Liquid-phase Synthesis Research Articles

Fast Solution-Phase and Liquid-Phase Peptide Syntheses (SolPSS and LPPS) Mediated by Biomimetic Cyclic Propylphosphonic Anhydride (T3P®).

The growing applications of peptide-based therapeutics require the development of efficient protocols from the perspective of an industrial scale-up. T3P® (cyclic propylphosphonic anhydride) promotes amidation in the solution-phase through a biomimetic approach, similar to the activation of carboxylic moiety catalyzed by ATP-grasp enzymes in metabolic pathways. The T3P® induced coupling reaction was applied in this study to the solution-phase peptide synthesis (SolPPS). Peptide bond formation occurred in a few minutes with high efficiency and no epimerization, generating water-soluble by-products, both using N-Boc or N-Fmoc amino acids. The optimized protocol, which was successfully applied to the iterative synthesis of a pentapeptide, also allowed for a decrease in the solvent volume, thus improving process sustainability. The protocol was finally extended to the liquid-phase peptide synthesis (LPPS), where the isolation of the peptide was performed using precipitation, thus also showing the suitability of this coupling reagent to this emerging technique.

Enhanced electrochemistry stability of oxygen doped Li6PS5Cl argyrodite solid electrolyte by liquid-phase synthesis

The argyrodite solid electrolyte Li6PS5Cl is one of the promising candidates due to its high Li-ion conductivity for the application of all-solid-state lithium-ion batteries (ASSLIBs). Unfortunately, Li6PS5Cl argyrodite exhibits low stability against lithium metal anodes and oxide cathodes. One way to improve stability is by oxygen doping into Li6PS5Cl argyrodite. In this work, Li6PS5–2.5xO2.5xCl (x = 0, 0.05, and 0.10) solid electrolytes with oxygen doping were successfully synthesized using liquid-phase synthesis for the first time. Therefore, the solid electrolyte with x = 0.05 exhibits high ionic conductivity with enhanced electrochemical stability against lithium metal and oxide cathodes. Argyrodites with x = 0.05 and x = 0.10 show superior capacity retention and higher Coulomb efficiency compared to x = 0. Moreover, the solid electrolytes also demonstrate better stability during Li symmetrical cell measurements. This experiment provides a controllable amount of oxygen doping into the Li6PS5Cl argyrodite solid electrolyte system in order to achieve high performance of ASSLIBs through liquid-phase synthesis.

Synthesis and characterization of the sea urchin-like γ-AlOOH/Fe3O4@SiO2 nanosorbent with ultra-high performance of Congo red removal

To manifest the benefits of nanosorbents in microstructure, the strong magnetism of Fe3O4 nanospheres is fully utilized to realize the rapid solid–liquid separation of adsorbent and aqueous solution. A sea urchin-like magnetic composite nanosorbent with a hierarchical structure was successfully manufactured by a simple and efficient liquid-phase hydrothermal synthesis method. Furthermore, its graded structure can sufficiently enhance the porosity and Zeta potential value of the material to increase the adsorption site and adsorption force between the material and CR molecular. The synthesized nanosorbent was then explored by a series of material physical and chemical characterization tools. It can be illustrated that the adsorbent is a strong magnetic composite nanomaterial with uniform particle size distribution and high dispersion, and is based on Fe3O4@SiO2 smooth nanoparticles as the inner core and γ-AlOOH as the shell. The saturation adsorption capacity reached 4534.57 mg g−1 with due expedition (under the adsorbent mass of 50 mg, CR mass concentration of 1500 mg/L, temperature of 25 °C and solution pH value of 3), whereas the γ-AlOOH of 925.34 mg g−1, Fe3O4 of 41.25 mg g−1 and Fe3O4@SiO2 of 93.21 mg g−1. After eight cycles of adsorption tests, the saturation capacity could still maintain 94.46% of the original adsorption capacity. Moreover, the adsorbent could be recovered by a simple applied magnetic field and the whole adsorption process conforms to the Pseudo-second kinetic model and the Langmuir isotherm model. Therefore, the sea urchin-like magnetic composite nanomaterials with a graded structure synthesized in this study could be widely utilized as a potential adsorbent material for CR removal.

