Recrystallization Method Research Articles

Komparasi Kebijakan Pengelolaan Limbah Medis Covid-19 Di Indonesia Dan Malaysia


 
 
 
 Masih banyak negara berkembang yang belum mengelola limbah medis Covid-19 secara tepat dan efektif padahal jumlah produksi limbah medis Covid-19 saat ini sangat mengkhawatirkan. Oleh karenanya penulis menganalisis serta mengkomparasi kebijakan-kebijakan yang diformulasikan dan diimplementasikan di Indonesia dan Malaysia. Kebijakan dan implementasi yang berbeda di Malaysia dijadikan sebagai rekomendasi penelitian disamping rekomendasi lainnya. Metode penelitian ini adalah deskriptif komparatif melalui pendekatan kualitatif dengan menggunakan data sekunder. Dari hasil studi literatur diperoleh hasil bahwa kebijakan pengelolaan limbah medis Covid-19 di Indonesia dan Malaysia tidak jauh berbeda. Masing-masing negara memiliki sebuah kebijakan strategis yang diformulasikan sebelum pandemi Covid-19 terjadi yaitu PP No.101 Tahun 2014 di Indonesia dan UU Mutu Lingkungan 1974 di Malaysia. Kebijakan tersebut oleh masing-masing negara dijabarkan ke dalam kebijakan-kebijakan operasional mengenai pengelolaan limbah medis Covid-19. Dalam implementasi dan monitoring, Indonesia dan Malaysia memiliki kesamaan sekaligus perbedaan. Kesamaannya adalah pemerintah berkolaborasi dengan beberapa intansi dan pihak swasta dalam pengelolaan limbah medis Covid-19, pemerintah melakukan sosialisasi kebijakan pengelolaan limbah medis Covid-19, inspeksi, menyediakan layanan pengaduan. Sementara perbedaannya adalah pemerintah Indonesia melakukan coaching clinic, menyiapkan fungsional penyuluh lingkungan, memperbolehkan pihak swasta yang masih dalam proses perizininan tetap dapat beroperasi sedangkan di Malaysia pengelolaan limbah medis Covid-19 dilakukan oleh tujuh perusahaan yang memiliki izin, menggunakan robot membantu pengelolaan limbah medis Covid-19, menerapkan sanksi denda dan kurungan penjara bagi pelanggar, menyediakan aplikasi Electronic Scheduled Waste Management. Strategi yang dilakukan oleh pemerintah Malaysia dapat dijadikan sebagai rekomendasi dalam pelaksanaan pengelolaan limbah medis Covid-19, disamping melakukan edukasi kepada masyarakat sampai tingkat RT dan RW dengan melibatkan perangkat desa, tokoh-tokoh agama, karang taruna, serta melakukan metode rekristalisasi, dan kendaraan pengangkut limbah medis Covid-19 dilengkapi sistem GPS dan barcode. 
 
 
 

Continuous‐Flow Synthesis of Orange Emitting Sn(II)‐Doped CsBr Materials

AbstractAn ongoing demand toward lead‐free all‐inorganic cesium metal halide perovskites has presented Sn(II) as an ideal substitute of Pb(II) for applications in optoelectronic devices. The major concern regarding Sn(II) is the instability due to the ambient oxidation to Sn(IV). To expand the scope of traditional perovskite and analogues, herein the synthesis and optical performance of Sn(II)‐doped CsBr, a new material formed by interstitial doping of Sn(II) into the CsBr matrix, are reported for the first time. This material is prepared following an antisolvent mediated recrystallization method using a continuous flow reactor, which is beneficial for scaling up the production compared to traditional batch reactors. Sn(II)‐doped CsBr exhibits broadband orange emission with full‐width‐half‐maximum of 180 nm and a photoluminescence quantum yield of 21.5%. The emission turned to be highly stable over 7 months despite containing Sn(II). It is suggested that this is due to interstitial location of Sn(II) atoms in bulk of microcrystals. A broadband emission and high aerobic stability are attractive properties of the material for white‐light emitting applications.

