One-step Solid-phase Synthesis Research Articles

Enhanced Cathode Performance: The Heterostructure Construction of LiCoO2@Co3O4@Li6.4La3Zr1.4Ta0.6O12.

In this study, the heterostructure cathode material LiCoO2@Co3O4@Li6.4La3Zr1.4Ta0.6O12 was prepared by coating Li6.4La3Zr1.4Ta0.6O12 on the surface of LiCoO2 through a one-step solid-phase synthesis. The morphology, structure, electrical state, and elemental contents of both pristine and modified materials were assessed through a range of characterization techniques. Theoretical calculations revealed that the LCO@LLZTO material possessed a reduced diffusion barrier compared to LiCoO2, thereby facilitating the movement of Li ions. Electrochemical tests indicated that the capacity retention rate of the modified cathode composites stood at 70.43% following 300 cycles at a 2C rate. This high rate occurred because the Li6.4La3Zr1.4Ta0.6O12 film on the surface enhanced the migration of Li+, and the spinel phase of Co3O4 had better interfacial stability to alleviate the generation of microcracks by inhibiting the phase change from the layered phase to the rock-salt phase, which considerably improved the electrochemical properties.

One-step solid-state synthesis of NixPy @C nanocomposites for high-performance hybrid supercapacitor

Transition metal phosphides and their composites are very attractive ascribing to their prominent performance in electrochemical energy storage devices, which are generally prepared by cumbersome and time-consuming liquid-phase synthesis methods. In this work, a convenient and efficient one-step solid-phase synthesis method (SPS) is successfully developed for the preparation of NixPy @C nanocomposites under the ambient atmosphere. By controlling the synthesizing temperature, carbon-coated Ni2P, Ni5P4, and NiP2 nanocomposites can be facilely synthesized. The solid-phase synthesized NixPy @C nanocomposites exhibit high charge storage capability and good cycle stability. A high specific capacity of over 197.2 mAh g−1 (709.9 C g−1) is achieved at a current density of 1 A g−1 for the optimal nanocomposite NiP2 @C, and more than 84.3% of initial specific capacitance is kept after 1000 cycles. The assembled hybrid supercapacitor device based on the nanocomposite NiP2 @C and an interconnected hierarchical porous carbon (NiP2 @C//IHPC) delivers specific energy of up to 50.38 Wh kg−1 at the specific power of 0.89 kW kg−1, which value still reaches 29.1 Wh kg−1 at a high specific power of 9.44 kW kg−1. More than 83.8% of initial specific capacity is retained after 20,000 cycles. Compared with the other nickel-based phosphides and their composites prepared by other methods, the prepared NixPy @C nanocomposites by the developed one-step SPS method demonstrate very competitive performance with the distinguished merits of convenient, efficient, target-oriented, cost-efficiency, and eco-friendly. The successfully developed solid-phase synthesis method is proved to be a reliable strategy for facile preparation of TMPs with high performance.

Nitrogen-doped fluorescence carbon dots as multi-mechanism detection for iodide and curcumin in biological and food samples

Iodine ion is one of the most indispensable anions in living organisms, particularly being an important substance for the synthesis of thyroid hormones. Curcumin is a yellow-orange polyphenol compound derived from the rhizome of Curcuma longa L., which has been commonly used as a spice and natural coloring agent, food additives, cosmetics as well as Chinese medicine. However, excess curcumin may cause DNA inactivation, lead to a decrease in intracellular ATP levels, and trigger the tissue necrosis. Therefore, quantitative detection of iodine and curcumin is of great significance in the fields of food and life sciences. Herein, we develop nitrogen-doped fluorescent carbon dots (NCDs) as a multi-mechanism detection for iodide and curcumin in actual complex biological and food samples, which was prepared by a one-step solid-phase synthesis using tartaric acid and urea as precursors without adding any other reagents. An assembled NCDs-Hg2+ fluorescence-enhanced sensor for the quantitative detection of I− was established based on a fluorescence “turn-off-on” mechanism in a linear range of 0.3–15 μM with a detection limit of 69.4 nM and successfully quantified trace amounts of I− in water samples and urine sample. Meanwhile, the as-synthesized NCDs also can be used as a fluorescent quenched sensor for curcumin detection based on the synergistic internal filtration effect (IFE) and static quenching, achieving a good linear range of 0.1–20 μM with a satisfactory detection limit of 29.8 nM. These results indicate that carbon dots are potential sensing materials for iodine and curcumin detection for the good of our health.

