry indicated significant changes in the powdered alloy properties. The particles growth occurred as the annealing temperature increased, while the microstrain decreased significantly; 14.30±0.07 nm up to 56.30±0.28 nm and 0.680±0.003 % up to 0.180±0.001 %, at 25°C and 750°C respectively. SEM analysis revealed differences in particle size and shape as milling progressed. Surprisingly, the milled powdered alloy displayed improved magnetic properties, manifesting significant magnetic susceptibility and enhanced saturation magnetisation, remanent magnetisation, and coercivity within the temperature range of 300°C to 750°C. These findings indicate the development of a consistent and structured state, accompanied by significant crystal growth due to the annealing temperature. This study highlights the great importance of high-energy mechanical milling and subsequent annealing to tune / tailor the characteristics and subsequently investigate the potential utilization of nanostructured Ni-based alloys. [Display omitted] • The Ni80Co17Mo3 solid phase with a face-centred cubic (FCC) structure was generated after 12 h of milling. • Temperature-Induced Microstructural Evolution • The magnetization of Ni80Co17Mo3 decreases gradually with increasing at Elevated Temperatures. • The presence of nanocrystalline defects, namely stacking faults, causes a decrease in Hc. • The nanostructured Ni80Co17Mo3 material has a very pliable magnetic behaviour after it reaches saturation. [ABSTRACT FROM AUTHOR]

Lead-free ferroelectric Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 stands out among environmentally friendly alternatives to commercial Pb(Zr,Ti)O 3 piezoceramics for its large piezoelectric coefficients, and it is especially suitable for applications in which thermal depoling is not an issue like bio-implanted devices. However, ceramic processing by conventional means consistently results in exaggerated grain growth, which compromises reliability and has prevented its transfer to industry. We report here the application of high-energy milling for the mechanosynthesis of nanocrystalline Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 powders with enhanced reactivity, and to the control of grain growth during ceramic processing to obtain materials with tailored microstructures and decreasing grain sizes down to the sub-10 µm range. Characterization of the electrical and electromechanical properties was accomplished and uncovered triggering of a new mechanism for very large strain under electric field in fine-grained ceramics. Process optimization by precursor selection and preliminary up-scaling studies are also presented. [ABSTRACT FROM AUTHOR]

Sugar amides, such as aldonamides, are interesting, sugar-based molecules used in various fields, from detergency to medicine. Nevertheless, their valorization, especially as alternatives to petroleum-based substances, can be slowed down by their synthetic pathway, which is generally not in accordance with green chemistry principles, and is also not economically competitive. We propose herein a fast procedure for the synthesis of aldonamide-derived glycoconjugates with mechanochemistry. The conditions were first optimized with galactonolactone, used as a model lactone, and dodecylamine. After only 5 min of grinding of stoechiometric amounts of amine and lactone, in the presence of water used as a Liquid Assisted Grinding (LAG) agent, the corresponding galactonamide was isolated with a high yield (90%) after a simple aqueous work-up. The optimized conditions were then applied to a wide variety of amines and sugar lactones, showing the versatility of the methodology. Gluco- and ribono-lactone exhibited similarly excellent reactivity, showing that the procedure is not sugar-dependent. Furthermore, the procedure was shown to be compatible with various functional groups such as alkene, alkyne, thiol, ester and hydroxyl. [ABSTRACT FROM AUTHOR]

Mechanochemical synthesis of 2,5-disubstituted 1,3,4-oxadiazoles was developed as an environmentally benign alternative to conventional solvent-based methods. In the presence of triphenylphosphine and trichloroisocyanuric acid, N -acylbenzotriazoles condense with acylhydrazides leading to oxadiazoles derivatives in good to excellent yields within minutes. The approach circumvents the need for strictly anhydrous conditions, external heating, long reaction times, as well as tedious multistep procedures. A range of substrates with reactive functionalities was also well tolerated. [ABSTRACT FROM AUTHOR]

Mechanochemistry uses mechanical force to break, form, and manipulate chemical bonds to achieve functional transformations and syntheses. Over the last years, many innovative applications of mechanochemistry have been developed. Specifically for the synthesis and activation of carbon‐rich π‐conjugated materials, mechanochemistry offers reaction pathways that either are inaccessible with other stimuli, such as light and heat, or improve reaction yields, energy consumption, and substrate scope. Therefore, this review summarizes the recent advances in this research field combining the viewpoints of polymer and trituration mechanochemistry. The highlighted mechanochemical transformations include π‐conjugated materials as optical force probes, the force‐induced release of small dye molecules, and the mechanochemical synthesis of polyacetylene, carbon allotropes, and other π‐conjugated materials. [ABSTRACT FROM AUTHOR]