Ho3+-doped Y3NbO7 transparent ceramic elaborated by air pre-sintering and post-HIP treatment as potential LASER gain material at 2 μm

In the framework of the development of new laser materials at the lowest limit of the mid-IR range, the cubic Y3NbO7 matrix has been doped by trivalent holmium. Fine powders were prepared through a liquid phase synthesis and highly densified using a two-stage sintering process: i) natural sintering was performed in air to reach relative density higher than 95%; ii) Hot Isostatic Pressure was applied to obtain fully dense and, consequently, transparent ceramics. The resulting microstructures were examined and then related to sintering parameters such as temperature and pressure. Refractive index, transmission and luminescence properties were measured and presented for the first time on a bulk material. These encouraging results showed that the Ho3+-doped Y3NbO7 compound is a promising potential candidate as a new laser material.

Dimeric imidazole-type ionic liquid supported oligosaccharide synthesis

A strategy for rapidly and effectively assembling oligosaccharides using a novel dimeric imidazole-type ionic liquid has been developed. This method incorporating the advantages of both solid- and liquid-phase synthesis, can not only maintain the homogeneous reaction conditions, but also facilitate the phase separation process with extremely high recovery of products. The effectiveness of this approach was verified through the successful synthesis of β-(1 → 6)-linked triglucosamine with an overall yield of 61.6%.

Highly active and durable PdFe/Cu nanocatalysts prepared by liquid phase synthesis for ethanol electrooxidation reaction

In the face of environmental pollution and an energy shortage, how to reduce the cost of a noble metal catalyst in clean energy such as the fuel cell system and improve its electrocatalytic performance is one of the hot issues in this field. Here, a facile stepwise co-reduction route for synthesizing a series of PdFe/Cu catalysts with surface reconstruction is investigated and the ethanol oxidation reaction (EOR) performance is explored. The greater exposure of Pd active sites makes it excellent in EOR in alkaline media compared to the homemade and commercial Pd black catalyst. The mass activity of PdFe/Cu (794.97 mA mg−1Pd) is 2.52 times that of the Pd black catalyst (315.64 mA mg−1Pd). This kind of PdFe/Cu catalyst shows enhanced mass current density (255.66 mA mg−1Pd) after the 1800 s chronoamperometry test and only exhibits a decay of 1.4% after accelerated 500-cycle measurement. The enhanced EOR performance may be due to the change in the electronic structure of Pd caused by synergistic and strain effects among Pd, Fe, and Cu. This work provides an effective and kindly strategy to synthesize electrocatalysts with superior activity and durability in relation to EOR.

Colloidal Synthesis and Photoluminescence Property of Near-IR-Responsive Ag8GeS6 Quantum Dots

Semiconductor nanocrystals of a few nanometers in size, called quantum dots (QDs), exhibit unique photochemical properties due to quantum size effect. In recent years, high-quality near-infrared responsive QDs such as CdTe and PbS have been used for wide-ranged applications from light-energy conversions to biomedical applications. However, the contents of highly toxic elements, Cd and Pb, restrict their practical use. On the other hand, group IV-based multinary compound semiconductors, such as Ag2ZnSnS4, Ag8SnS6, and Ag8GeS6, have attracted much attention because of their less toxicity and light absorption property in visible and near-IR region. However, there are only a few reports to prepare size-quantized nanocrystals for tuning their photoelectrochemical properties. In this study, we report the preparation of Ag8GeS6 core and Ag8GeS6@ZnS core/shell QDs using a feasible liquid-phase chemical synthesis method.As a moisture and air stable Ge precursor, Ge(gly)2(H2O)2 was prepared by the literature method with slight modification[1]. Precursor powders of Ge(gly)2(H2O)2, silver(I) diethyldithiocarbamate, and thiourea were dispersed in a mixture solvent of 1-dodecanethiol and oleylamine, followed by the heat treatment at 423 K for 20 min. Thus-obtained QDs were isolated from the reaction solution by the addition of methanol and ethanol as a non-solvent. Then, the obtained QDs were finally dispersed in chloroform. The obtained Ag8GeS6 QDs were further surface-coated with thin ZnS layer to form Ag8GeS6@ZnS core/shell QDs.The onset wavelengths in the absorption spectra of Ag8GeS6 and Ag8GeS6@ZnS were observed at 850 nm and 830 nm, respectively. The XRD analysis showed that the obtained nanocrystals had an orthorhombic Ag8GeS6 crystal structure. TEM measurements revealed that the prepared Ag8GeS6 QDs had an average particle size of 4.53 nm while that of Ag8GeS6@ZnS was 5.80 nm. From the difference between the sizes before and after ZnS coating, we estimated the ZnS shell thickness of Ag8GeS6@ZnS to 0.63 nm. The energy gap of Ag8GeS6 QDs was slightly decreased from 1.45 eV to 1.37 eV with an increase in Ge/(Ge+Ag) ratio. Ag8GeS6 QDs with Ge/(Ge+Ag) = 0.8 exhibited a broad photoluminescence (PL) peak at 850 nm with PLQY of about 25%. The surface coating with ZnS remarkably increased the PLQY to 65%, which was considerably high in comparison to those of near-IR-emissive multinary QDs in our previous papers such as Ag–In–Ga–Se and Ag–In–Ga–S–Se QDs [2,3]. Thus, the present Ag8GeS6@ZnS QDs seem to be a promising probe for bio-imaging with near-IR photoluminescence.[1] A.S.R. Chesman, et al., Chem. Mater, 26, 5726 (2014).[2] T. Kameyama, et al., ACS Appl. Nano Mater, 3, 3275-3287 (2020).[3] N. Rismaningsih, et al., J. Mater. Chem. C, 9, 12791-12801 (2021).

