Feasible Synthesis Route Research Articles

Valley polarization in a two-dimensional high-temperature semiconducting TiInTe[formula omitted] honeycomb ferromagnet

Exploring valley-contrasting physics in scarce intrinsic high-temperature ferromagnetic semiconductors with feasible synthesis route is of great significance for ever-evolving moden information technology. By first-principles calculations, the TiInTe3 monolayer is predicted to demonstrate excellent structural stability and easy-plane semiconducting ferromagnetism arising from indirect superexchange mechanism. Monte Carlo simulations based on the Heisenberg model reveal a magnetic phase transition at 583 K well above room temperature. Due to the inversion and time-reversal asymmetries, tunable valley polarization in the conduction band up to 110 meV can be achieved by varying the magnetization orientation, which is further validated by a first-order perturbation theory. More excitingly, electron doping for realizing the anomalous valley Hall effect gives rise to an out-of-plane preference for magnetization in the TiInTe3 monolayer and thus generates spontaneous and larger valley polarizations. After doping, the ferromagnetism above room temperature remains robust in the experimentally attainable electron density regime. Our findings highlight that the TiInTe3 monolayer is a promising ferrovalley material for developing high-performance spintronic and valleytronic nanodevices.

Scalable novel lanthanide-ligand complex for robust flexible micro-supercapacitors

Herein we report on the excellent, supercapacitor performance and flexible device application of a robust, new polymeric metal-ligand complex, which is readily synthesized at room temperature via a straightforward, one-step protocol using the N4 donor, namely 3,3′-diaminobenzidine (DAB) and gadolinium(III) nitrate. Thus, the coordination polymer (Gd-DAB) complex synthesized in a facile and economically feasible synthesis route paves the way for realizing a new class of affordable, durable energy devices for storage applications. The results of complementary characterization techniques not only corroborated the proposed structure but also revealed a potential two-dimensional (2D)/sheet-like organization similar to the coordination polymer (COP). The electrochemical tests performed on the as-prepared sample, in the form of an electrode active component, showed brilliant supercapacitive characteristics with the capacitive retention exceeding over 100% even after 5000 cycles. The complex has been used as an active media for the fabrication of an interdigitated flexible and symmetric supercapacitor. The electrochemical storage device evaluation, under different bending angles (up to 180o) and twisting conditions at the current density of 10 μA/cm2 for 5000 cycles, revealed the capacitive retention of ∼50% after 5000 cycles.

Rapid and environment friendly method for acid free iodination of industrially important organics using I2/NaClO3/CH3OH system

I2/NaClO3/CH3OH act as an efficient iodinating agent for many industrially important organics especially those that do not react well with acids. The method can be performed in an acidfree environment, which provides a practical alternative to other procedures avoiding the use of harsh reaction conditions such as high temperatures and pressures, long reaction time and costly metal catalysts. Furthermore, the ambient conditions, simple synthesis procedure and commercially feasible route for synthesis of iodoorganics make the present method more attractive compared to other iodination protocols.

Spark Plasma Sintered Soft Magnetic Composite Based on Fe-Si-Al Surface Oxidized Powders.

Soft magnetic composites (SMCs) need a stable matrix to apply heat treatments for enhancing their magnetic characteristics. A stable matrix can be offered by alumina, but the densification of the ferromagnetic particles covered by this oxide (by sintering) can be very difficult. This paper proposes a feasible synthesis route for obtaining alumina matrix SMCs. An Fe-Si-Al alloy with nominal composition Fe85Si9Al6 was obtained by mechanical alloying of elemental Fe, Si, and Al powders, and further, the as-milled powders were superficially oxidized by immersion in HCl solution. The oxide layer was composed of iron, silicon, and aluminum oxides, as the Fourier-transform infrared spectroscopy technique revealed. The Fe-Si-Al@oxide powder was densified by the spark plasma sintering technique-SPS. Upon sintering, a continuous matrix of oxide (mainly alumina) was formed by the reaction of the Fe-Si-Al powder coreswith their oxide layer. The main part of the composite compacts after sintering consisted of an Fe3Si-ordered phase dispersed in an oxide matrix. The DC and AC tests of magnetic composite compacts showed that upon increasing the sintering temperature, the density, magnetic induction, and magnetic permeability increased. The initial magnetic permeability was constant in the entire range of testing frequencies and the magnetic losses increased linearly. The stability of the magnetic characteristics in frequency is promising for developing further such types of magnetic composite.

