Facile Scalable Synthesis Research Articles

Introducing N-Heterocyclic Iminophosphoranes (NHIPs): Synthesis by [3 + 2] Cycloaddition of Azophosphines with Alkynes and Reactivity Studies

Azophosphines (Ar-N═N-PR2) were prepared from N-aryl-N'-(trimethylsilyl)diazenes (Ar-N═N-SiMe3) and R2PCl by Me3SiCl elimination or oxidation of phosphinohydrazines (Ar-NH-NH-PR2) by 2,5-dialkyl-1,4-benzoquinones. Azophosphines underwent 1,3-dipolar cycloaddition with cyclooctyne and dimethylacetylene dicarboxylate to give N-heterocyclic iminophosphoranes (NHIPs), which are structurally similar to cyclic (alkyl)(amino)carbenes. The cycloaddition reaction is compatible with various phosphorus atom substituents including phenyl (NHIP-1,4,6), isopropyl (NHIP-2), cyclohexyl (NHIP-3), and dimethylamino (NHIP-5) groups. The pKBH+ values of the NHIPs in acetonitrile range from 13.13 to 23.14. On the basis of the Huynh electronic parameter, NHIP-1 and NHIP-2 have σ-donor strengths comparable with that of 1,8-diazabicyclo[5.4.0]undec-7-ene. NHIP-1 underwent facile 1,2-addition with pentafluoropyridine to form a rare fluorophosphorane. The treatment of NHIP-1 with triphenylsilane resulted in P-N bond cleavage, accompanied by the reduction of phosphorus(V) to phosphorus(III). A homoleptic, cationic CuI-NHIP-1 complex was also prepared. The potential utility of π-donating NHIPs was demonstrated by the stabilization of a reactive iminoborane (Cl-B≡N-SiMe3). The facile scalable synthesis, tunability of steric demands, and basicity of NHIPs suggest that this new heterocycle class may find a wide range of applications in synthetic chemistry.

Simple and Scalable Ball Milling Synthesis of MoS2/Graphite Heterostructures with High Rate Capability for Li-Ion Batteries

With the constant rise of consumer demands for energy storage devices, improvements in current Li-ion battery (LIB) technology are paramount. At present, graphite is the most common commercial anode material, with a theoretical capacity of 372 mA h g-1. However, it is inevitable that graphite alone will no longer suffice to meet large capacity and high power requirements.Transition metal dichalcogenides (TMDs) are isostructural analogues of graphite where a transition metal layer is sandwiched between two chalcogen layers by strong intraplanar bonds while each unit is stacked together through weak van der Waal’s interplanar forces. MoS2 is a TMD which has also been considered as a potential candidate for LIB anodes as its theoretical capacity (670 mA h g-1) is almost double that of graphite. Unfortunately, the anode’s practical performance is very poor due to large volume expansion upon charging/discharging and formation of undesirable polysulphides.Combining MoS2 and graphite could generate an alternating layer heterostructure that exploits the desirable properties of each material. Most syntheses of MoS2/Graphite heterostructures in the literature either require extensive reaction conditions such as long periods of ultrasonication, or produce very low yields such as chemical vapour deposition. Additionally, ultrasonication often introduces many undesirable defects, due to the solvent used and harsh conditions. Alternatively, dry ball milling is a scalable and economically viable technique for producing MoS2/Graphite heterostructures. The process uses mechanical forces exerted by balls to strip layered materials through their weaker van der Waal’s bonding. To date, the only MoS2/Graphite composite synthesised with this method (though under Ar) for Li-ion batteries, was ball milled for 40 hrs and exhibited a practical capacity of ~700 mA h g-1 at 100 mA g-1 current density for 100 cycles.(1)This work uses simple dry ball milling under atmospheric conditions for 12 hrs to synthesise a MoS2/Graphite composite which exhibits ~350 mA h g-1 at a high current density of 1 A g-1. Additionally, this work shows that dry ball milling MoS2 alone for 12 hrs produces a phase transformation to a conductive 1T MoS2 product. Raman spectroscopy, XRD, XPS, SEM and impedance spectroscopy techniques were used to characterise the materials. By combining MoS2 and graphite with this simple and scalable method, we provide a viable solution to meet rising consumer demands of improved energy storage devices.(1) Zhao H, Zeng H, Wu Y, Zhang S, Li B, Huang Y. Facile scalable synthesis and superior lithium storage performance of ball-milled MoS2-graphite nanocomposites. J Mater Chem A. 2015;3(19):10466–70.