The New Biologically Active Metabolites from Aspergillus niveus 2411

Pharmacological science possesses a significant number of compounds with antibiotic activity. By now the chemical structures have been identified and their properties have been described for the great number; many of them found practical use. But the main stimulus for the further new antibiotic compounds search is the acquired resistance of pathogenic organisms. Our previous investigations were devoted to antibiotic activity of Aspergillus niveus that is known as a producer of ferment preparations with wide activity spectrum. Aim. This investigation became the follow-up of our previous studies and its main task was to isolate, purify and obtain biologically active metabolite(s) from A. niveus 2411 strain in crystalline form, and to study its (their) physicochemical properties and biological activity. Methods. Biologically active metabolites were obtained by extraction, two-step column chromatography and recrystallization methods. The obtained substances were characterized by physical-chemical and microbiological methods. Results. Two substances in crystalline form with different spectrum of antibiotic activity against indicator test-cultures were obtained. The substance AN4 showed antibacterial, antifungal, and phytotoxic activities, while AN7 showed only antibacterial activity. Neither of obtained compounds showed dermatocidal or toxigenic activity in rabbit skin test. Obtained spectral characteristics of substances suggest that AN4 and AN7 substances are similar and belong to compounds with cyclic structures, have double linkage, methyl, aromatic, and carboxyl groups. Conclusions. Obtained data showed that antibiotic activity of A. niveus 2411 depend on the complex of biologically active metabolites with different biological and physicochemical properties. Two compounds AN4 and AN7 were isolated and purified from the fungal cultural filtrate of A. niveus 2411. The data of IR and UV spectra of these compounds and their profiles of biological activity don’t have significant differences with those of citrinin – a metabolite of A. niveus with antibiotic properties. However, based on the results obtained and comparisons with the data of other authors on metabolites of A. niveus, we suggest that the substances we isolated may be derivatives of citrinin.

Preparation and growth mechanism of micro spherical ammonium dinitramide crystal based on ultrasound-assisted solvent-antisolvent method

Micro-sized spherical ammonium dinitramide (ADN) crystals are successfully prepared by a facile ultrasound-assisted solvent-antisolvent recrystallization method without introducing any additives. The influences of the volume ratio of solvent to antisolvent, the antisolvent temperature and the ultrasound power on the micro-morphologies and properties of ADN crystals are studied systematically. The changes of morphology, particle size, crystal structure and melting point of the ADN crystals are characterized through scanning electron microscopy (SEM), laser particle size analyzer (LPSA), X-ray diffraction (XRD) and differential scanning calorimetry (DSC), respectively. The results show that the optimal experimental parameters for the ADN crystal of spherical morphology are as follows: the volume ratio of solvent to antisolvent is 1:50, the antisolvent temperature is 20 ℃, and the ultrasound power is 70 W. The predicted hexagonal-flake and spherical morphologies for the ADN are close to the experimental morphologies. The growth mechanism of the spherical ADN crystal changes with supersaturation of the ADN solution. As the degree of supersaturation increases, the growth models of the spherical ADN change from the spiral growth to the rough growth, and the morphologies of ADN change from the large-sized ADN ball to the small-sized ADN ball.

Effects of Trace Amounts of Mn, Zr and Sc on the Recrystallization and Corrosion Resistance of Al-5Mg Alloys