One-step solid-phase synthesis of binder-free molybdenum disulfide/carbon fibers paper anode for high-performance lithium-ion batteries

A facile one-step solid-phase synthesis strategy is developed for synthesizing a binder-free molybdenum disulfide/carbon fibers paper (MoS2/CFP) anode. The microstructure, composition, morphology and electrochemical performances were investigated. It is found that the thin MoS2 layers are well anchored on the interlaced carbon fibers to form MoS2/CFP, which has mesoporous structure and large specific surface area of ∼18.8 m2g-1. As a result, the obtained MoS2/CFP anode exhibits a reversible capacity of 261 mAh·g−1 with 31.2% loading ratio of MoS2. After subtracting the capacity of CFP, the MoS2 in the composite anode delivers a reversible capacity of 539 mAh·g−1 and shows better cycle stability than commercial MoS2 after 100 cycles at 100 mA g−1. The remarkable electrochemical performances could be attributed to the buffer space among carbon fibers for the volume changes of MoS2 as well as the highly conductive carbon fibers network, suggesting that the MoS2/CFP is a promising binder-free anode for lithium-ion batteries.

A Reusable N-Doped-Carbon-Coated Mo2 C Composite Counter Electrode for High-Efficiency Dye-Sensitized Solar Cells.

The design and development of efficient and stable nonprecious-metal-based catalysts for counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) has received a great deal of attention. In this work, molybdenum carbide nanoparticles homogeneously distributed in a nitrogen-rich carbon matrix (Mo2 C@NC) have been synthesized from inexpensive raw materials (polyoxometalate and dicyandiamide) by a facile one-step solid-phase synthesis method. The novel Mo2 C@NC hybrid was not only used as a CE in a DSSC, but also showed superior catalytic activity towards I3- /I- as a redox electrolyte. The power conversion efficiency of a DSSC with Mo2 C@NC as the CE was as high as 6.49 %, comparable to that with Pt (6.38 %). The CE was prepared by a drop-coating method, without the addition of another conductive polymer. Most importantly, the method circumvents the problem of the sample falling off from the fluorine-doped tin oxide (FTO), and the CE could be repeatedly reused with unchanged efficiency. Therefore, it opens the way for the development of platinum-free catalysts with low cost, simple processing, good stability, and high efficiency.

Low-temperature one-step solid-phase synthesis of carbon-encapsulated TiO2 nanocrystals as anode materials for lithium-ion batteries

A simple and highly efficient method is developed for in situ one-step preparation of carbon co-encapsulated anatase and rutile TiO2 nanocrystals (TiO2@C) with core-shell structure for lithium-ion battery anode. The synthesis is depending on the solid-phase reaction of titanocene dichloride with ammonium persulfate in an autoclave at 200 °C for 30 min. The other three titanocene complexes including bis(cyclopentadienyl)dicarbonyl titanium, cyclopentadienyltitanium trichloride, and cyclopentadienyl(cycloheptatrienyl)titanium are used instead to comprehensively investigate the formation mechanism and to improve the microstructure of the product. The huge heat generated during the explosive reaction cleaves the cyclopentadiene ligands into small carbon fragments, which form carbon shell after oxidative dehydrogenation coating on the TiO2 nanocrystals, resulting in the formation of core-shell structure. The TiO2 nanocrystals prepared by titanocene dichloride have an equiaxed morphology with a small diameter of 10–55 nm and the median size is 30.3 nm. Hundreds of TiO2 nanocrystals are encapsulated together by the worm-like carbon shell, which is amorphous and about 20–30 nm in thickness. The content of TiO2 nanocrystals in the nanocomposite is about 31.1 wt.%. This TiO2@C anode shows stable cyclability and retains a good reversible capacity of 400 mAh g−1 after 100 cycles at a current density of about 100 mA g−1, owing to the enhanced conductivity and protection of carbon shell.

Growth mechanism and magnetic properties of monodisperse L1(0)-Co(Fe)Pt@C core-shell nanoparticles by one-step solid-phase synthesis.

In this report, we present a novel one-step solid-phase reaction method for the synthesis of L10-CoPt@C core-shell nanoparticles (NPs) using organic metal precursors without surfactants. The obtained CoPt@C NPs have a good face-centered tetragonal single crystal structure and regular shape. The mean size of CoPt is 14 nm with a uniform carbon shell. The evolution of the core-shell structure during the synthesizing process is investigated in detail. Firstly organic metal precursors are decomposed, followed by the formation of grains/clusters in a metal-carbon intermediate state. Then the metal-carbon small grains/clusters agglomerate and recrystallize into single crystal metal alloy NPs covered with a carbon layer. The carbon shell is effective in preventing the coalescence of L10-CoPt NPs during high temperature sintering. The prepared L10-FePt nanoparticles have a high coercivity of up to 12.2 kOe at room temperature. This one-step solid-state synthesizing method could also be employed for the preparation of other types of nanostructures with high crystallinity, monodispersity and chemically ordered phase.