Facile scalable synthesis of graphene oxide and reduced graphene oxide: comparative investigation of different reduction methods

Facile scalable synthesis of graphene oxide and reduced graphene oxide: comparative investigation of different reduction methods

In-Situ Synergistic 2D/2D MXene/BCN Heterostructure for Superlative Energy Density Supercapacitor with Super-Long Life.

The 2D/2D layered materials are gaining much-needed attention owing to the unprecedented results in supercapacitors by their robust structural and electrochemical compatibility. Here, a facile scalable synthesis of 2D/2D MXene/boron carbon nitride (BCN) heterostructure through no residue direct pyrolysis is reported. The process allows the in-situ growth of BCN nanosheets unravelling the surfaces of MXene synergistically that provide an interconnected conductive network with wide potential window, augmented proportion of Ti sites at elevated temperature removing terminal groups enabling high pseudocapacitive activity and impressive stability. As a result, the as-assembled MXene/BCN electrode records a high specific capacitance of 1173 F g-1 (1876 C g-1 ) at 2 A g-1 and an energy density of 45Wh kg-1 . Further, the fabricated solid-state device exhibits an ultra-high cyclability of 100% capacitive retention after 100000 cycles. This will be an epitome for future 2D/2D heterostructures with commendable electrochemical properties as an expedient solution for energy storage applications.

Microsized SnS/Few‐Layer Graphene Composite with Interconnected Nanosized Building Blocks for Superior Volumetric Lithium and Sodium Storage

To develop anode materials with superior volumetric storage is crucial for practical application of lithium/sodium‐ion batteries. Here, we have developed a micro/nanostructured SnS/few‐layer graphene (SnS/FLG) composite by facile scalable plasma milling. Inside the hybrid, SnS nanoparticles are tightly supported by FLG, forming nanosized primary particles as building blocks and assembling to microsized secondary granules. With this unique micro/nanostructure, the SnS/FLG composite possesses a high tap density of 1.98 g cm−3 and thus ensures a high volumetric storage. The combination of SnS nanoparticles and FLG nanosheets can not only enhance the overall electrical conductivity and facilitate the ion diffusion greatly, but alleviate the large volume expansion of SnS effectively and maintain the electrode integrity during cycling. Thus, the densely compacted SnS/FLG composite exhibits superior volumetric lithium and sodium storage, including high volumetric capacities of 1926.5/1051.4 mAh cm−3 at 0.2 A g−1, and high retained capacities of 1754.3/760.3 mAh cm−3 after 500 cycles at 1.0 A g−1. With superior volumetric storage performance and facile scalable synthesis, the SnS/FLG composite can be a promising anode for practical batteries application.

Facile synthesis of 2D ultrathin and ultrahigh specific surface hierarchical porous carbon nanosheets for advanced energy storage