This study aimed to explore the effects of trace amounts of Mn, Zr, and Sc on the recrystallization behavior and corrosion resistance of Al-5Mg alloys after process annealing by means of alloy design and microstructure analysis of electron backscatter diffraction (EBSD), electron microprobe (EPMA), and electron microscopes (TEM and SEM). The main objective was to obtain alloys with better corrosion resistance. The results show that the fine Al3Zr and Al3Sc precipitated particles were both superior to the MnAl6 particles in inhibiting grain and sub-grain boundary migrations. Therefore, the Zr-containing and Sc-containing alloys were better than the Mn-containing alloy in inhibiting recrystallization. For further comparison, the thermal stability of the Al3Sc particles was better than that of the Al3Zr particles, so the Sc-containing alloy at the high temperature above 350 °C inhibited grain growth better than the Zr-containing alloy. During the recovery stage of the alloy in the recrystallization process, the β-Mg2Al3 phase precipitated on the sub-grain boundary, thus reducing the occurrence of intergranular corrosion. However, in the initial stage of recrystallization, the β-Mg2Al3 phase continuously precipitated on the grain boundary, causing obvious intergranular corrosion. For the Sc-containing alloy, because there was no obvious grain growth stage, the β-Mg2Al3 phase continuously precipitated on the grain boundary, and thereby intergranular corrosion occurred. Therefore, its corrosion resistance was greatly reduced. By contrast, for the alloy containing Mn or Zr, because of obvious grain growth, magnesium atoms aggregated. As a result, the β-Mg2Al3 phase discontinuously precipitated on the grain boundary. The corrosion morphology was local pitting corrosion rather than intergranular corrosion, and thus the corrosion resistance of the alloy was enhanced. As a novelty, this study clearly observed the sensitized precipitation and corrosion morphology of the β-Mg2Al3 phase of Al-5Mg alloy under different recrystallization methods. This will be of benefit to the design of anti-corrosion measures for the future manufacturing and application of Al-5Mg alloy.

Volatile Profiling Aided in the Isolation of Anti-Proliferative Lupeol from the Roots of Clinacanthus nutans (Burm. f.) Lindau

Isolation of anti-proliferative compounds from plants is always hindered by the complexities of the plant’s nature and tedious processes. Clinacanthus nutans (Burm. f.) Lindau is a medicinal plant with reported anti-proliferative activities. Our study aimed to isolate potential anti-proliferative compounds present in C. nutans plant. To start with, for our study, we came up with a strategy by first profiling the volatile compounds present in the leaf, stem and root of C. nutans using GC-MS. Comparing the plant’s volatile profiles greatly narrowed down our target of study. We decided to start with the isolation and characterization of a pentacyclic terpenoid, i.e., lupeol from the roots of C. nutans, as this compound was found to present abundantly in the roots compared to the leaf or stem. We developed a simple maceration and re-crystallization method, without the necessity to go through the fractionation or column chromatography for the isolation of lupeol. Characterizations of the isolated compound identified the compound as lupeol. The anti-proliferative activity of the isolated lupeol was further investigated against the MCF-7 cell line, which showed comparable anti-proliferative activity with the authentic lupeol and camptothecin. Our strategy to profile every part of the plant first, followed by selection of the most suitable plant part and targeted compound proved useful for further isolation and characterization bioactive compound from C. nutans.

Tensoresistive properties of single crystals TlIn1−xGaxSe2

In this work, single crystals of TlIn[Formula: see text]Ga[Formula: see text]Se2 solid solutions were grown by the methods of zone recrystallization, technologies for the manufacture of strain gauges based on them were developed and the tensoresistive properties of these phases were studied, the coefficient of strain sensitivity was determined by the static method depending on the temperature, the magnitude of mechanical deformation and optical illumination. Revealing that the single crystals have a high strain sensitivity coefficient, by the variation of the composition, quantity of mechanical deformation and the optical illumination, it is possible to control the phase coefficients investigated tensosensitivity.