Solid-phase synthesis and catalytic sweetening performance of sulfonated cobalt phthalocyanine from sulfonated phthalic anhydride mixture

A relatively green, efficient and economical synthetic route for the one-step solid-phase synthesis of sulfonated cobalt phthalocyanine from sulfonated phthalic anhydride mixture was studied, and could solve the serious problems of waste acid pollution and the low utilization of materials in the direct sulfonation of phthalocyanine. The optimal reaction conditions were using a phthalic anhydride mixture with a sulfonation degree of 60% as the raw material, a ratio of urea to PA–SPA mixture of 4 : 1, a ratio of cobalt chloride to PA–SPA mixture of 1 : 4, ammonium molybdate (1 wt%) as catalyst, and carrying out the reaction at 260 °C for 3 hours. Under these optimal conditions, a yield of 52.9% can be achieved. Through sweetening experimental studies, the synthesized sulfonated cobalt(II) phthalocyanine had better sweetening performance than the industrial catalysts, in both the liquid–liquid sweetening and fixed bed sweetening experiments. A sweetening rate of 93% can be achieved in 20 min with the synthesized catalyst in a fixed bed.

Facile one-step solid-phase synthesis of multitopic organic–DNA hybrids via “click” chemistry

Small molecule–DNA hybrids can be synthesized in a one-pot fashion and in good yields by coupling multiazide cores to alkyne-modified DNAs on a solid support using click chemistry.

One-step solid-phase synthesis of ultrasmall homogeneous face-centered tetragonal FePt nanoparticles encapsulated in thin carbon shells

Discrete, homogenous and ultrasmall (mostly 2–4 nm) L10-ordered fct FePt nanoparticles encapsulated in well-graphitized thin carbon shells have been prepared by a one-step solid-phase synthesis technique, which can be applied for the production of a number of metal alloy nanoparticles encapsulated in carbon shells. The as-synthesized FePt@C nanoparticles of size 2.1 ± 0.4 nm present superparamagnetic properties at room temperature. The 3.3 ± 0.6 nm size FePt@C nanoparticles have a high coercivity, up to 4.56 kOe at room temperature, and superior chemical stability in a high concentration HCl (10 M) solution. Furthermore, these nanoparticles functionalized non-covalently by phospholipid-poly(ethylene)glycol show biocompatibility with the tested cells (mouse macrophage and mouse L929 fibroblasts cells) in all test concentrations (0.025–0.2 mg mL−1).

Facile solid-phase synthesis of the diammoniate of diborane and its thermal decomposition behavior

The recent mechanistic finding of the hydrogen release pathways from ammonia borane (AB) has sparked new interest in the chemistry and properties of the diammoniate of diborane (DADB), an ionic isomer of AB. We herein report a facile one-step solid-phase synthesis route of DADB using inexpensive starting materials. Our study found that mechanically milling a 1 : 1 NaBH(4)/NH(4)F powder mixture causes the formation of crystalline DADB via a NH(4)BH(4) intermediate. The produced DADB can be readily separated from the sodium fluoride (NaF) by-product by a purification procedure using liquid ammonia at -78 °C. The thermal decomposition behavior of DADB was studied using synchronous thermal analyses, particularly in comparison with AB. It was found that the decomposition steps and products of DADB are similar to those of AB. But meanwhile, DADB exhibits a series of advantages over AB that merit its potential hydrogen storage application, such as lower dehydrogenation temperature, free of foaming and lack of an induction period in the thermal decomposition process. Our study further found that the volatile non-hydrogen products from DADB can be effectively suppressed by milling with MgH(2).

Chemical synthesis of MT1 and MT7 muscarinic toxins: critical role of Arg-34 in their interaction with M1 muscarinic receptor.

Two muscarinic toxins, MT1 and MT7, were obtained by one-step solid-phase synthesis using the 9-fluorenylmethoxycarbonyl-based method. The synthetic and natural toxins, isolated from the snake venom or recombinantly expressed, display identical physicochemical properties and pharmacological profiles. High protein recovery allowed us to specify the selectivity of these toxins for various muscarinic receptor subtypes. Thus, sMT7 has a selectivity for the M1 receptor that is at least 20,000 times that for the other subtypes. The stability of the toxin-receptor complexes indicates that sMT1 interacts reversibly with the M1 receptor, unlike sMT7, which binds it quasi-irreversibly. The effect of the synthetic toxins on the atropine-induced [3H]N-methylscopolamine (NMS) dissociation confirms that sMT7 targets the allosteric site on the M1 receptor, whereas sMT1 seems interact on the orthosteric one. The great decreases in the binding potencies observed after the R34A modification in sMT1 and sMT7 toxins highlight the functional role of this conserved residue in their interactions with the M1 receptor. Interestingly, after the R34A modification, the sMT7 toxin binds reversibly on the M1 receptor. Furthermore, the potency of sMT7-R34A for the NMS-occupied receptor is lower compared with unmodified toxin, supporting the role of this residue in the allosteric interaction of sMT7. All these results and the different charge distributions observed at the two toxin surfaces of their structure models support the hypothesis that the two toxins recognize the M1 receptor differently.