Two dimensional (2D) porous carbon nanosheets (CNS) have attracted tremendous research interests in energy storage and conversion, such as supercapacitors (SCs) and lithium-sulfur batteries, because of their unique micromorphology, chemical stability and high specific surface area (SSA). Rational design and facile scalable synthesis of CNS with high SSA, low cost and ultrathin nanosheet structure is highly desired but hitherto remains a big challenge. Here, we report a novel synthesis method of 2D hierarchical porous CNS with ultrahigh SSA (2687 m2 g−1) and ultrathin structure by directly pyrolysing and activating a unique and abundant biomass sheet. The electrochemical characterisations show that the prepared CNS-4-1 materials as electrodes creates a good energy-storage capability, with the energy density being 91 Wh kg−1 for symmetric SCs in ionic liquids, which is the highest in the reported biomass-derived CNS materials for SCs applications so far. Besides, the CNS-5-1 also exhibits a high initial capacity of 1078 mAh g−1 at 0.1 C when it acted as a sulfur hosting material for lithium-sulfur batteries. More importantly, it also shows a 586 mAh g−1 reversible capacity and an approaching 100% coulombic efficiency after 500 cycles at a high rate of 1 C. These superior electrochemical properties of the CNS are mainly attributed to their unique 2D ultrathin nanosheet structure, large SSA, and reasonable hierarchical porous structure. This work not only provides a new strategy to fabricate the ultrathin CNS in large scale and low cost but also enlarges CNS materials potential applications in energy storage.

Facile Scalable Synthesis of Carbon‐Coated Ge@C and GeX@C (X=S, Se) Anodes for High Performance Lithium‐Ion Batteries

AbstractAmorphous germanium@C and germanium chalcogenides@C composites have been fabricated via a simply developed synthetic route. Taking advantage of the carbon coating of these materials, they all exhibit excellent Li storage properties as anode materials for lithium ion batteries (LIBs). Typically, Ge@C presents a capacity of 672 mAh g−1 after 80 cycles at current density of 0.5 A g−1. The capacities of GeS@C are about 604 mAh g−1 over 180 cycles at 0.2 A g−1 and 365 mAh g−1 at 0.5 A g−1 after 1000 cycles, respectively. As for GeSe@C electrode, it exhibit high capacities of nearly 780 mAh g−1 at 0.2 A g−1 over 180 cycles and 562 mAh g−1 at 0.5 A g−1 over 60 cycles.

Scalable Synthesis of Hierarchical Antimony/Carbon Micro-/Nanohybrid Lithium/Sodium-Ion Battery Anodes Based on Dimethacrylate Monomer

A facile scalable synthesis of hierarchical Sb/C micro-/nanohybrid has been addressed in this work, which possesses the advantages of both micrometer and nanometer scale structures as lithium-ion battery anode. Difunctional methacrylate monomers are used as solvent and carbon source as well. Liquid precursor of antimony(III) n-butoxide is dissolved in the resin monomer solution, and further incorporated into the cross-linking polymer network via photo polymerization. Through calcination in argon/hydrogen atmosphere, antimony nanoparticles are in situ formed by carbothermal reduction, and homogeneously embedded in the in situ formed micrometer sized carbon matrix. The morphology, structure, crystallinity, spatial dispersion, composition, and electrochemical performance of the Sb/C micro-/nanohybrid are systematically investigated. The cyclic and rate performance of the Sb/C micro-/nanohybrid anode have been effectively improved compared to the pure carbon anode. A reversible capacity of 362 mAh g−1 is achieved with a reasonable mass loading density after 300 cycles at 66 mA g−1, corresponding to capacity retention of 79%. With reducing mass loading density, the reversible capacity reaches 793 mAh g−1 after 100 cycles. Moreover, the electrochemical performance of Sb/C micro-/nanohybrid as sodium-ion battery anode is also investigated in this study. Sb/C hierarchical micro-/nanohybrid lithium-ion battery anode with good cyclic stability is synthesized in a scalable way using difunctional methacrylate monomers as solvent and carbon source, where a reversible capacity of 362 mAh g−1 is achieved after 300 cycles with a reasonable mass loading density, corresponding to capacity retention of 79%

Scalable in Situ Synthesis of Li4Ti5O12/Carbon Nanohybrid with Supersmall Li4Ti5O12 Nanoparticles Homogeneously Embedded in Carbon Matrix.