Highly efficient azido-Ugi multicomponent reactions for the synthesis of bioactive tetrazoles bearing sulfonamide scaffolds

Recent studies revealed that the contribution of the different bioactive scaffolds in one structure creates modern drugs/compounds with unique synergistic biological properties. In this regard, thanks to the interesting biological and medicinal properties of sulfonamide and tetrazole skeletons, this study describes the engagement of sulfonamides in the Ugi tetrazole reaction to access a library of tetrazole bearing sulfonamide. This four-component reaction was performed in a one-pot among available starting material, i.e., an isocyanide, a sulfonamide, an aldehyde and sodium azide in MeOH at 45 °C using ZnCl 2 as a catalyst, for the synthesis of very versatile products with high atom economy and yields. The key point in this strategy is the formation of an intermediate Schiff base and its activation in the azido-Ugi reaction by a Lewis acid catalyst. Importantly, all products are purified through the group-assisted purification (GAP) chemistry, which can avoid traditional purification such as recrystallization and chromatography methods. Also, the docking study between the synthesized compounds and human serum albumin (HSA) was stimulated to theoretically rationalize their biological activity and potential binding interactions.

All-Inorganic Perovskite Nanorod Arrays with Spatially Randomly Distributed Lasing Modes for All-Photonic Cryptographic Primitives.

The level of hardware or information security can be increased by applying physical unclonable functions (PUFs), which have a high complexity and unique nonreplicability and are based on random physical patterns generated by nature, to anticounterfeiting and encryption technologies. The preparation of PUFs should be as simple and convenient as possible, while maintaining the high complexity and stability of PUFs to ensure high reliability in use. In this study, an all-inorganic perovskite single-crystal array with a controllable morphology and a random size was prepared by a one-step recrystallization method in a solvent atmosphere to generate all-photonic cryptographic primitives. The nondeterministic size of the perovskite nanorods mainly arises from crystal growth in an indeterminate direction, producing a high entropy for the system. The cavity-size-dependent lasing emission behavior of perovskite single crystals was investigated as a preliminary exploration of the generation of all-photonic cryptographic primitives. The lasing-mode number was positively correlated with the length of the perovskite nanorods. Therefore, the prepared perovskite nanorod array with random sizes can be transformed into a quaternary cryptographic key array following encoding rules based on the lasing-mode number. Superior lasing stability was observed for the all-inorganic perovskite under continuous excitation, demonstrating the high reliability of this system.

Synthesis of porous iron hydroxy phosphate from phosphate residue and its application as a Fenton-like catalyst for dye degradation

Phosphate residue is a kind of hazardous solid waste and if not properly disposed of, could cause serious environmental contaminations. The abundant iron salt available in phosphate residue can be used to prepare photo-Fenton catalytic reagent for wastewater treatment. In this study, the phosphate residue was effectively purified by a hydrothermal recrystallization method, reaching an iron phosphate purity of 94.2%. The particles of iron phosphate were further processed with ball milling with their average size reduced from 19.4 to 1.6 μm. By hydrothermal crystallization of iron phosphate and thermal decomposition of oxalate precursor, porous iron hydroxy phosphate was prepared. The modified porous iron hydroxy phosphate (m-PIHP) of higher surface area with iron oxalate on its surface can degrade 98.87% of Rhodamine B in 15 min. Cyclic experiment showed that the catalyst still had a good catalytic activity after six cycles (>40%). The X-ray photoelectron spectroscopy results showed that the iron oxalate complex on the catalyst surface decomposed to produce ferrous ions and accelerated the rate of •OH production. The current work demonstrated that the m-PIHP synthesized from phosphate residue and modified with iron oxalate can be used as an effective dye wastewater treatment agent.

Synthesis of Highly Active Nanozeolites Using Methods of Mechanical Milling, Recrystallization, and Dealumination (A Review)

Synthesis of Highly Active Nanozeolites Using Methods of Mechanical Milling, Recrystallization, and Dealumination (A Review)

Role of the heat treatment of partial melt recrystallization method on microstructure change and toughness of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(HB-co-HV)

