Room-temperature Solid-state Reaction Research Articles

Green Synthesis, Characterization and Thermal Investigation of Ni(II) and Cu(II) Complexes Constructed by Pyridine-2,6-Dicarboxylic Acid

Two complexes [Ni(pda)(H2pda)]·3H2O (1) and [Cu(pda)(H2pda)] (2) containing pyridine-2,6-dicarboxylic acid (H2pda) were synthesized by room-temperature solid state reaction and characterized by elemental analyses, powder X-ray diffraction (PXRD), single crystal X-ray diffraction and infrared spectroscopy. The powder complexes were confirmed as single phase with their PXRD. The thermal property was studied using simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC) techniques. The complexes were decomposed in several stages and the final products of their thermal decomposition were NiO and CuO, respectively. In order to explore application of the complexes, the nano-NiO and nano-CuO particles were produced by using the powder complexes as precursors at different temperatures. The particles were characterized and observed by PXRD and scanning electron microscope (SEM), and their average diameters of the pyrolysis products at 500 and#176;C were about 12 and 30 nm, respectively.

Facile fabrication of the hybrid of amorphous FePO4·2H2O and GO toward high performance sodium-ion batteries

Iron phosphate (FePO4) with moderate working voltage is an appealing cathode material for room temperature rechargeable sodium-ion batteries (SIBs), while the low electronic conductivity and poor cycle performance remarkably impede its possible energy storage applications. In this work, we report a simple route to fabricate graphene oxide (GO) hybridized amorphous FePO4·2H2O composite for SIBs. By directly mixing FeCl3·6H2O and GO (mass controlled by x wt% of the mass of FeCl3·6H2O) in an agate mortar with pestle, Fe3+ ions could be bound by the oxygen-containing functionalities on the surface of GO nanosheets. After adding NH4H2PO4 powder to the above mixture, a direct room temperature solid state reaction between the GO-confined Fe3+ ions and PO43− polyanions results in an in-situ hybridization of amorphous FePO4·2H2O and GO, i.e. the target electroactive material (denoted as FePO4@GO-x) is attained. In-depth mechanism for the solid state reaction is demonstrated by FTIR and XPS techniques. The optimized hybrid of amorphous FePO4·2H2O and GO (FePO4@GO-15 composite) exhibits the best sodium storage performance. A high reversible charge capacity of 129.0 mAh g−1 is delivered at a current density of 100 mA g−1 for the first cycle, which is around 90% of the theoretical capacity (144 mAh g−1) of FePO4·2H2O. The composite also exhibits outstanding rate performance, superior reversibility, and satisfactory long-lasting cycle stability. When cycled at a high current density (800 mA g−1 at 31 °C), the composite cathode still delivers a charge capacity of 51 mAh g−1 over 1000 cycles, corresponding to 67% of the first charge capacity. The results presented clearly indicate that the hybrid of amorphous FePO4·2H2O and GO is a promising cathode material for SIBs.

Hierarchical BiOCl flowerlike microspheres via a room-temperature solid-state chemical reaction as a new anode for rechargeable magnesium-ion batteries.

Rechargeable magnesium-ion batteries (MIBs) have received much attention in recent years, but their development remains limited due to a lack of anode materials with high capacity and fast diffusion kinetics. Herein, for the first time, hierarchical BiOX (X = Cl, Br, I) flowerlike microspheres composed of interleaved nanosheets are constructed via a simple room-temperature solid-state chemical reaction as the anode for MIBs. Among them, BiOCl flowerlike microspheres deliver good cycling stability (110 mA h g-1 after 100 cycles) and a superior rate capacity (134 mA h g-1 at 500 mA g-1). This is attributed to their unique flowerlike microsphere structure that not only accommodates a volume change to maintain their structural integrity but also shortens the ion-transport path to improve the diffusion rate. Importantly, ex situ tests were carried out to clarify the phase and structure evolution of the BiOCl flowerlike microspheres during cycling. The results show that BiOCl is first transformed to Bi and then alloyed to Mg3Bi2 in the discharging process, and Mg3Bi2 is turned back to Bi in the charging process. Besides, the initial microsphere structure is essentially maintained during the discharging/charging process, indicating the better stability of the structure. The current study demonstrates that the structural design of flowerlike microspheres is an effective strategy to develop promising anode materials for MIBs.