Boosting the inherent activity of NiFe layered double hydroxide via erbium incorporation for water oxidation.

Enhancing the inherent activity of transition metal-based compounds involving Ni and Fe for the electrocatalytic oxygen evolution reaction (OER) is of vital importance, especially NiFe layered double hydroxide (LDH). Here, we doped erbium (Er) into NiFe LDH (Er-NiFe LDH) nanostructures using simple liquid-phase synthesis. The OER activity tests at the same mass loading demonstrated that Er-NiFe LDH has a smaller overpotential and lower Tafel slope than undoped NiFe LDH and commercial RuO2 powders, needing only a small overpotential of 243mV to achieve a constant current at 10mAcm-2. Additionally, Er-NiFe LDH was grown in situ on hydrophilic carbon paper substrates (Er-NiFe LDH@CP) to fabricate a three-dimensional (3D) electrode with large catalyst loading, which is favorable for analyzing the stability of morphology structure and elementary components after OER measurement. The galvanostatic measurement suggested that the Er-NiFe LDH@CP electrode possess higher electrochemical durability than a modified glassy carbon electrode due to the stronger mechanical binding between Er-NiFe LDH nanostructures and carbon paper substrate. More importantly, physical characterizations (e.g., SEM and XPS) revealed that Er-NiFe LDH has an excellent stability of morphology, and Ni, Fe, and Er still exist on the catalyst 24h after the operation. This work provides an effective way for improving the inherent catalytic activity and stability of polymetallic OER catalysts in the future.

A Super Uniform Hydrophobic Gas Diffusion Layer for a Proton Exchange Membrane Fuel Cell.

The design and optimization of the gas diffusion layer (GDL) play a crucial role in the improvement of proton exchange membrane fuel cell performance. Hydrophobic treatment of a GDL is an important method for facilitating mass transfer, while conventional Teflon treatment is not uniform and leads to an increase in ohmic and heat resistance. Herein, a homogeneous molecular hydrophobic GDL was prepared by liquid phase synthesis, and a two-dimensional non-isothermal model was developed to investigate the transfer mechanism. The peak power density of cells with the GDL described above was improved by 46% compared to that of the conventional GDL. The ohmic and mass transport resistance decreased by 15% and 52%, respectively, under a current density of 1 A cm-2 using the uniform hydrophobic GDL. The simulation results proved that the uniform hydrophobic GDL eliminates the hydrophilic dots, which prevents the formation of water pools and reduces the resistance to gas flow. The water saturation of the conventional GDL reaches 0.19 at a current density of 1 A cm-2, and the saturation of a modified GDL under the same conditions is only 0.13. A dimensionless parameter, Tf, is proposed to characterize the resistance of oxygen diffusion. In conclusion, molecular-level uniform hydrophobic treatment can effectively reduce the ohmic and mass transfer resistance of a GDL and effectively improve the performance of fuel cells.