Rational synthesis of hydrogen‐bonded organic frameworks (HOFs) with predicted structure has been a long‐term challenge. Herein, by using the efficient, simple, low‐cost, and scalable mechanosynthesis, we demonstrate that reticular chemistry is applicable to HOF assemblies based on building blocks with different geometry, connectivity, and functionality. The obtained crystalline HOFs show uniform nano‐sized morphology, which is challenging or unachievable for conventional solution‐based methods. Furthermore, the one‐pot mechanosynthesis generated a series of Pd@HOF composites with noticeably different CO oxidation activities. In situ DRIFTS studies indicate that the most efficient composite, counterintuitively, shows the weakest CO affinity to Pd sites while the strongest CO affinity to HOF matrix, revealing the vital role of porous matrix to the catalytic performance. This work paves a new avenue for rational synthesis of HOF and HOF‐based composites for broad application potential. [ABSTRACT FROM AUTHOR]

Rational synthesis of hydrogen‐bonded organic frameworks (HOFs) with predicted structure has been a long‐term challenge. Herein, by using the efficient, simple, low‐cost, and scalable mechanosynthesis, we demonstrate that reticular chemistry is applicable to HOF assemblies based on building blocks with different geometry, connectivity, and functionality. The obtained crystalline HOFs show uniform nano‐sized morphology, which is challenging or unachievable for conventional solution‐based methods. Furthermore, the one‐pot mechanosynthesis generated a series of Pd@HOF composites with noticeably different CO oxidation activities. In situ DRIFTS studies indicate that the most efficient composite, counterintuitively, shows the weakest CO affinity to Pd sites while the strongest CO affinity to HOF matrix, revealing the vital role of porous matrix to the catalytic performance. This work paves a new avenue for rational synthesis of HOF and HOF‐based composites for broad application potential. [ABSTRACT FROM AUTHOR]

The possibility of obtaining polymer–drug conjugates as prolonged-action antibacterial systems by mechanochemical synthesis using the copolymer of maleic anhydride with vinyl acetate or oxidized potato starch as polymer matrices and sulfanilamide as the antimicrobial drug was studied. It is established that drug conjugation with the polymer results from covalent bonding, the degree of sulfanilamide conversion depends on the magnitude of active force and the time of the solid-phase reaction, and the product continues to accumulate after the load is removed. The conjugate with the polysaccharide matrix, from which the drug release due to cleavage of an azomethine bond was slower than its removal from the body if the initial dosage form was used, was most promising. [ABSTRACT FROM AUTHOR]

In the first stage of this work, the master nanocomposite of niobium carbide (NbC)–Cu (ceramic‐based nanocomposite) was synthesized by a mechanically induced magnesiothermic combustion in the Nb2O5/CuO/Mg/C system. Ignition time in this system was recorded to be ∼28 min of milling. In the second stage, appropriate amounts of NbC–Cu nanocomposite powder were mixed with pure copper powder to prepare Cu‐based nanocomposite with 0, 5, 10, 15, and 20 volume fraction of NbC. The final metal matrix nanocomposite powder was sintered by spark plasma sintering method. The density of nanocomposite specimens decreased with increasing the percentage of NbC nanoparticles, while the microhardness of specimens increased with increasing nano‐NbC content. Regarding the tensile test, the sample Cu–10 vol.% NbC nanocomposite with a strength of 372 MPa (∼63% higher than that of nonreinforced copper) was the best composition, and the nanocomposite strength decreased at higher NbC concentrations, mostly due to the agglomeration and nonhomogeneous distribution of reinforcing nanoparticles. [ABSTRACT FROM AUTHOR]

Different stoichiometries of lead-free BaZr 0.2 Ti 0.8 O 3 –Ba 0.7 Ca 0.3 TiO 3 (BCZT) prepared by mechanosynthesis and sintered by either conventional sintering (CS) or hot pressing (HP) techniques were studied to establish the dependence of piezoelectric and dielectric properties on sintering parameters and microstructure. All synthesized stoichiometries showed a pseudocubic perovskite phase with homogeneously distributed A- and B-cations in the structure. The BCZT retained the pseudocubic symmetry after sintering and an average grain size <1.8 µm was obtained in all cases. HP sintering hindered the secondary phase segregation observed in the CS ceramics and increased the relative density. Piezoelectric coefficients (d 33) ranging from 5.1 to 21 pC/N and from 10.0 to 88.0 pC/N were obtained for CS and HP ceramics, respectively, despite the pseudocubic symmetry and the fine grain size. The higher d 33 values for the HP ceramics are a consequence of the higher density, better chemical homogeneity and lower sintering temperature and time required for the mechanosynthesized BCZT powders with high sintering activity. • BCZT were successfully formed by high-energy mechanosynthesis after 120 min. • Fine-grained BCZT were obtained by either conventional sintering or hot pressing. • HP sintering favored the presence of different crystal structures and higher density. • d 33 values ranged from 5.1 to 88.0 pC/N, depending on stoichiometry and sintering. [ABSTRACT FROM AUTHOR]