Li4Ti5O12 (LTO) is regarded as a promising lithium-ion battery anode due to its stable cyclic performance and reliable operation safety. The moderate rate performance originated from the poor intrinsic electron and lithium-ion conductivities of the LTO has significantly limited its wide applications. A facile scalable synthesis of hierarchical Li4Ti5O12/C nanohybrids with supersmall LTO nanoparticles (ca. 17 nm in diameter) homogeneously embedded in the continuous submicrometer-sized carbon matrix is developed. Difunctional methacrylate monomers are used as solvent and carbon source to generate TiO2/C nanohybrid, which is in situ converted to LTO/C via a solid-state reaction procedure. The structure, morphology, crystallinity, composition, tap density, and electrochemical performance of the LTO/C nanohybrid are systematically investigated. Comparing to the control sample of the commercial LTO composited with carbon, the reversible specific capacity after 1000 cycles at 175 mA g-1 and rate performance at high current densities (875, 1750, and 3500 mA g-1) of the Li4Ti5O12/C nanohybrid have been significantly improved. The enhanced electrochemical performance is due to the unique structure feature, where the supersmall LTO nanoparticles are homogeneously embedded in the continuous carbon matrix. Good tap density is also achieved with the LTO/C nanohybrid due to its hierarchical micro-/nanohybrid structure, which is even higher than that of the commercial LTO powder.

Synthesis of chalcopyrite-type and thiospinel minerals/materials by low temperature melts of xanthates.

Xanthate complexes are used in the low temperature atom efficient synthesis of some geological and technologically important ternary compounds. The process involves direct heating of a stoichiometric mixture of the metal xanthate complexes. The reactive melts of the xanthates, generated in the transition state, cleanly decompose to ternary metal sulfides. The method has great potential for the facile scalable synthesis of ternary materials of composition ABX2 (such as AI = Ag, Cu; BIII = Bi, Cr, Fe, In, Sb and X = S) or AB2X4 (AII = Cd, Co, Cu, Ni; BIII = Co, Cr, Ni, Fe, and X = S).

Facile scalable synthesis of ordered macroporous few-layer MoS2 and carbon hybrid nanoarchitectures with sodium-ion batteries

Heterogeneous interfaces interaction and multiscale nanostructures in two-dimensional (2D) materials hybrids are critically significant for realizing rate capability and long-life cycling performance. However, to strike a balance between minimizing the carbon content and maximizing the heterogeneous interfaces remains a critical challenge in nanoarchitectures for hybrid few-layers MoS2 with various carbonaceous materials. Here we present the ordered macroporous few-layered MoS2/C hybrid nanoarchitectures via a facile scalable in situ hybridization and spatial confinement strategies. Such hybrid strategies can maximize the MoS2 loading and restriction of MoS2 to a ultrasmall reaction. The optimized as-prepared hierarchical MoS2/C hybrids exhibit an initial capacity up to 631.2 mAh g−1 with a high first columbic efficiency of 81.16% for sodium-ion batteries (BILs) at 200 mA g−1. And, the electrodes display a high reversible capacity of 330.4 mAh g−1 with a long cycle life, superior cycling stability and excellent high-rate performance demonstrated rational designed hybrid architecture using as the electrodes in SIBs. This strategy could be proven to be an effective method for stabilizing the cyclability and improving in rechargeable rate performance for SIBs.

Facile scalable synthesis of highly monodisperse small silica nanoparticles using alkaline buffer solution and their application for efficient sentinel lymph node mapping.