A facile method to synthesize BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) nanopowders for the application on highly conductive proton-conducting electrolytes

BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb), one kind of promising electrolyte materials for proton-conducting solid oxide fuel cells (H+-SOFCs), generally suffers from the poor sinterability, leading to poor electrochemical performances lower than expected. Herein, a facile method, modified room temperature solid-state reaction (M-RTSSR) was proposed for synthesizing highly active BZCYYb nanopowders. Pure perovskite BZCYYb powders can be obtained at a low calcination temperature of 950 °C and a short dwelling time of 3 h. The highly active character allows the sintering temperature of BZCYYb electrolytes decrease from 1550 °C to 1450 °C, thus effectively suppressing the Ba evaporation and promoting the grain growth. The electrical conductivity measured at 700 °C in wet air is 2.6 × 10−2 S cm−1, which mainly benefits from the improvement of grain boundary conductivity. According to the analysis based on space charge layers, the enhanced electrical performance can be ascribed to their lower space charge potential (Δφ (0)) and higher impurity blocking item (ω/dg). Finally, the anode-supported single cell with such BZCYYb electrolytes reaches a peak power density of 0.54 W cm−2 at 700 °C while taking humid H2 (∼3 vol% H2O) as fuels and ambient air as oxidants.

Green Synthesis and Characterization of Zinc Pyridine-2,6-Dicarboxylate Complex and Preparation of Nano-ZnO by Thermal Decomposition

A complex [Zn(Hpda)2]•2H2O of pyridine-2,6-dicarboxylic acid (H2pda) was synthesized by a green chemistry approach, namely, room-temperature solid state reaction. The complex was characterized by elemental analyses, powder X-ray diffraction (PXRD), single crystal X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), and thermogravimetry and differential scanning calorimetry (TG-DSC). The PXRD result confirmed that the unpurified powder complex was single phase. The crystal structure of the complex belonged to monoclinic system with space group P21/c, and the Zn(II) ion was hexacoordinated by four O atoms and two N atoms. The thermal decomposition of the complex was investigated and the nano-ZnO particles were prepared by pyrolysis of the unpurified powder complex as the precursor. The ZnO particle obtained by pyrolysis at 500 °C was characterized by PXRD and scanning electron microscope (SEM), and its average diameter was about 40 nm.

Structure and emission properties of barium calcium aluminates synthesized by room-temperature solid-state reaction approach

The two conventional aluminate precursor preparation methods are liquid-state co-precipitation and mechanical mixture, needing high temperature to fabricate thermionic cathodes for vacuum devices. Herein, we introduce the room temperature solid states (RTSS) approach to fabricate the precursors of barium calcium aluminates (BCA). For this, crystalline hydrates are used to prepare the precursor through mechanical grinding. The resulting product comprises of crystallized α-(Ba,Ca)CO3 solid solution and Al3+-contained amorphous precipitants. After sintering at 1200 °C, the active phases of Ba3CaAl2O7 and Ba3Al2O6 were obtained. The direct current (dc) emission measurements in a close-space diode configuration revealed that the divergent current density (Jdiv) of the test cathode reaches 7.2 A/cm2 at 1130 °CB, which is comparable to that of the co-precipitation liquid phase method. Considering the virtue of an environmentally-friendly and low-temperature preparation approach, the preparation of aluminates using the RTSS technique has great potential for the fabrication of dispenser cathodes for vacuum devices.