• This paper explored mechanosynthesis of anionic-substituted HA nanopowders. • Rietveld refinement was used to describe the structural features. • Insights into how milling time and dopants affect HA crystal structure were provided. • Particle morphology evolution during milling was observed in TEM analysis. • Intermediate phases emerged as a pivotal factor influencing the advancement of reactions. An investigation into the microstructural properties and mechanosynthesis mechanisms of three distinct calcium phosphate compounds, namely, carbonate-substituted hydroxyapatite (CHA), fluorapatite (FA), and carbonate- and fluoride-substituted hydroxyapatite (CFHA), was undertaken in this study. Significant insights into the crystalline structures of CHA, FA, and CFHA were revealed through Rietveld refinement analysis. In the CaCO 3 ‒Ca(OH) 2 ‒P 2 O 5 ternary system, the transformation of the biphasic structure composed of CHA and dicalcium phosphate anhydrous (DCPA) into a single-phase A-type CHA was observed as milling duration increased. In the CaO‒Ca(OH) 2 ‒CaF 2 ‒P 2 O 5 quaternary system, the formation of FA was influenced by milling time, and within 1‒5 h, a composite structure was formed. The progression from a composite structure to the formation of fully crystalline nanosized CFHA was also observed over the same milling periods in the CaCO 3 ‒Ca(OH) 2 ‒CaF 2 ‒P 2 O 5 quaternary system. The central finding highlights the substantial influence of milling time on the structural properties of the mechanosynthesized nanopowders, with marked changes in crystallite size, micro-strain, and unit cell volume being observed over different milling durations. The atomic coordinates and displacement parameters of the refined structures were also provided, revealing the presence of apatitic groups. Moreover, a detailed examination of the mechanochemical synthesis processes uncovered intricate sub-reactions that occur during ball milling. This work sets the stage for future investigations, facilitating a better grasp of their distinctive attributes and potential applications across various domains of regenerative medicine. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Ball milling is a cost-effective, one-step, and solvent-free approach to preparing electrode materials and shows advantages such as no use of heat treatment, harmful solvents, long processes, and high energy consumption required by the common methods such as solvothermal, sol–gel, hydrothermal, and precipitation. • Functional materials applied in supercapacitors can be produced via planetary ball milling. • Transition metal carbonates and nanocomposite were mechanochemically synthesized without additional process. • MnCO 3 and CoCO 3 resulted in excellent performance in 1 M KOH electrolyte. • High storage, remarkable rate capability, and outstanding capacitance retention were achieved. Transition metals are known for their enormous potential as electrode materials for supercapacitor applications, however anhydrous carbonate minerals, namely Mn-carbonate, and Co-carbonate, are less explored and exhibit competitive energy storage performance compared to oxide and hydroxide forms. For the first time, MnCO 3 (Rhodochrosite), CoCO 3 (Spherocobaltite) and MnCo mixture (Mn 1-x Co x CO 3) were synthesized via mechanochemistry by a one-pot approach and used to prepare pseudocapacitive electrode materials for electrochemical energy storage. In this work, these materials were tested in alkaline electrolyte, and the morphological and structural features of the materials were examined using SEM (Scanning Electron Microscope), Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD). The surface composition was studied by X-ray photoelectron spectroscopy (XPS). After milling, the microstructures showed an increase in dislocations and microstrains in their crystal lattices which influenced the electrochemical performance. The crystallinity of the carbonate materials was also affected by grinding. In 1 M KOH electrolyte, milled MnCO 3 evidenced the highest specific capacitance (354.3 F/g at 1.0 A/g), while milled CoCO 3 , revealed impressive capacitance retention of 94.8 % after 20000 continuous charge–discharge cycles at 10 A/g. Interestingly, the composite (Mn-Co)CO 3 evidenced superior rate capability (58.8 %) and enhanced capacitance retention under cycling compared to the individual cobalt and manganese carbonates. The results evidence the excellent electrochemical behavior of Mn and Co carbonates prepared by a simple, low-cost, and green route and prove their potential as electroactive electrode materials for electrochemical energy storage applications, particularly pseudocapacitors. [ABSTRACT FROM AUTHOR]

CdS nanoparticles were successfully synthesized using cadmium acetate and sodium sulfide as Cd and S precursors, respectively. The effect of using sodium thiosulfate as an additional sulfur precursor was also investigated (combined milling). The samples were characterized by XRD, Raman spectroscopy, XPS, UV-Vis spectroscopy, PL spectroscopy, DLS, and TEM. Photocatalytic activities of both CdS samples were compared. The photocatalytic activity of CdS, which is produced by combined milling, was superior to that of CdS, and was obtained by an acetate route in the degradation of Orange II under visible light irradiation. Better results for CdS prepared using a combined approach were also evidenced in photocatalytic experiments on hydrogen generation. The antibacterial potential of mechanochemically prepared CdS nanocrystals was also tested on reference strains of E. coli and S. aureus. Susceptibility tests included a 24-h toxicity test, a disk diffusion assay, and respiration monitoring. Bacterial growth was not completely inhibited by the presence of neither nanomaterial in the growth environment. However, the experiments have confirmed that the nanoparticles have some capability to inhibit bacterial growth during the logarithmic growth phase, with a more substantial effect coming from CdS nanoparticles prepared in the absence of sodium thiosulfate. The present research demonstrated the solvent-free, facile, and sustainable character of mechanochemical synthesis to produce semiconductor nanocrystals with multidisciplinary application. [ABSTRACT FROM AUTHOR]