Box-Behnken experimental design for optimizing process parameters in carbonate-promoted direct thiophene carboxylation reaction with carbon dioxide

A feasible synthesis route is developed for achieving the direct carboxylation of thiophene and CO 2 in a relatively mild solvent-free carboxylate-assisted carbonate (semi) molten state. The effects of reaction factors on the carboxylate yield are investigated in the preliminary screening experiments, and the phase behavior analysis of the reaction medium is detected through the thermal characterization analysis of in-situ high temperature X-ray diffraction measurement ( in-situ XRD). The application of response surface methodology (RSM) based on the Box-Behnken design (BBD) is conducted to investigate the effect of the reaction parameters, such as reaction temperature, carbonate proportion, CO 2 pressure and thiophene amount, on the product yield. The regressed second-order polynomial model equation well correlates all the independent variables. The analysis of variance (ANOVA) results reveal that the quadratic effect of reaction temperature is the most effective parameter in this carboxylation reaction owing to it’s the highest contribution to the sum of square (30.18%). The optimum reaction conditions for maximum product yield are the reaction temperature of 287 ℃, carbonate proportion of 32.20%, CO 2 pressure of 10 bar and thiophene amount of 9.35 mmol. Operating under these selected experimental conditions, a high product yield (50.98%) can be achieved.

Easy enrichment of graphitic nitrogen to prepare highly catalytic carbons for oxygen reduction reaction

One of the biggest challenges in producing fuel cells at affordable prices is to synthesize carbon materials selectively doped with graphitic nitrogen, as it is considered the most active nitrogen species for the oxygen reduction reaction (ORR). So far, all strategies focus on the use of nitrogen-containing carbon precursors, which limits the functionalization of commercially available carbon materials. Here, we present a post-functionalization method to boost the catalytic properties of carbon materials for the ORR by selectively enriching activated carbons with nitrogen graphitic species. A commercial high-surface area activated carbon was post-functionalized by a two-step procedure. First, the commercial carbon was mixed with different carbon/urea weight ratios and heated in air at 350 °C. Then, the functionalized materials were heat-treated at high temperature (from 700 to 1300 °C) to tailor the amount and distribution of the different nitrogen species in the resulting carbon structure. Nitrogen functionalization using a carbon to urea weight ratio of 1:2 and heat-treatment at 1100 °C led to highly selective doping in graphitic nitrogen species, which provided the tools to individually asses the catalytic activity of these nitrogen species. In addition, this study presents a low-cost and easily feasible synthesis route to improve the catalytic activity of carbon materials, leading to an onset potential of almost 0.9 V compared to reversible hydrogen electrode for ORR in an alkaline electrolyte. Moreover, this study provides significant evidence for the key role of graphitic nitrogen.

High-Entropy Perovskite Fluorides: A New Platform for Oxygen Evolution Catalysis.

High-entropy perovskite fluorides (HEPFs) have great potential in electrocatalysis that has not been realized because of the limitation of a high-temperature synthetic route and the limited understanding of high-entropy materials. The use of HEPFs in effective oxygen evolution catalysis and a feasible synthesis route for HEPFs in a boiled solution by combining a hydrothermal method with mechanochemistry are first reported here. These HEPFs consisting of cost-effective elements dramatically gave excellent catalytic activity for the oxygen evolution reaction in an alkaline media.

Synthesis of ultra-fine iron powder by combining the flame aerosol synthesis and postreduction

Abstract

Optoelectronic and photoacoustic studies of an organic dye synthesized through green route

An azo dye was prepared through an environmentally benign and economically feasible synthesis route with cardanol as a starting material. Cardanol is a cost-effective and renewable natural source obtained from Cashew Nut Shell Liquid, a by-product of the cashew industry. The dye was spectrally characterized by IR, UV-Vis, NMR and fluorescence studies. UV-Vis absorption showed a bathochromic shift between solvents of lower and higher polarities. Nonlinear optical and photoacoustic properties were studied using a frequency doubled Nd:YAG laser producing 532 nm laser pulses of 3 ns pulse width. Results show that the nonlinear absorption coefficient decreases with the increase of on-axis intensity, suggesting excited state absorption as the principal mechanism. The observed nonlinearity has applications in optoelectronics.