Novel bismuth ferrite nanopowder prepared by polyethylene glycol-assisted two-step solid-state reaction: Synthesis and magneto-optical properties

In this study, a bismuth ferrite (BiFeO3) nanopowder was synthesized by combining Bi(NO3)3·5H2O, Fe(NO3)3·9H2O, and NaOH raw materials in the presence of polyethylene glycol (PEG) with varying polymerization degrees (i.e. PEG200, PEG400, PEG600, and PEG10000). The synthesis process was carried out by room-temperature solid-state reaction followed by subsequent secondary solid-state reaction at 550 °C. The results suggested a significant influence of PEG polymerization degree on the morphology and size of the as-synthesized products. The grain size decreased after the introduction of PEG but increased with the polymerization degree. The vibrating-sample magnetometry data revealed PEG400 and PEG600 with obvious room-temperature ferromagnetism properties. In UV–Vis spectroscopy, the absorption edge exhibited a blue shift as the polymerization degree of PEG rose. In sum, BiFeO3 nanopowder possessed room-temperature ferromagnetism, thereby suitable photocatalyst for wastewater treatment and environmental purification with convenient recycling and substantial economic value.

Fe-doped α-MoO3 nanoarrays: Facile solid-state synthesis and excellent xylene-sensing performance

Fe-doped α-MoO3 nanoarrays have been synthesized via a facile two-step solid-state chemical reaction process. The Fe element was effectively doped into the α-MoO3 nanoarrays self-assembled by nanoplates via an initial room-temperature solid-state reaction and a subsequent mesothermal calcination. The gas-sensing properties of Fe-doped α-MoO3 nanoarrays were investigated and the possibility of its application to gas sensors was explored. The result indicated that 0.3 mol% Fe-doped α-MoO3 nanoarrays exhibited a high response value (28.5) towards 100 ppm xylene within 2 s, which is attributed to its more oxygen vacancies and surface ionized oxygen species. Furthermore, the 0.3 mol% Fe-doped α-MoO3 nanoarrays also manifested a good selectivity and long-term stability. Therefore, the Fe-doped MoO3 nanoarrays are a potential candidate for xylene sensor in future sensing applications.

Room temperature solid-state synthesis of mesoporous BiOI nanoflakes for the application of chemiresistive gas sensors

In recent years, the fabrication of mesoporous nanostructures through low-cost synthesis methods and their utilization as potential sensing elements has fascinated remarkable attention in the field of chemiresistive-type of gas sensors. In this regard, a simple room temperature solid-state reaction approach towards bismuth oxyiodide nanoflakes (BiOI NFs) for the application of C2H5OH gas sensors is described herein. The crystal structure, surface morphology, elemental composition, and surface area characteristics of as-synthesized BiOI are studied by X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, Raman/FTIR spectroscopy, X-ray photoelectron spectroscopy, and nitrogen adsorption/desorption isotherms, respectively. Structural, elemental, and morphological investigation supports to tetragonal configuration of solid-state mediated BiOI together with irregular-shaped nanoflakes-type surface morphology. Surface area analysis confirmed that the BiOI NFs are mesoporous in character with a specific surface area of 17.8510 m2/g. Gas sensing results demonstrated that the as-fabricated BiOI NFs sensors are responsive towards C2H5OH @265 °C with good response reproducibility/stability. BiOI NFs sensor exhibit maximum response of 27% towards 1000 ppm C2H5OH @265 °C. The effect of working temperature and various C2H5OH concentrations (10–1000 ppm) on the response performance of BiOI NFs sensor was carried out thoroughly and described. Additionally, a solid-state reaction mechanism and plausible C2H5OH gas sensing mechanism of BiOI NFs is discussed. The proposed low-cost room temperature solid-state reaction method presents a stimulating way for the rapid synthesis of mesoporous nanopowders for the application of chemiresistive-type of gas sensors.

Realization of High Capacity and Cycling Stability in Pb-Free A2 CuBr4 (A=CH3 NH3 /Cs, 2 D/3 D) Perovskite-Based Li-Ion Battery Anodes.

Lead-free hybrid and inorganic perovskites (A2 CuBr4 ; A=CH3 NH3 or Cs, 2 D or3 D) are synthesized by a room-temperature solid-state reaction route and examined as anode materials in Li-ion batteries. A remarkably high reversible capacity of 630 mAh g-1 is realized in the 2 D hybrid perovskite at 100 mA g-1 at the end of 140 cycles. A full cell with this anode is also tested and shows impressive cycling stability. A good reversible capacity of 420 mAh g-1 with excellent stability tested up to 1400 cycles is also obtained for the 3 D perovskites. Pb-free hybrid/inorganic halide perovskites can thus be used as viable anode materials for battery applications.