We apply high energy mechanosynthesis in mixtures of Y2O3 and Fe2O3 to form activated nanostructured oxide composites for subsequent temperature treatment with the aim to synthesize single phase functional Y3Fe5O12 garnet particles. Obtained at the same temperature regime but starting from structurally different precursors, garnet particles demonstrate different magnetic behavior. Mossbauer and Raman spectroscopy were applied for a comprehensive characterization on the local atomic scale the influence of the mechanochemically produced precursor's fine structure formed at different activation duration on the structural and magnetic state of the garnet particles. X-ray diffraction and visualization of fine particles structure by SEM microscopy were supplemented. An intermediate disordered iron oxide phases and orthoferrite YFeO3 rather garnet structure formation at prolonged duration of intense mechanical activation was determined. Magnetic structure of Y3Fe5O12 formed after annealing was dependent on the degree of the oxides interaction in precursors and defects concentrated at the grain boundaries and interfaces. Both applied spectroscopies showed complementary insight into the nature of the local structural disorder at the steps of mechanosynthesis to the mechanism of fine garnet structure formation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mechanosynthesis of hydroxyfluorapatite powder. • Nanoparticles are characterised by XRD, IR, Raman, DLS, BET, SEM, XPS and TEM. • A mathematical model is introduced to analyze the effect of milling parameters. • Experimental results are in agreement with the calculations of the theorical model. • The resulting hydroxyfluorapatite powder exhibits an average grain size of about 10 nm. The nanocrystalline hydroxyfluorapatite (HFA) was synthesized by mechanosynthesis with a planetary ball mill (PM200). The disc to jar speed ratio was constant (equal to 0.5). The effect of different milling parameters such as grinding duration, balls number's, initial powder mass and disc rotation speed were studied to apprehend their effects on both the process of grinding/mechanosynthesis and the synthesis of nanocrystalline HFA. Unlike previous studies in which milling parameters have been independently studied, the effects of these parameters on the phase contents were simultaneously studied. Abdellaoui's model was also introduced to analyse the physical milling parameters effect such as the injected shock power, the shock kinetic energy, the shock frequency and the cumulated kinetic energy on the microstructural properties and synthesized phases contents. The results predicted by the model were compared to experimental ones. This study showed that the optimal conditions for the synthesis of nanocrystalline HFA were reached when the mechanosynthesis was carried out with a speed of 450 rpm, 6 balls, 1.2 g of starting material and 24 h of grinding duration. X-ray diffraction characterization confirmed the purity phase of HFA nanocrystalline powders. [ABSTRACT FROM AUTHOR]

Mechanochemical synthesis of CsPbI3, as a model system for ABX3 halides, was studied. Water was shown to strongly promote the kinetics of formation of CsPbI3 from the CsI+PbI2 mixture through increased mobility of the constituting ionic species. Since many binary and ternary halides are hygroscopic, it was concluded that the presence of small, uncontrollable and unintentional additions of water should often occur in both precursor mixtures and synthesized complex halides boosting the kinetics of formation of many, if not all, ternary organic–inorganic hybrid halides such as, for example, MAPbX3 (X=Cl, Br, I). In addition, trace amounts of water should influence the transport characteristics of complex halides. Thus, the presence of water explains, at least partially, the huge scatter in both the reported mechanochemical reaction times necessary for obtaining single‐phase APbX3 perovskite halides and the activation energies of ionic diffusion in APbX3. [ABSTRACT FROM AUTHOR]

The six possible equiatomic five-transition metal High Entropy Carbides (HECs) of the IVB (Ti, Zr, Hf) and VB (V, Nb, Ta) groups of the periodic table, i.e., TiZrHfVNbC 5 , TiZrHfVTaC 5 , TiZrHfNbTaC 5 , TiZrVNbTaC 5 , TiHfVNbTaC 5 and ZrHfVNbTaC 5 , were successfully obtained via a powder metallurgy route at room temperature, specifically, by one-step diffusion mechanosynthesis starting from the elemental constituents (using graphite as the carbon source). Three of those HECs, TiZrHfVTaC 5 , TiZrVNbTaC 5 and ZrHfVNbTaC 5 , were developed for the first time. Their development was possible without any subsequent thermal treatment, in contrast to the usual way (reactive sintering at 1800–2200 °C), and in a powder form, make them potential advanced raw ceramics for hard, refractory and oxidation resistance coatings or matrix phase composites. [ABSTRACT FROM AUTHOR]