The microstructure of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(HB-co-HV)] was regulated by the heat treatment of partial melt recrystallization method (PMRM) to improve its mechanical properties effectively. The structural changes and toughening mechanism of P(HB-co-HV) were investigated by polarized optical microscopy (POM), differential scanning calorimetry (DSC), and wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), scanning electron microscope (SEM) as well as dynamic mechanical analysis (DMA) experiments. The imperfect crystals of P(HB-co-HV) melted at 176 °C while the remaining perfect crystals recrystallized at the higher temperature (Tc = 120–150 °C). The results demonstrated that the HV units were easily to be excluded from the PHB crystal lattice in the P (HB-co-HV) recrystallization process, which promoted the crystal perfection of P(HB-co-HV) and improved the tensile strength and melting temperature. Furthermore, the heat treatment of PMRM reduced the molecular chain density and entanglement in the amorphous region and made the distribution of the tensile degree of the molecular chains more uniform, which was conducive to the sliding of lamellar crystals along the impact tensile direction, inducing plastic deformation. In addition, the heat treatment of P(HB-co-HV) via PMRM produced a large number of micropores, which was conducive to dispersing stress and improving its macroscopic toughness during the subsequent stretching process.

Systemic Review of Screening the Shapes of Ibuprofen Particles in Different Solvents

Ibuprofen is a very popular analgesic which is mostly available in the market as tablet dosage form. The ibuprofen molecule possesses a chiral center in the propionic acid group. So, there are two enantiomers (R and S), whose chemical properties are similar, but which have optical rotations of opposite sign. The (-) form (l- or laevo-) is the R (-) enantiomer whereas the (+) form (d or dextro-) is referred to as S (+) – ibuprofen. The R (-) isomer is biologically inactive while the S (+) isomer is active. The R (-) form however is slowly converted to the S (+) active form during metabolism in the human body by the presence of the enzyme isomerase (2-arylpropionyl-CoA epimerase). Thus, a large difference in the body potency between the two enantiomers is not found.
 During manufacturing of tablet, ibuprofen particle plays a significant role in flowability and compressibility etc. Theoretically particle size and shape have great impact on those sorts of mechanical properties of tablets. The morphology can influence physical properties such as packing density, bulk density, agglomeration, and dissolution behaviour as well as the mechanical strength and wet ability. Furthermore, crystal shapes have also been found to have an effect on the bioavailability of the resulting APIs. Commercial ibuprofen typically has a needle shaped morphology with rough surfaces and show poor flowability, poor compaction behavior and a tendency to stick to the tablet punches. To overcome these problems, a suitable size and shape of ibuprofen crystal is desirable that could be directly compressed with fewer operation steps but still having good product stability and therapeutic efficacy, but it can be changed through recrystallization or other methods such as spray drying, etc. Ibuprofen crystallized from solvents with a high hydrogen bonding ability like methanol will form chunky crystals and low hydrogen bonding solvents like hexane will form needle like crystals. Therefore, it was necessary to review the shapes of ibuprofen particles in different solvents.
 This review paper has covered a comprehensive studies of ibuprofen particle shapes in different solvents and cosolvents.

One-step in situ formation of 3D hollow sphere-like V2O5 incorporated Ni3V2O8 hybrids with enhanced photocatalytic performance

3-D hollow sphere-like Ni3V2O8 immobilizing V2O5 nanoparticles were successfully synthesized via in situ recrystallization method without any template. The compact contact between V2O5 and Ni3V2O8 ensuring the photo-inducted carriers fast transport, which would be beneficial for inhibiting recombination rate of electron-hole (e-/h+) pairs. Moreover, the hollow sphere-like structure composed of the smaller nanoparticle could effectively improve of visible light capture capacity (multiple scattering for hollow architectures). Benefiting the synergistic promoting effect of the suitable heterojunction and the fascinating 3D hollow feature, the V2O5@Ni3V2O8 indicated significantly degradation performance when evaluated as photocatalyst for degradation antibiotics and chlorophenols under visible light irradiation. Impressively, the 2-V2O5@Ni3V2O8 heterojunction deliver the optimal degradation efficiency for TC (OTC) and 2,4-DCP (4-CP) were 90.0% (~91.2%) and 92.6% (~90.0%), respectively. The appearance mechanism for the enhancement photocatalytic performance was also elucidated in detail. The facile strategy provides a novel insight into the designing of the photocatalyst with advantages of charges separation and light-harvesting for degradation of contaminants in wastewater.