PdO-modified ZnSnO3 hollow rounded cubes for high-performance TEA gas sensors at low temperature

Given human health and environmental safety issues, it is particularly imperative to detect triethylamine (TEA) rapidly and effectively at low temperatures. In this work, ZnSnO3 hollow rounded cubes (HZTO) with different PdO contents were prepared by liquid phase synthesis methods. The characterization results show that the side length of the hollow-rounded cubes is 500 – 700 nm, and the thickness is about 50 nm. Synthetic materials were applied to TEA gas sensors, and the sensing characteristics of the sensors were evaluated. The gas sensing results indicate that the modification of PdO can adjust the optimal operating temperature and the response of the gas sensor. The response value of the sensor with the best gas sensing performance can be as high as 532 to 100 ppm TEA at 175 °C, which is 17 times that of the unmodified material, and the working temperature is reduced by 125 °C. In addition, the sensor has good performance in selectivity, response time (1 s), low detection limit (500 ppb), and long-term stability. The improved TEA gas sensing performance is attributed to the structural characteristics of the hollow rounded cube of the material, p-n heterojunction, and the catalytic effect of PdO.

2. Formation and Production of Powder and Particles 2.2 Particle Synthesis in Liquid Phase 2.2.4 Solution Synthesis of Metal Nanoparticles Using Chemical Reduction Method

2. Formation and Production of Powder and Particles 2.2 Particle Synthesis in Liquid Phase 2.2.4 Solution Synthesis of Metal Nanoparticles Using Chemical Reduction Method

Stereo-Controlled Liquid Phase Synthesis of Phosphorothioate Oligonucleotides on a Soluble Support.

5'-O-(2-Methoxyisopropyl) (MIP)-protected 2'-deoxynucleosides as chiral P(V)-building blocks, based on the limonene-derived oxathiaphospholane sulfide, were synthesized and used for the assembly of di-, tri-, and tetranucleotide phosphorothioates on a tetrapodal pentaerythritol-derived soluble support. The synthesis cycle consisted of two reactions and two precipitations: (1) the coupling under basic conditions, followed by neutralization and precipitation and (2) an acid catalyzed 5'-O-deacetalization, followed by neutralization and precipitation. The simple P(V) chemistry together with the facile 5'-O-MIP deprotection proved efficient in the liquid phase oligonucleotide synthesis (LPOS). Ammonolysis released nearly homogeneous Rp or Sp phosphorothioate diastereomers in ca. 80% yield/synthesis cycle.

Toward Scalable Liquid-Phase Synthesis of Sulfide Solid Electrolytes for All-Solid-State Batteries

All-solid-state batteries (ASSBs) are promising to be next-generation battery that provides high energy density and intrinsic safety. Research in the field of ASSBs has so far focused on the development of highly conductive solid electrolytes (SEs). The commercialization of ASSBs requires well-established large-scale manufacturing for sulfide SEs with high ionic conductivity. However, the synthesis for sulfide SEs remains at the laboratory scale with limited scalability owing to their air sensitivity. The liquid-phase synthesis would be an economically viable manufacturing technology for sulfide SEs. Herein, we review a chemical perspective in liquid-phase synthesis that offers high scalability, low cost, and high reaction kinetics. This review provides a guideline for desirable solvent selection based on the solubility and polarity characterized by the donor number and dielectric permittivity of solvents. Additionally, we offer a deeper understanding of the recent works on scalable liquid-phase synthesis using solubilizers and reactant agents. We present an outlook on a universal liquid-phase synthesis of sulfide SEs toward the commercialization of sulfide-based ASSBs.