In-situ solid-state synthesis and regulation of Ag2O/Ag2CO3 heterojunctions with promoted visible-light driven photocatalytic decomposition for organic pollutant

Ag-based photocatalysts have excellent photocatalytic properties, but their photocatalytic degradation performance is limited by the serious photocatalytic corrosion. In order to enhance the stability of photocatalytic degradation of Ag-based photocatalysts, here, the Ag2O/Ag2CO3 heterojunction was in-situ constructed and conveniently regulated by controlling the alkalinity of room temperature solid-state chemical reaction system. The photocatalytic degradation activity of the obtained heterojunction was influenced by the in-situ regulated component and band position of the Ag2O/Ag2CO3 heterojunction. The obtained optimal products AAC-6 displayed remarkable photocatalytic activity and high reusability. The apparent rate constant of AAC-6 is 20 times than that of Ag2CO3, it is also far higher than that of P25. The significantly enhanced photocatalytic performance can be ascribed to the matching energy position between Ag2CO3 and Ag2O, which can facilitate the visible light absorption ability and the efficient separation of photoinduced charges carriers. This study explored an in-situ one-step solid-state strategy to construct Ag2CO3-based heterojunction catalyst with outstanding photocatalytic performance, which may open a new perspective for the preparation of excellent photocatalytic degradation materials by solid-state chemical method.

Facile and efficient room temperature solid state reaction enabled synthesis of antimony nanoparticles embedded within reduced graphene oxide for enhanced sodium-ion storage

Herein, a very simple and cost-effective solid state reaction method is employed to obtain, for the first time, the antimony nanoparticles embedded within reduced graphene oxide matrices (designated as Sb/rGO). By directly grinding antimony chloride and sodium hydroxide together at room temperature in the presence of graphene oxide (GO), Sb4O5Cl2 precursor was quickly obtained, which is evenly incorporated in the graphene oxide matrices. After subsequent chemical reduction by NaBH4, the Sb/rGO composite was successfully synthesized. The as-prepared Sb/rGO composite consists of uniform Sb nanoparticles of sub-20 nm, all of which have been wrapped in and protected by the rGO matrices. The Sb nanoparticles serve as a sufficient sodium ion reservoir while the rGO matrices provide highly efficient pathways for transport of sodium ions and electrons. Moreover, the volume expansion of Sb during sodiation can be buffered in the rGO matrices. As a result, the Sb/rGO composite exhibits excellent electrochemical performance in sodium-ion batteries (SIBs), including an enhanced cycling stability with a highly reversible charge capacity of 455 mA h g−1 after 45 cycles at 100 mA g−1, and a coulombic efficiency exceeding 98% during cycling. The findings in the present work pave the way to not only synthesize the designated promising electrode materials for high performance SIBs, but also thoroughly understand the solid-state reaction.

Room Temperature Solid State Synthesis, Characterization, and Application of a Zinc Complex with Pyromellitic Acid

The complex [Zn2(btca)(H2O)4] was synthesized with 1,2,4,5-benzenetetracarboxylic acid (H4btca) and zinc acetate as materials via a room-temperature solid state reaction. The composition and structure of the complex were characterized by elemental analyses (EA), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and thermogravimetric (TG) analysis. The index results of X-ray powder diffraction data showed that the crystal structure of the complex belonged to monoclinic system with cell parameters a = 9.882 Å, b = 21.311 Å, c = 15.746 Å, and β = 100.69°. In order to expand the application of the complex, the nanometer zinc oxide was prepared by using the complex as a precursor, and the effect of the thermal decomposition temperature on the preparation of the nanometer zinc oxide was studied. The results showed that the grain size of zinc oxide gradually grew with the increase of the pyrolysis temperature, the obtained nanometer zinc oxide was spherical, and the diameter of the particles was about 25 nm.