Ultrasonic microwave-assisted micellar extraction and purification of flavonoids from licorice by metal complex and antisolvent recrystallization

This study aims to extract and purify flavonoids from licorice by an efficient and environmentally friendly approach. The ultrasonic microwave-assisted micellar extraction (UMAME) method was used to extract licorice flavonoids (LFs). The optimal extraction parameters including lauryl sodium sulfate concentration, microwave power, solvent-material ratio and extraction time were investigated by a single factor method and response surface methodology. The extraction rate of LFs was up to 3.65% under the optimal conditions. The extraction solution was pretreated with ethyl acetate and the purity of raw LFs reached 36.47%. The purity of raw LFs was increased from 36.47% to 90.32% by metal complex method and antisolvent recrystallization method. The antioxidant test results showed that the finally purified LFs with an IC50 value of 3.519 μg/mL had a strong scavenging ability on DPPH free radical.

Facile room temperature synthesis of ultra-small sized porous organic cages for fluorescent sensing of copper ion in aqueous solution

Facile synthesis of nano porous organic cages with small size and good fluorescence property is highly desirable, but still challenging and scarce for their sensing applications. Here we report a rapid room-temperature recrystallization method for the preparation of nano porous organic cages with ultra-small size as a fluorescent probe for copper ion. The prepared nano porous organic cages gave the diameter of 2.49 ± 0.04 nm, and exhibited stable emission at 535 nm with absolute quantum yield of 0.68%. On the basis of the coordination interaction and charge transfer between the nano porous organic cages and copper ion, a simple fluorescent probe for copper ion in aqueous solution was developed. The developed method gave a calibration function of QE = 0.4815lg[Cu2+] + 0.5847 (where QE is the quenching efficiency; [Cu2+] in μM) (R2 = 0.9987) in a concentration range of 0.1–2 μM, the limit of detection (3s) of 8 nM, and the relative standard deviation of 0.36% for 10 replicate determinations of 0.5 μM copper ion. The recoveries of spiked copper ion in tap water samples ranged from 96.8% to 103.0%. The proposed method possesses good sensitivity, selectivity and accuracy.

FLAVONOIDS OF THE EAST ASIAN SPECIES SERRATULA MANSHURICA KITAG.

One of the poorly studied and widespread plants in the Russian Far East is the Manchurian saw-wort (Serratula manshurica Kitag.). It is known that this plant is rich in phytoecdysteroids, which have high biological activity (anabolic, adaptogenic, cardiotropic, immunomodulatory effects). Two biologically active compounds of the flavonoid class were isolated from the aerial part of Serratula manshurica Kitag. Growing in the Primorsky Kray of the Far East of Russia by liquid extraction and recrystallization methods: quercetin-4'-O-β-D-glucuronopyranoside and apigenin-7-O-β-D-glucuronopyranoside. The structure of the isolated compounds was proved by UV-, NMR-spectroscopy and mass spectrometry with electrospray ionization. The quantitative content of flavonoids in the aerial part of the Serratula manshurica plant in different phenological phases of plant development (luteolin-4'-O-β-D-glucuronopyranoside, quercetin-4'-O-β-D-glucuronopyranoside, apigenin-7-O-β-D-glucuronopyranoside, 3-methylquercetin-4'-O-β-D-glucuronopyranoside, quercetin, apigenin, 3-methylquercetin, luteolin, isokaempferide) was determined by the method of reversed phase liquid chromatography (RP HPLC). It was shown that the maximum content of flavonoid aglycones in plants was observed during the beginning of the growing season and in the budding phase, and their glycosides - during the flowering phase. Thus, to obtain plant material with the maximum content of flavonoid aglycones (quercetin, 3-methylquercetin, luteolin) the collection of vegetative mass should be carried out during the beginning of the growing season, and their glycosides - during the flowering period. Serratula manshurica Kitag., which grows abundantly on the territory of Primorsky Krai, can be considered a constantly renewable and promising source for obtaining flavonoids.