Electrical study of a novel pyrene boned graphene nanoribbon film and its specific aniline sensing feature

Sensitive, rapid, and recyclable opto-electrically integrated multi-response nanomaterials are needed for public health and safety. Graphene nanoribbons are potential candidates for optoelectronic integrated sensors attributed to their intriguing electrical and optical characteristics. In the research, liquid-phase bottom-up synthesis produced a luminous cove-type graphene nanoribbon (cGNRs-Pyrene) containing alkyl chains and pyrene functional groups at the edge. The FET array devices based on cGNRs-Pyrene films show impressive output and transport properties, with an on/off ratio of up to 1838, caused by the high conductivity of graphene nanoribbons. Surprisingly, cGNRs-Pyrene exhibits excellent fluorescence quenching sensing properties for aniline with a detection limit of 0.3 nM·L−1, and the fluorescence quenching efficiency of cGNRs-Pyrene can as high as 62% with the addition of 1 equivalent of aniline. More interestingly, after adding acid to the cGNRs-Pyrene-aniline solution, the fluorescence intensity of cGNRs-Pyrene can be restored to the initial value, showing the excellent recyclability of cGNRs-Pyrene. This study demonstrates that fluorescent cGNRs-Pyrene has the potential to realize a composite dual-channel high-sensitivity opto-electrically integrated sensor, building a new generation of highly sensitive multi-channel responsive sensors with both electrical and optical sensing.

Synthesis of Asymmetrical CsPbBr3/TiO2 Nanocrystals with Enhanced Stability and Photocatalytic Properties

Practical applications of CsPbX3 nanocrystals (NCs) are limited by their poor stability. The formation of a heterojunction between CsPbX3 NCs and oxides is an effective means to protect perovskite from polar solvents and other external factors. Significantly improving the stability and photocatalytic properties of the core/shell perovskite is very important for its application in photoelectric and photocatalytic technology. Here, we report the synthesis of asymmetrical CsPbBr3/TiO2 core–shell heterostructure NCs at the single-particle level by hot-injection liquid-phase synthesis and sol–gel method, where each CsPbBr3 NCs is partially covered by titanium dioxide. We tested not only the optical properties of the material but also the electrochemical impedance and photocurrent density of the material in sodium sulfate solution. It is shown that the type II arrangement is generated at the heterogeneous interface, which greatly facilitates the separation of electron–hole pairs and increases the carrier transport efficiency. Compared with CsPbBr3 NCs, CsPbBr3/TiO2 has higher photocatalytic efficiency. More crucially, due to the protection of the titanium dioxide shell, the product has higher long-term stability in humid air compared with bare CsPbBr3 NCs. The asymmetrical core–shell heterostructure prepared in this study not only improves the stability of CsPbX3 NCs but also provides some ideas for optoelectronic device applications and TiO2-based photocatalysts.

Halogen Doping Mechanism and Interface Strengthening in the Na3SbS4 Electrolyte via Solid-State Synthesis.

Good-performing sodium solid electrolytes (SSEs) are essential for constructing all-solid-state sodium-ion batteries operating at ambient temperature. Sulfide solid electrolyte, Na3SbS4 (NBS), an excellent SSE with good chemical stability in humid air, can be synthesized with low-cost processing. However, Na3SbS4-based electrolytes with liquid-phase synthesis exhibit conductivities below milli-Siemens per centimeter. Thus, a series of halogen-doped samples formulated as Na3-xSbS4-xMx (0 ≤ x ≤ 0.3, M = Cl, Br, and I) were experimentally prepared in this study using the solid-state method to improve the battery performance. X-ray diffraction with refinement analysis and Raman spectroscopy were employed to understand deeply the connection between the crystal structure and conductivity of Na+ ions. In addition, symmetric sodium batteries with Na2.85SbS3.85Br0.15 were tested at room temperature, and pristine Na3SbS4 was used as the control group. The result showed that the symmetric sodium battery assembled with the Na2.85SbS3.85Br0.15 electrolyte can stably cycle for longer than 100 h at a current density of 0.1 mA/cm2. This research provides a method to manufacture novel SSEs by elaborating the effect of halogen doping in NBS.

Development of the efficient preparation method for thermoresponsive elastin-like peptides using liquid-phase synthesis combined with fragment condensation strategy.