Molybdenum carbide‐based carbon materials were investigated as a catalyst for hydrodeoxygenation (HDO) of guaiacol. Mechanochemical synthesis has been used as a novel approach to obtain a fine molybdenum carbide‐based carbon catalysts. Guaiacol was chosen as a bio‐oil model compound to estimate the potential of the catalysts. The catalytic tests were carried out at 4 MPa initial hydrogen pressure, 320 °C for 180 min in a batch autoclave reactor. Insert abstract text here. A feed mixture was 3.5 g guaiacol in 66.5 g hexadecane as a solvent. [ABSTRACT FROM AUTHOR]

The discovery of molecular ionic cocrystals (ICCs) of active pharmaceutical ingredients (APIs) widens the opportunities for optimizing the physicochemical properties of APIs whilst facilitating the delivery of multiple therapeutic agents. However, ICCs are often observed serendipitously in crystallization screens and the factors dictating their crystallization are poorly understood. We demonstrate here that mechanochemical ball milling is a versatile technique for the reproducible synthesis of ternary molecular ICCs in less than 30 min of grinding with or without solvent. Computational crystal structure prediction (CSP) calculations have been performed on ternary molecular ICCs for the first time and the observed crystal structures of all the ICCs were correctly predicted. Periodic dispersion‐corrected DFT calculations revealed that all the ICCs are thermodynamically stable (mean stabilization energy=−2 kJ mol−1) relative to the crystallization of a physical mixture of the binary salt and acid. The results suggest that a combined mechanosynthesis and CSP approach could be used to target the synthesis of higher‐order molecular ICCs with functional properties. [ABSTRACT FROM AUTHOR]

The present work explores mechanosynthesis of lanthanum aluminate-based perovskite ceramics and corresponding effects on ionic-electronic transport properties. La 1- x Ca x AlO 3-δ (x = 0.05–0.20) nanopowders were prepared via one-step high-energy mechanochemical processing. Sintering at 1450 °C yielded dense ceramics with submicron grains. As-prepared powders and sintered ceramics were characterized by XRPD, XPS and SEM. Electrochemical studies showed that partial oxygen-ionic conductivity in prepared La 1- x Ca x AlO 3-δ increases with calcium content up to 10 at.% in the lanthanum sublattice and then levels off at ∼6 × 10−3 S/cm at 900 °C. La 1- x Ca x AlO 3-δ ceramics are mixed conductors under oxidizing conditions and ionic conductors with negligible contribution of electronic transport in reducing atmospheres. Oxygen-ionic contribution to the total conductivity is 20–68% at 900 °C in air and increases with Ca content, with temperature and with reducing p(O 2). Impedance spectroscopy results showed however that electrical properties of mechanosynthesized La 1- x Ca x AlO 3-δ ceramics below ∼800 °C are determined by prevailing grain boundary contribution to the total resistivity. [ABSTRACT FROM AUTHOR]

A novel, homogeneous, nanostructured and equiatomic (TiZrHfVNb)C 5 High Entropy Carbide (HEC) was successfully synthesised in a powder form by a mechanosynthesis process from the elemental mixture. This synthesis method for HECs, not previously reported, is simple, reproducible and carried out at room temperature. During milling, the transition metals (Ti, Zr, Hf, V and Nb) alloying and the diffusion of carbon (introduced as graphite) into the alloy structure are simultaneously induced, obtaining the expected (TiZrHfVNb)C 5 HEC. The room temperature method employed contrasts with those reported in the bibliography from binary carbides that are carried out at a very high temperature (1800–2200 °C), with the consequent energy savings. [ABSTRACT FROM AUTHOR]

Hydroxyfluorapatite Ca 10 (PO 4) 6 (OH)F (HFA) powders were prepared by mechanosynthesis method using planetary ball milling with various parameters. X-ray Diffraction (XRD), Infrared (IR) and Raman spectroscopies, Energy Dispersive X-ray (EDX) and Brunauer-Emmett-Teller (BET) methods were employed to characterize the synthesized nanoparticles. Four factors (rotation speeds of disk, mass of balls, initial mass of powder and milling time) were investigated to understand their effect on the milling process and the formation of HFA nanocrystallite. Taguchi's design, with just 16 experiments (an L16 orthogonal array), was used to evaluate the impact of these parameters on six distinct properties, namely the crystallite size (nm), the percentage of crystallinity, the specific surface area (m2/g), the Ca/P atomic ratio, the percentages of the apatite and calcite phases. The average effects of the milling parameters and the signal-to-noise ratio (SN) were discussed. ANOVA analysis was used to determine the importance, the proportion of factor participation and also the influence of process parameters on responses. The Taguchi results indicated that the mass of balls and the rotation speed were found to be the most influential factors on the purity of compounds. The ball to powder weight ratio (BPR) was also introduced to study its effect on the synthesis process. Transmission Electron Microscopy (TEM), Scanning Electronic Microscopy (SEM) and Dynamic Light Scattering (DLS) revealed that milled HFA powders contained a nano-sized agglomerate. Unlabelled Image • Taguchi methods was used for synthesis and characterization of hydroxyfluoroapatite. • Nanoparticles were characterized by XRD, IR, Raman, EDX, BET, SEM and TEM. • Impacts of grinding parameters on purity, composition and morphology were studied. • Balls'mass and disk rotation speed show the most effects on purity and Ca/P ratio. • Crystallite size and crystallinity are influenced by rotation speed and powder mass. [ABSTRACT FROM AUTHOR]