Impact of Formulation Parameters on In Vitro Release from Long-Acting Injectable Suspensions.

The development of long-acting injectable (LAI) suspension products has increased in recent years. A better understanding of the relationship between the physicochemical properties of these products and their in vitro as well as in vivo performance is expected to further facilitate their development and regulatory review. Using Depo-SubQ Provera 104® as the reference listed drug (RLD), four qualitatively and quantitatively (Q1/Q2) equivalent LAI suspensions with different formulation properties were prepared. Two recrystallization methods (solvent evaporation and antisolvent) were utilized to obtain active pharmaceutical ingredient (API) with different properties and solid-state characterization was performed. In addition, two different sources of the major excipient were used to prepare the Q1/Q2 equivalent suspensions. Physiochemical characterization and in vitro release testing of the prepared Q1/Q2 equivalent suspension formulations and the RLD were conducted. In vitro drug release was dependent not only on the particle size, the morphology, and the crystallinity of the API but also on the residual solvent in the API. The excipient source also affected the drug release rates.

Flake (NH4)6Mo7O24/ Polydopamine as a High Performance Anode for Lithium Ion Batteries.

Ammonium molybdate tetrahydrate ((NH4)6Mo7O24) (AMT) is commonly used as the precursor to synthesize Mo-based oxides or sulfides for lithium ion batteries (LIBs). However, the electrochemical lithium storage ability of AMT itself is unclear so far. In the present work, AMT is directly examined as a promising anode material for Li-ion batteries with good capacity and cycling stability. To further improve the electrochemical performance of AMT, AMT/polydopamine (PDA) composite was simply synthesized via recrystallization and freeze drying methods. Unlike with block shape for AMT, the as-prepared AMT/PDA composite shows flake morphology. The initial discharge capacity of AMT/PDA is reached up to 1471 mAh g−1. It delivers a reversible discharge capacity of 702 mAh g−1 at a current density of 300 mA g−1, and a stable reversible capacity of 383.6 mA h g−1 is retained at a current density of 0.5 A g−1 after 400 cycles. Moreover, the lithium storage mechanism is fully investigated. The results of this work could potentially expand the application of AMT and Mo-based anode for LIBs.

Promoted production of hydrocarbons in the catalytic pyrolysis of rape straw over composite HZSM-5@MCM-41 catalysts

In order to promote the production of hydrocarbons in the catalytic pyrolysis of rape straw, a core-shell catalyst fabricated by external recrystallization method was employed. The composite catalyst HZSM-5@MCM-41 was prepared by varying the mass ratio of template and HZSM-5 (THR), and the effect of zeolite acidity and mesoporosity on the production of hydrocarbons was analyzed. A final pyrolysis temperature of 500 °C was suitable to obtain high yield of hydrocarbons over composite catalysts. Compared with ZSM-5 with a favorable pyrolysis temperature of 550 °C, a lower pyrolysis temperature meant a more efficient process, which may be related closely to the good diffusion of large-sized pyrolysis vapors over HZSM-5@MCM-41 catalysts. In addition, the highest yield of monocyclic aromatic hydrocarbons obtained over HZSM-5@MCM-41 with THR of 1 was 11.43 wt.%, which was boosted by 2.5 times compared with HZSM-5. A proper THR was suitable to fabricate a core-shell catalyst with excellent crystallinity, acidity and mesoporosity, and resulting in a high yield of hydrocarbons. Furthermore, the core-shell catalyst presents less formation of graphite-like coke, which indicated the easier removal of coke. Therefore, the composite HZSM-5@MCM-41 catalysts were more appropriate for upgrading of pyrolysis vapors for hydrocarbons.