Room-temperature solid-state synthesis and fluorescence performance of 8-hydroxyquinoline-based nanomaterial complexes with different morphology

Three main-chain 8-hydroxyquinoline-based metallocomplexes (aluminium(Ⅲ) tri-(8-hydroxyquinoline) (AlQ3), cadmium (Ⅱ) bis-(8-hydroxyquinoline) monohydrate (CdQ2·H2O), and magnesium(Ⅱ) bis-(8-hydroxyquinoline) tetrahydrate (MgQ2·4H2O)) nanomaterials were prepared by room-temperature solid-state reaction technique. The results of X-ray diffraction (XRD), elemental analyses (EA), fourier transform infrared (FTIR) spectroscopy and thermogravimetric/differential scanning calorimetry (TG/DSC) analysis demonstrated that the chemical composition of the products were AlQ3, CdQ2·H2O, and MgQ2·4H2O, respectively. The field emission scanning electron microscopy (FESEM) images and the transmission electron microscopy (TEM) images showed the morphology of AlQ3 nanoshuttles, CdQ2·H2O nanorods, and MgQ2·4H2O nanosheets, respectively. The UV–vis absorption spectra indicated that they existed charge transfer from the metal to the ligand (MLCT bands). The photoluminescence (PL) spectra revealed that three products displayed efficient and intense photoluminescence in yellow-green, deep-green and blue-green emissions region in the state of solid powder. PL intensity was weaker at different degree in chloroform, dimethylformamide, acetone and acetonitrile solutions, which attribute to solvate effect. The fluorescence quantum yields indicated that this metal complex materials can possibly act as functional composites to be used in optoelectronic devices, such as organic light-emitting diodes and fluorescent sensor.

Synthesis and characterization of nanometric gadolinia powders by room temperature solid-state displacement reaction and low temperature calcination

Nanometric-sized gadolinia (Gd2O3) powders were obtained by applying solid-state displacement reaction at room temperature and low temperature calcination. The XRD analysis revealed that the room temperature product was gadolinium hydroxide, Gd(OH)3. In order to induce crystallization of Gd2O3, the subsequent calcination at 600∼1200°C of the room temperature reaction products was studied. Calculation of average crystallite size (D) as well as separation of the effect of crystallite size and strain of nanocrystals was performed on the basic of Williamson-Hall plots. The morphologies of powders calcined at different temperatures were followed by scanning electron microscopy. The pure cubic Gd2O3 phase was made at 600°C which converted to monoclinic Gd2O3 phase between 1400° and 1600°C. High-density (96% of theoretical density) ceramic pellet free of any additives was obtained after pressureless sintering at 1600°C for 4h in air, using calcined powder at 600°C.

Preparation and characterization of nanoscale LiFePO4 cathode materials by a two-step solid-state reaction method

In order to obtain high-performance nanoscale LiFePO4 cathode materials for lithium-ion batteries, CH3COOLi·2H2O, FeC2O4·2H2O, and NH4H2PO4 were used as raw materials to prepare the precursors of LiFePO4 by room-temperature solid-state reaction method firstly; then, LiFePO4 cathode materials were synthesized by high heating solid-state reaction method. The influence of temperature on the crystal structure, microstructure, and electrochemical properties were studied by thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and charge–discharge performance test. It was indicated that the olivine-phase LiFePO4 not only presented nano-sized particles in the range of 40–80 nm, but also showed excellent initial discharge specific capacity of about 155 mAh/g at 0.2 C at a sintering temperature of 700 °C and possessed good cycle performance. This preparation method without any solvent and carbon source addition could realize industrialized production of single-phase nano-LiFePO4.

Solid-state-reaction synthesis of cotton-like CoB alloy at room temperature as a catalyst for hydrogen generation

A novel room-temperature solid-state reaction is developed to synthesize cotton-like CoB alloy (CoBSSR) catalysts with a large specific surface area of 222.4m2g−1. In the hydrolysis of ammonia borane catalyzed by the CoBSSR, the rate of hydrogen generation can reach 68.7mLmin−1 with a turnover frequency (TOF) value of ca. 6.9Lhydrogenmin−1gcatalyst−1 at 25°C. The TOF value is about 2 times as large as that of CoB alloy prepared by a regular solid-state reaction, which is also much higher than those of the CoB catalysts recently reported in the literature. The activation energy of the hydrolysis of ammonia borane catalyzed by the CoBSSR is as low as 22.78kJmol−1, hinting that the CoBSSR possesses high catalytic activity, which may be attributed to the large specific surface area and the abundant porous structure. The high catalytic performance, good recoverability and low cost of the CoBSSR enable it to be a promissing catalyst condidate in the hydrolysis of ammonia borane for hydrogen production in commercial application.