Solvent‐assisted ball milling is used to prepare the sulfide solid electrolyte Li7P3S11. Comparing with dry ball milling and simple liquid phase synthesis, solvent‐assisted ball milling can significantly promote the reaction of the starting materials from tens of hours to only several hours. When using dimethoxyethane as the assistant solvent, relatively pure Li7P3S11 with ionic conductivity of 1.0 × 10−4 S/cm can be synthesized after 8‐hour ball milling with following 2‐hour 180°C vacuum drying and 4‐hour 230°C heat treatment. It is revealed that the transition from the precursor to Li7P3S11 is a two‐step process, with an intermediate composed of a thio‐LISICON III analogous phase and an amorphous phase. This work not only provides a synthesis route of Li7P3S11 which reduces synthesis duration, but also offers an instructive insight into the phase evolution in solvent‐based synthesis process of sulfide solid electrolytes. [ABSTRACT FROM AUTHOR]

Highlights • Nanostructured materials obtained by Mechanosynthesis. • Milled co-product increase mechanical performances of substituted cement. • High-energy milling tends to produce more agglomerated particles. • The use of PCA reduce agglomeration phenomena. • Co-products mechanical activation improve pozzolanic reactions. Abstract In this study, we have modified slag and fly ashes by mechanosynthesis process carried out by high-energy ball milling using a planetary mill. In order to optimize the milling conditions, we have added process control agent (PCA). This PCA affects powders agglomeration phenomena during milling and impacts the milling time for the final product. We have studied the structure and microstructure of coproducts (fly ashes and slag) obtained by mechanical activation. In addition, we have also tested the mechanical performances of samples prepared with the addition of activated coproducts. [ABSTRACT FROM AUTHOR]

Abstract The nanoparticles of vanadium, niobium, and tantalum carbides were synthesized by a mechanically induced magnesiothermic combustion in the separate Mg/V 2 O 5 /C, Mg/Nb 2 O 5 /C, and Mg/Ta 2 O 5 /C systems. Initial materials in these systems ignited after short milling times of 10, 10, and 23 min, respectively. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM) and elemental mapping techniques were employed to characterize the combustion products. In this process, magnesium reduces initial oxides to generate elemental V/Nb/Ta to react with carbon, forming the carbide phases. Highlights • Ultra-high temperature ceramics of VC, NbC, and TaC were mechano-synthesized through a magnesiothermic reduction. • High-energy ball milling was used to induce a combustion reaction inside the milling chamber. • The mechanism of the products formation was described. • The carbide compounds were characterized by various techniques. [ABSTRACT FROM AUTHOR]

Abstract The effect of polyvinyl alcohol, PVA, on crystallite and particle sizes of strontium hexaferrite synthesized by high-energy ball milling followed by an annealing at 950 °C is presented. Results of X-ray diffraction of (100-x)SrFe 12 O 19 @xPVA (0 ≤ x ≤ 100) composites shown the presence of strontium hexaferrite in all samples, while the crystal structure of PVA is degraded due to the mechanical energy supplied from the milling process. However, the Infrared study (FTIR) indicated that the polymeric chain kept intact. Magnetic behavior, from vibrating sample magnetometry tests, shown a waist wasp type hysteresis loop, for all the composites SrFe 12 O 19 @PVA, confirming that both materials do not generate bonds, and there is only a mixture of materials. Finally, Rietveld refinement, SEM analysis, and particle size measurement allowed demonstrating that PVA reduces the crystallite and particle sizes at nanometers scale of strontium hexaferrite synthesized. Highlights • SrFe 12 O 19 @PVA with different ratio were obtained by high energy ball milling using sapphire balls during 3 h. • The effect of mechanical mill in the PVA material is reported. • A magnetic model of SrFe 12 O 19 @PVA wasp waist is proposed. • Nanoparticles of strontium hexaferrite were obtained and liberated in water using PVA as encapsulator. • The best ratio is 25% of PVA and 75% of strontium hexaferrite. [ABSTRACT FROM AUTHOR]