Crossed Aldol Condensation (CAC) as a Feasible Route for Synthesis of a 1, 2-Unsaturated Carbonyl Compound-1,3 Diphenylpropenone

We here report an optimized crossed aldol method for synthesis of 1,2-unsaturated carbonyl compound, 1,3-diphenylpropenone (82-93% yield) rely on alcoholic base assisted condensation of arylmethyl ketone with aromatic aldehydes. The method simply follows the conventional synthetic route however an extraordinary control over various reaction parameters enhance its synthetic practicability. Furthermore, a comparative study has been done to explore the scope for synthesis of 1,3-diphenylpropenone by crossed aldol reaction by solvent assisted method (SAM) and solvent-less method (SLM). Undeniably, solvent-less technique (90-95% yield) hold superiority however tuning of certain reaction parameters, leveled-up solvent assisted crossed aldol reaction, but not to an analogues platform.

Three Dimensional Metallic Carbon from Distorting sp3-Bond

Owing to the outstanding properties of metallic carbon as well as their great potential applications, design and synthesis of metallic carbon have long attracted considerable attention. In this work, a new three-dimensional metallic carbon (dubbed as Tri-C9) has been built by distorting the sp3 hybridization bond. Our first-principles calculations results indicate that Tri-C9 is a metastable metallic carbon, and that the metallic behavior of Tri-C9 originates from the π bonds near Fermi level. This study offers a new way to design all-sp3 hybridized metallic carbon via distorting the sp3-bond. In addition, a feasible synthesis route for Tri-C9 has been proposed by compressing graphite.

First-Principles Calculations on Electronic Structures of N/V-Doped and N-V-Dodoped Anatase TiO2(101) Surfaces

The energetic and electronic properties of N/V-doped and N-V-codoped anatase TiO(2) (101) surfaces are investigated by first-principles calculations, with the aim to elucidate the relationship between the electronic structure and the photocatalytic performance of N-V-codoped TiO(2). Several substitutional and interstitial configurations for the N and/or V impurities in the bulk phase and on the surface are studied, and the relative stability of different doping configurations is compared by the impurity formation energy. Systematic calculations reveal that N and V impurities can be encapsulated by TiO(2) to form stable structures as a result of strong N-V interactions both in the bulk and the surface model. Through analyzing and comparing the electronic structures of different doping systems, the synergistic doping effects are discussed in detail. Based on these discussions, we suggest that N(O)V(Ti) codoping cannot only narrow the band gap of anatase TiO(2), but also forms impurity states, which are propitious for the separation of photoexcited electron-hole pairs. In the case of N(O)V(Ti) -codoped TiO(2) (101) surfaces, this phenomenon is especially prominent. Finally, a feasible synthesis route for N(O)V(Ti) codoping into anatase TiO(2) is proposed.

Growth analysis of novel ZnO nanotetrapods with tubular legs from aspect of reagent’s vapor pressure and growth temperature

In this article, novel ZnO nanotetrapods with tubular legs was successfully synthesized using mixed powder of Zn, ZnO, and carbon as source. The growth process was analyzed at large, and a two-step growth model, viz. initial deficient-oxidation and latter second-volatilization, was proposed to explain the formation of tubular leg of ZnO nanotetrapod. In the growth model, the high Zn vapor pressure and high growth temperature were considered as two crucial factors determining the growth behavior. Zn-rich ZnO nanotetrapod formed under high Zn vapor pressure at the initial stage. These redundant Zn clusters coexisted in ZnO lattice as interstitial Zn. The following second-volatilization of interstitial Zn under high growth temperature led to formation of tubular leg. Four other experiments were designed to analyze the growth behavior under high and low Zn vapor pressure and growth temperature, respectively, and these experimental results further confirmed the validity of our growth model. Our experiment proposed a feasible synthesis route to prepare hollow nanostructures controlled by the vapor pressure and growth temperature. Furthermore, these novel ZnO nanotetrapods might have potential application as building blocks for functional nanodevices.

SUBSTITUTED POLYACETYLENES BY CYCLOPOLYMERIZATION : POLY (1, 6-HEPTADIYNE) AND POLY (PROPIOLIC ANHYDRIDE)

Two substituted polyacetylenes, poly(l,6-heptadiyne) and poly(propiolic anhydride), have been synthesized by cyclopolymerization of diacetylenic precursors. The former polymer has been examined in some detail. Under suitable conditions, it can be doped to a conductivity(σ) of ~ 1 s/cm. It displays a number of contrasts to polyacetylene in its morphology, lack of crystallinity, and electron spin resonance behavior. Poly(propiolic anhydride) has been examined only in a preliminary manner ; however, this system offers the possibility for generation of a range of substitutents by facile modification of the starting monomer or the product polymer. Cyclopolymerization is a feasible route for synthesis of a family of conducting polymers.