Elastin-like peptides (ELPs) are synthetic peptides that mimic the characteristic hydrophobic amino acid repeat sequences of elastin and exhibit temperature-dependent reversible self-assembly properties. ELPs are expected to be used as temperature-responsive biomolecular materials across diverse industrial and research fields, and there is a requirement for a straightforward method to mass-produce them. Previously, we demonstrated that phenylalanine-containing ELP analogs, namely, (FPGVG)n , can undergo coacervation with short chains (n = 5). The Fmoc solid-phase peptide synthesis method is one strategy used to synthesize these short ELPs. However, owing to its low reaction efficiency, an efficient method for preparing ELPs is required. In this study, efficient preparation of ELPs was investigated using a liquid-phase synthesis method with a hydrophobic benzyl alcohol support (HBA-tag). Because HBA-tags are highly hydrophobic, they can be easily precipitated by the addition of poor solvents and recovered by filtration. This property allows the method to combine the advantages of the simplicity of solid-phase methods and the high reaction efficiency of liquid-phase methods. By utilizing liquid-phase fragment condensation with HBA-tags, short ELPs were successfully obtained in high yield and purity. Finally, the temperature-dependent response of the ELPs generated through fragment condensation was assessed using turbidity measurements, which revealed a reversible phase transition. Consequently, the ELPs exhibited a reversible phase transition, indicating successful synthesis of ELPs via fragment preparation with tags. These findings provide evidence of the potential for mass production of ELPs using this approach.

Structure and Phase Composition of WNb Alloy Formed by the Impact of Compression Plasma Flows.

The results of a tungsten-niobium alloy synthesis by the impact of pulsed compression plasma flows are presented. Tungsten plates with a 2 μm thin niobium coating were treated with dense compression plasma flows generated by a quasi-stationary plasma accelerator. The plasma flow with an absorbed energy density of 35-70 J/cm2 and pulse duration of 100 μs melted the niobium coating and a part of the tungsten substrate, which caused liquid-phase mixing and WNb alloy synthesis. Simulation of the temperature distribution in the top layer of the tungsten after the plasma treatment proved the formation of the melted state. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to determine the structure and phase composition. The thickness of the WNb alloy was 10-20 μm and a W(Nb) bcc solid solution was found.

Effect of Gas-Phase Passivation Technology on Spontaneous Combustion Characteristic Stage and Reaction Kinetics of FeS During Particle Size Fragmentation

ABSTRACT To investigate the mechanism of inhibition of spontaneous combustion of reactive FeS by gas-phase passivation, this paper used liquid-phase synthesis to prepare reactive FeS which were divided into five particle size ranges by crushing and grinding and then passivated those by low-oxygen gas. This paper analyzed the effect of gas-phase passivation on the characteristic parameters of the characteristic stages of crushed FeS from the perspective of thermodynamics, and used the KAS and FWO methods to calculate the apparent activation energy of the different characteristic stages of the FeS oxidation heating process. Inhibition mechanism of FeS spontaneous combustion reaction kinetics during particle size fragmentation by gas-phase passivation was revealed. The results indicate that in the spontaneous combustion stage at room temperature (RT), the exothermic heat of passivated FeS was significantly reduced to below 5 J/g, and the apparent activation energy rose up to 116 kJ/mol, which was significantly increased by about 50% compared to the activated FeS. The essence of gas-phase passivation is that the low oxygen concentration gas reacts with FeS to produce a passivation protective film, blocking the reaction and pushing the oxidation process backwards as a whole. In the weight gain stage of oxygen absorption, the weight gain of passivation FeS is reduced to less than 2.2%, and the heat release is reduced to 2.8J/g. The particle size of the passivated FeS decreased, and the apparent activation energy increased by 20 kJ/mol in the decomposition and combustion stage. With the decrease of FeS particle size, the gas-phase passivation is more effective and the inhibition effect of spontaneous combustion of FeS is more obvious.

Review on Preparation of Polystyrene Microspheres

The traditional preparation methods of polystyrene microspheres are emulsion polymerization and suspension polymerization. The diameter of the microspheres prepared by the former is generally less than 0.5 m, and the diameter of the microspheres prepared by the latter is about several hundred microns and is difficult to control. With the continuous development of science and technology, scientists have found multiple methods to prepare micron-sized monodisperse polymer microspheres in recent years. Such as soap-free or low-soap emulsion method, dispersion polymerization method, liquid-phase synthesis method. The four preparation methods of dispersion polymerization, emulsion polymerization, liquid-phase synthesis, suspension polymerization and their respective advantages and disadvantages are discussed in detail, and the prospect of synthetic application is prospected.