Cancer nanomedicine involving nanotechnology-based drugs and in vivo imaging agents is an active field of nanoscience that provides new ways of enhancing therapeutic and diagnostic efficacy. Translating cancer nanomedicine mainly comes from rational and scalable design of nanoparticles to achieve versatile properties including specific size because nanomaterials whose properties confer unique advantages can only optimize clinical impact. Here, a facile scalable synthesis of highly monodisperse small silica nanoparticles was developed by screening various alkaline buffer solutions as catalysts. The size of silica nanoparticles ranging from 7 to 30 nm was finely controlled by varying the reaction temperature. Moderate sized silica nanoparticles in the range of 30 to 50 nm and large sized silica nanoparticles (>100 nm) were readily synthesized by in situ adding tetraethylorthosilicate (TEOS) and applying the Stöber method in the reaction solution using small silica nanoparticles as the seeds, respectively. Having shown the ability to precisely synthesize size controlled silica nanoparticles with a process compatible with good manufacturing practices, we performed in vivo fluorescence imaging and immunofluorescence analysis of sentinel lymph nodes (SLNs) with the synthesized nanoparticles having different sizes to investigate the size effect for effective identification of SLNs. The synthesized nanoparticles with a diameter of 12 nm showed effective SLN uptake within 10 min after intradermal injection both in noninvasive and in intraoperative imaging mode and were localized evenly inside the SLN, whereas the 120 nm sized nanoparticles failed to identify the SLN with noninvasive imaging at 10 min post-injection and distributed only in the medulla region not in the superficial cortex of the SLN. Taken together, a new facile scalable synthesis technique to achieve fine size controlling capability from very small silica nanoparticles (7 nm) was developed and it made possible to investigate the optimal size of nanoparticles for efficient SLN mapping which is still controversial.

Facile scalable synthesis of MoO2 nanoparticles by new solvothermal cracking process and their application to hole transporting layer for CH3NH3PbI3 planar perovskite solar cells

∼10nm sized MoO2 nanoparticles with high BET surface area of 170.14m2/g were synthesized via scalable new process of combining the ultrasonic spray pyrolysis and solvothermal cracking process. Initially, we synthesized polycrystalline MoO3 microparticles by the ultrasonic spray pyrolysis at 500°C or 600°C. Then the MoO3 microparticles were disassembled into crystalline grains and the grains were subsequently shattered to small MoO2 nanoparticles through the solvothermal polyol reduction process because the polycrystalline MoO3 microparticles are disassembled by thermal expansion and the crystalline MoO3 grains are shattered by volume shrinkage due to phase transition from MoO3 to MoO2. Finally, we applied the MoO2 nanoparticles/toluene solution to new inorganic hole transporting material for planar CH3NH3PbI3 perovskite solar cells. The planar type CH3NH3PbI3 perovskite solar cells exhibited stable efficiency of 14.8% for forward scan condition and 15.5% for reverse scan condition under illumination of 1 Sun (100mW/cm2).

Facile Scalable Synthesis of TiO2/Carbon Nanohybrids with Ultrasmall TiO2 Nanoparticles Homogeneously Embedded in Carbon Matrix.

A facile scalable synthesis of TiO2/C nanohybrids inspired by polymeric dental restorative materials has been developed, which creates ultrasmall TiO2 nanoparticles homogeneously embedded in the carbon matrix. The average size of the nanoparticles is tuned between about 1 and 5 nm with the carbon content systematically increased from 0% to 65%. Imaging analysis and a scattering technique have been applied to investigate the morphology of the TiO2 nanoparticles. The composition, nature of carbon matrix, crystallinity, and tap density of the TiO2/C nanohybrids have been studied. The application of the TiO2/C nanohybrids as lithium-ion battery anode is demonstrated. Unusual discharge/charge profiles have been exhibited, where characteristic discharge/charge plateaus of crystalline TiO2 are significantly diminished. The tap density, cyclic capacities, and rate performance at high current densities (10 C, 20 C) of the TiO2/C nanohybrid anodes have been effectively improved compared to the bare carbon anode and the TiO2/C nanohybrids with larger particle size.

Facile scalable synthesis and superior lithium storage performance of ball-milled MoS2–graphite nanocomposites

A facile high-energy ball-milling method is developed to synthesize MoS2–graphite (MoS2–C) nanocomposites, which can be used for scalable industrial mass production.