Graphical abstract The solventless conversion of ZnO into CoZn-ZIF could be promoted by adding cobalt acetate as both Co source and catalyst. Physicochemically distinct CoZn-ZIFs could be obtained by introducing Co and Zn elements into the frameworks while keeping the overall framework intact, resulting in the enhancement of CO 2 uptake. Abstract An efficient and simple methodology was proposed to synthesize bimetallic Co–Zn based zeolitic imidazolate frameworks (CoZn-ZIFs; Co x Zn (1− x) (2-methylimidazole) 2) with sodalite topology. The synthesis strategy is based on a solventless mechanochemical reaction using only powder raw material, zinc oxide, cobalt acetate, and 2-methylimidazole, for ease of handling and large-scale production. The solventless conversion of ZnO into CoZn-ZIF could be promoted by adding cobalt acetate as both Co source and catalyst. A feature of the acetate-assisted mechanosynthesis is that CoZn-ZIF particles are tens of micrometers in size and hierarchically structured. Co and Zn elements are homogeneously dispersed in the framework. Tuning the additive amount of cobalt acetate could vary the Co/Zn ratio of CoZn-ZIF particles. Compared with Zn-ZIF prepared by adding zinc acetate, CoZn-ZIFs exhibited enhanced CO 2 uptake. The enhancement of 35% for CO 2 uptake capacity at 298 K and 100 kPa was displayed by Co 0.9 Zn 0.1 -ZIF as compared to Zn-ZIF. [ABSTRACT FROM AUTHOR]

Ball-milling technique as a solvent-free and an alternative green process was investigated for the eco-benign synthesis of bis(indolyl)-methanes (BIMs) from various aldehydes and selected ketones with indoles in high yields. The present methodology has several advantages such as simple procedure, good yields, mild conditions, and reduced environmental consequences. The silica gel acts both as a grinding medium and an acid catalyst. The utility of this technique was demonstrated by synthesizing library of 17 BIMs including two natural products trisindoline and tris(1H-indol-3-yl)methane. [ABSTRACT FROM AUTHOR]

Abstract Niobium carbonitride [Nb(C,N)] nanoparticles were synthesized by a combustive mechanochemical reaction in the Mg/Nb 2 O 5 /C 3 H 6 N 6 system. High-energy ball milling was used to promote a mechanically induced self-sustaining reaction (MSR). Combustion occurred after a very short milling period of 5 min. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS) analyses revealed that the nature of the product is an intermixed carbonitride material. The formation mechanism of Nb(C,N) resulted from the magnesiothermic reduction of niobium oxide to generate elemental Nb, which then reacted with the species generated from the melamine decomposition. Graphical abstract Elemental mappings showing the distribution of niobium, carbon, and nitrogen. fx1 [ABSTRACT FROM AUTHOR]

• Four binary cocrystals have been synthesized utilizing liquid assisted grinding (LAG) method. • Conformationally flexible sulfur-containing bipyridines have been employed as molecular linkers with robust tripodal molecules as coformers to generate diverse network topologies. • SCXRD, PXRD, and thermal analyses were used to characterize all of the synthesized cocrystals. • The intermolecular interactions in each cocrystal were examined using a Hirshfeld surface analysis. Four binary cocrystals of cyanuric acid (CUA) and 5-aminoisophthalic acid (5AIPA) in combination with spacer aldrithiol-4 (ALDTHL) and 4,4′-dipyridyl sulfide (DPS) were prepared via Liquid Assisted grinding (LAG) method. Single crystal X-ray diffraction and powder X-ray diffraction techniques were used to elucidate their structures, which are further characterized using thermogravimetric analysis. While CUA produces 0.5:0.5 and 2:2 cocrystals with ALDTHL and DPS respectively; 5AIPA acid forms 1:1 cocrystals with both ALDTHL and DPS. Again, all the cocrystals adopt a sheet-like structure, with the exception of the (DPS) 2 •(CUA) 2 cocrystal, which displays an interpenetrated polycatenane type of molecular packing. In order to analyze the intermolecular interactions in the four cocrystals, Hirshfeld surface analysis was performed. [Display omitted] [ABSTRACT FROM AUTHOR]

Vanadium carbonitride (VCN) nanoparticles were synthesized by a mechanically induced magnesiothermic combustion in a Mg/V 2 O 5 /C 3 H 6 N 6 system. Initial materials ignited after a short milling time of 6 min. Various characterizations such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM) and elemental mapping confirmed that the product of the combustion was a mixed carbonitride. In this process, magnesium reduces vanadium oxide to generate elemental V and a great amount of heat. Melamine decomposes due to the temperature rise, and its decomposed species form the carbonitride compound. The chemical composition of the synthesized product was estimated to be VC 0.26 N 0.36 . [ABSTRACT FROM AUTHOR]