Synthesis of Nano-Phosphor By Water Assisted Room Temperature Solid State Reaction (WASSR) Method

A solid-state reaction method has been usually used as a basis synthesis processing technique to obtain the ceramic materials, including phosphor materials, because of its very simple and easy. However, ceramic materials are generally synthesized at high temperature when the solid state reaction method used as synthesis method. Because ionic-diffusion in ionic crystal is very slow at room temperature, high temperature is essential for solid state reaction. The high temperature synthesis leads to increase in the processing cost and irregular particle morphology of the obtained powder. In contrast, we have proposed the two novel solid phase synthesis technique to synthesize the ceramic materials at low temperature below 100 °C without after any chemical or physical treatment. We refer to these synthesis techniques as water assisted room temperature solid state reaction (WASSR) method and solid hydratethermal reaction (SHR) method.1-3 We successfully synthesized the functional ceramic materials including phosphors. Furthermore, we demonstrated that the reaction mechanism of novel low temperature synthesis methods is different from the conventional solid state reaction and solution reaction. In this study, we present the practicability of our original novel solid state reaction methods on an industrial application in the ceramic oxide materials synthesis processing. References K. Toda, M. Sato, K. Uematsu, and T. Ishigaki, Japanese Unexamined Patent Application Publication No. 2011-16670 (2009).S.W. Kim, T. Kaneko, K. Toda, K. Uematsu, M. Sato, J. Koide, M. Toda, and Y. Kudo, IDW'2014, PH1-3 (2014).T. Kaneko, S.W. Kim, A. Toda, K. Uematsu, T. Ishigaki, K. Toda, M. Sato, J. Koide, M. Toda, Y. Kudo, T. Masaki, and D.H. Yoon, Sci. Adv. Mater., (2015) in press. doi:10.1166/sam.2015.2364.

Ag3PO4 Microcrystals Synthesized by Room-Temperature Solid State Reaction: Enhanced Photocatalytic Activity and Photoelectronchemistry Performance**Supported by the Beijing Higher Education Young Elite Teacher Project under Grant No YETP1297, the Fundamental Research Funds for the Central Universities under Grant No 2014MDLXYZY05, the Undergraduate Innovative Test Program of China under Grant Nos GCCX2015110009 and BEIJ2015110024, and the National Natural Science Foundation of China

Ag3PO4 microcrystals with highly enhanced visible light photocatalytic activity are prepared by a facile and simple solid state reaction at room temperature. The composition, morphology and optical properties of the as-prepared Ag3PO4 microcrystals are characterized by x-ray diffraction, scanning electron microscopy and UV-vis diffuse reflectance spectra. The photocatalytic properties of Ag3PO4 are investigated by the degradation of both methylene blue and methyl orange dyes under visible light irradiation. The as-prepared Ag3PO4 microcrystals possess high photocatalytic oxygen production with the rate of 673 μmolh−1 g−1. Moreover, the as-prepared Ag3PO4 microcrystals show an enhanced photoelectrochemistry performance under irradiation of visible light.

Uniform octahedral-shaped Y2O3:Eu3+ submicron single crystals: Solid-state synthesis, formation mechanism and photoluminescence property

For the first time, uniform octahedral-shaped Y2O3:Eu3+ submicron single crystals with photoluminescence (PL) superior to the as-prepared aggregated spherical counterparts were prepared via a room-temperature solid-state metathesis reaction and subsequent calcination of the as-milled mixtures containing an in situ formed salt as by-product. Their formation mechanism is also discussed based on preferential growth and self-assembling of nanocrystals in the presence of the salt. In summary, the approach promises a great potential in the large scale preparation of octahedral Y2O3:Eu3+ submicron phosphors due to its solvent-free, addictive-free, high-yielding and eco-friendly characteristics.