Facile scalable synthesis of Co3O4/carbon nanotube hybrids as superior anode materials for lithium-ion batteries

In this report, Co3O4/multiple-wall carbon nanotube (MWCNT) hybrid materials were synthesized via strong ultrasonication-assisted shaking and magnetic stirring processes. The prepared samples were well characterized by utilizing powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy techniques. Results indicated that the resulting Co3O4 nanoparticles were highly dispersed in the MWCNT network backbone and further form Co3O4/MWCNT hybrid materials. The obtained Co3O4/MWCNT hybrids can be employed as anode electrode in Lithium-ion batteries and deliver as high as discharge capacity of 1250mAhg−1 at a current density of 0.2C, additionally, 81% of the discharge capacity for sample 2 with 20wt.% MWCNT loading could be retained after 70 cycles, which could be associated with the specific hybrid structure of the electrode as well as the addition of MWCNT. Most importantly, the present synthetic approach is facile, controllable, and scalable, which allowing it more easily adapted to prepare other hybrid materials with specific architectures.

Amorphous Si/SiOx/SiO2 nanocomposites via facile scalable synthesis as anode materials for Li-ion batteries with long cycling life

Novel Si/SiOx/SiO2 nanocomposites were prepared via a facile and scalable wet synthesis. The amorphous structure, nanoscale particle size, and composition of the Si/SiOx/SiO2 material were characterized and its electrochemical performance as an anode for Li-ion batteries was evaluated. The material shows a stable cycling capacity of ∼600 mA h g−1 over 350 cycles with high coulombic efficiency of >99%.

Facile scalable synthesis of magnetitenanocrystals embedded in carbon matrix as superior anode materials for lithium-ion batteries

A simple and scalable process was developed for the synthesis of highly crystalline magnetite nanocrystals embedded in a carbon matrix using low cost starting materials; the resulting nanocomposite showed a very high specific capacity of 863 mA hg(-1) in the initial cycle and high capacity retention of 90% after 30 cycles.

Facile Scalable Synthesis of Rectorites

Using a synthetic Na-fluorohectorite ([Na0.5]inter[Mg2.5Li0.5]oct[Si4]tetO10F2), mixed-cation heterostructures with an alternating interstratification pattern are formed under appropriate conditions via simple cation-exchange reactions. The most important requirement for the spontaneous formation of these ordered mixed-layer structures is a high degree of charge homogeneity of the smectite. The partial exchange of cations with largely different hydration enthalpies (Na+ by K+) results in the regular interstratification of hydrated (d = 12.4 Å) and nonhydrated (d = 10.0 Å) interlayers at 40% relative humidity (RH). By combining analytical methods that are sensitive to either hydrated or collapsed interlayers (selective cation exchange, hydrosorption isotherms, and 23Na MAS NMR spectroscopy), we proposed a novel mechanism that is centered at the interlayers and does not require polar lamellae, as suggested in the literature for rectorite formation. Upon formation of the regular interstratification, the charge density of the interlayers changes from homogeneous to alternating between interlayers in the stacking direction. This simple redistribution of exchangeable interlayer cations is facile and rapid. The cation exchange capacity (CEC) of the collapsed interlayers is higher than the average CEC, while the CEC of the hydrated interlayers will be correspondingly lower. The local CEC of these interlayers deviates by ∼18%−28% from the average CEC, as calculated independently from ion-exchange experiments and hydrosorption measurements. Moreover, this alternating differentiation of the interlayer cation concentration seems to be driven by thermodynamics. Even a mixture of homocationic Na-hectorite and K-hectorite slowly converts to a regularly interstratified material when immersed in water. After the interlayers are differentiated, they may be selectively manipulated, creating dual functional materials, where distinct nanoreactors are separated by a 1-nm-thick insulating lamellae and are arranged in a regular manner.