The influence of the nature of the process control agent (PCA) used in the mechanosynthesis of the magnetite nanoparticles has been studied. The two-step route used here for obtaining nanocrystalline/nanoparticles Fe 3 O 4 consists of a heat treatment, to prepare well-crystallised magnetite, followed by the mechanosynthesis process. Dry milled magnetite samples have been obtained as a reference, using the same conditions (duration and energy), to determine the influence of the process control agents (PCA). Three different PCAs have been used: benzene, ethanol and oleic acid. The characterisation of the magnetite particles has been performed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), magnetic measurements M(H), differential scanning calorimetry (DSC) and thermogravimetric (TG) measurements and Scanning Electron Microscopy (SEM). XRD and SEM analysis revealed a different processing mechanism for the two milling modes, wet and dry. In the case of dry milling, even for short milling times, iron contamination and formation of a wüstite – FeO phase is noticed. The use of the PCA during the milling process limits the above-mentioned contamination. Ethanol and benzene uses as PCA lead to synthesis of fine uniform sized particles. SEM images reveal the presence on nanoparticles. In the case of oleic acid, DSC, TG and magnetic measurements revealed the presence of a thin layer of oleic acid adsorbed on the particles. FTIR analysis highlighted the presence of both free and bonded oleic acid. The magnetisation of the samples was found to be linked to the powder contamination (FeO or oleic acid), structural defects or finite size effects. [ABSTRACT FROM AUTHOR]

Abstract: In this study, rhenium diboride (ReB2) was obtained by mechanosynthesis at 640 minutes of milling. The obtained ReB2 was stored at oxygen and moisture ambient environmental conditions to know the chemical stability. The results indicate that ReB2 is totally decomposed at oxygen and moisture ambient environmental conditions. Furthermore, the X‐ray diffraction (XRD) analysis of ReB2 samples after 26 months of storage shows that the final products of degradation are HReO4 (liquid), H3BO3, HBO2, and ReO3. Finally, a schematic diagram of the degradation sequence of ReB2 at oxygen and moisture ambient environmental conditions is proposed and validated with a thermodynamic analysis. [ABSTRACT FROM AUTHOR]

In this study, nanocomposites of monoferrite-activated carbon (Ferrite-AC) have been prepared by mechanosynthesis technique. Nanocomposites can be utilized as adsorbent for desulfurization of hydrocarbon liquid fuels. Nanocomposites were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDS) analysis, Fourier transform infrared (FTIR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmet-Teller (BET) and vibration sample magnetometer (VSM). Results showed that NiFe 2 O 4 -AC had better performance between other adsorbents. Adsorption rate of dodecanethiol was improved by increasing NiFe 2 O 4 -AC concentration. XPS results showed that the dodecanethiol was oxidized by the catalyst surface. BET surface erea of NiFe 2 O 4 -AC nanocomposite was 626 m 2 /g with porous structure. [ABSTRACT FROM AUTHOR]

Abstract: Ball milling techniques have been applied in the development of a mechanosynthesis of [Cp*Co(CO)I2], which proved highly efficient as catalyst in mechanochemical C−H bond amidations of indoles in a mixer ball mill. A wide range of amidated products is obtained in excellent yields. Compared to the solution‐based methods, the procedure opens a more feasible and environmentally‐friendly access to both the cobalt(III) catalyst and 2‐amidated indoles. [ABSTRACT FROM AUTHOR]

In this work, synthesis of NiAl–Al 2 O 3 nanocomposite powders via the mechanosynthesis route and by using Ni, NiO and Al is investigated. Ignition of the reaction inside the ball-mill vial happens after 110 min; NiO is totally finished and NiAl and Al 2 O 3 as product phases are formed. After 10 h of ball milling, raw materials are totally used in the reaction and only product phases exist in the vial. By continuing the ball milling process to 60 h, better mixing of the synthesized phases and decrement in their crystallite sizes plus particle size are observed. Crystallite sizes of the product phases are in the nanometer range in all ball milling times. Crystallite sizes of NiAl and Al 2 O 3 after 10 h are around 11 nm and 19 nm respectively, and these are reduced to around 8 nm for both phases after 60 h of ball milling. [ABSTRACT FROM AUTHOR]

By following a one-step, novel methodology, ZnO and Ag/ZnO heterostructures were successfully synthesized at room-temperature. This route is simple, effective, high yield (91%), environmentally friendly (green synthesis) and consists of a mechanically assisted metathesis reaction. The metathesis reaction used in this investigation showed two results: the in-situ generation of alkaline nitrates, LiNO 3 /NaNO 3 , and the direct crystallization of the desired Zn-based compounds in milling media; revealing a true mechanochemical synthesis of ZnO and Ag/ZnO (1.25, 2.50 and 4.50 mol% of Ag) heterostructures. Particles showed spherical-like morphologies and sizes smaller than 20 nm. The Ag/ZnO heterostructures exhibited higher photocatalytic activity than ZnO for degrading methylene blue (MB) dye. It was also shown that the presence of Ag (up to 1.25 mol%) nanoparticles (NPs) in ZnO accelerates the photodegradation reaction and then slows down with further increases in Ag contents. The 1.25-Ag/ZnO sample (10 mg) showed the highest photocatalytic activity (96%) for degrading MB (100 ml, 10 mg L −1 ) within 100 min under UV–Vis light irradiation (λ = 310 nm). [ABSTRACT FROM AUTHOR]