Towards a new avenue for rapid synthesis of electrocatalytic electrodes via laser-induced hydrothermal reaction for water splitting

Electrochemical production of hydrogen from water requires the development ofelectrocatalysts that are active,stable,and low-cost for water splitting.To address these challenges,researchers are increasingly exploring binder-free electrocatalytic integratedelectrodes (IEs) as an alternative to conventional powder-based electrode preparation methods,for the former is highly desirable to improve the catalytic activity and long-term stability for large-scale applications of electrocatalysts.Herein,we demonstrate a laser-inducedhydrothermal reaction (LIHR) technique to grow NiMoO4nanosheets on nickel foam,which is then calcined under H2/Ar mixed gases to prepare the IE IE-NiMo-LR.This electrode exhibits superior hydrogen evolution reaction performance,requiring overpotentials of 59,116 and143 mV to achieve current densities of 100,500 and 1000 mA·cm-2.During the 350 h chronopotentiometry test at current densities of 100 and 500 m A·cm-2,the overpotentialremains essentially unchanged.In addition,NiFe-layered double hydroxide grown on Ni foam is also fabricated with the same LIHR method and coupled with IE-NiMo-IR to achieve water splitting.This combination exhibits excellent durability under industrial current density.The energy consumption and production efficiency of the LIHR method are systematicallycompared with the conventional hydrothermal method.The LIHR method significantly improves the production rate by over 19 times,while consuming only 27.78%of the total energy required by conventional hydrothermal methods to achieve the same production.

Navigating the pathways:TAR-DNA-binding-protein-43 aggregation,axonal transport,and local synthesis in amyotrophic lateral sclerosis pathology

Neurons are highly polarized cells with axons reaching over a meter long in adult humans.To survive and maintain their proper function,neurons depend on specific mechanisms that regulate spatiotemporal signaling and metabolic events,which need to be carried out at the right place,time,and intensity.Such mechanisms include axonal transport,local synthesis,and liquid-liquid phase separations.Alterations and malfunctions in these processes are correlated to neurodegenerative diseases such as amyotrophic lateral sclerosis(ALS).

Facile synthesis of C2 or C3-(cycloheptatrienyl)-substituted indoles

Cycloheptatriene is a privileged structural motif present in many bioactive compounds,pharmaceutical agents and natural products,especially in a large number of core structures of sesquiterpenoids.Herein,a mild and efficient synthetic approach was reported for access of a series of C2 or C3-(cycloheptatrienyl)-substituted indoles.A wide range of functional groups can be well tolerated in this transformation,especially including hydroxyl,halo,carboxylic acid and its derivative groups.Based on these results,a rational mechanism via electrophilic substitution of indoles with tropylium tetrafluoroborate is proposed.

Synthesis of lutetium hydrides at high pressures

High-pressure synthesis of lutetium hydrides from molecular hydrogen(H_(2))and lutetium(Lu)is systematically investigated using synchrotron X-ray diffraction,Raman spectroscopy,and visual observations.We demonstrate that the reaction pathway between H_(2)and Lu invariably follows the sequence Lu→LuH_(2)→LuH_(3)and exhibits a notable time dependence.A comprehensive diagram representing the formation and synthesis of lutetium hydrides as a function of pressure and time is constructed.Our findings indicate that the synthesis can be accelerated by elevated temperature and decelerated by increased pressure.Notably,two critical pressure thresholds at ambient temperature are identified:the synthesis of LuH_(2)from Lu commences at a minimum pressure of~3 GPa,while~28 GPa is the minimum pressure at which LuH_(2)fails to transform into LuH_(3)within a time scale of months.This underscores the significant impact of temporal factors on synthesis,with the reaction completion time increasing sub-linearly with rising pressure.Furthermore,the cubic phase of LuH_(3)can be obtained exclusively through compressing the trigonal LuH_(3)phase at~11.5 GPa.We also demonstrate that the bandgap of LuH_(3)slowly closes under pressure and is noticeably lower than that of LuH_(2).

The composition of magmatic-hydrothermal fluids and their related metal mineralization

Magmatic hydrothermal deposits are important sources of many bulk,precious,and rare metals,and have attracted interest from both academic and industrial communities.However,it is still unclear if the major enrichment of the ore-forming metals occurs in the parental magma source region,during the magma evolution,or after the fluid exsolution.Fluid inclusions trapped in hydrothermal minerals crystallized in the early,high-temperature stage before metal precipitation record information close to that of the initially exsolved magmatic fluids,which are helpful in revealing whether the metals have been already significantly enriched prior to the hydrothermal stage.In this study,available compositional data of such early-stage fluid inclusions from magmatic hydrothermal systems globally have been compiled.The results indicate that the concentrations of Cu,Sn,and W respectively from the Cu-,Sn-,and W-mineralized fluids are significantly higher than the hydrothermal systems that do not produce ores with the corresponding metals.This suggests that Cu,Sn,and W could have already been enriched in the magma source and/or magma evolution stage.The Mo concentrations show no difference between Mo-mineralized and Mobarren fluid systems,indicating no significant pre-enrichment in the source region or during the magma evolution.This also implies that an efficient collection of Mo from a large volume of magmas is required to account for the formation of a large Mo deposit.Almost all the hydrothermal fluids contain high concentrations of Fe and Zn-Pb,but only a few of them eventually form Fe or Zn-Pb deposits,reflecting an important role of the hydrothermal evolution process on the selective metal mineralization.The above results indicate that different metals are enriched in different stages of a magmatic hydrothermal system,and that the major roles played in the formation of a deposit vary with the metal types.In addition to the metal concentrations in the orerelated magmas and fluids,other factors(including but not limited to the intrusion shapes,emplacement depths,structural pathways,and wallrock properties)are also critical in determining the fertility and mineralization diversity of a magmatic hydrothermal system.

Hydrothermal synthesis, characterization and optical properties of La_2Sn_2O_7:Eu^(3+) micro-octahedra

Pyrochlore structure La2Sn2O7：Eu3＋ microcrystals with uniform octahedron shape were successfully synthesized via a hydrothermal route at 180 °C for 36 h. The crystal structure, particle size, morphologies, and optical properties of the as-synthesized products were investigated by XRD, TEM, SEM, EDS, FT-IR, Raman spectroscopy and PL. The effects of pH of precursor solution, precursor concentration, reaction temperature, and time were investigated. The results reveal that pH of the precursor solution not only plays an important role in determining the phase of the as-synthesized products, but also has a significant influence on the morphologies of the samples. High-quality and uniform octahedrons with an average size of about 700 nm could be easily obtained at the pH value of 12. The possible formation mechanism of octahedral-like La2Sn2O7：Eu3＋ microcrystals was briefly proposed. The photoluminescence spectra show that La2Sn2O7：Eu3＋ micro-octahedra display stronger emission in the range of 582-592 nm compared with the samples with other shapes.

Hydrothermal synthesis of silver nanoparticles in Arabic gum aqueous solutions

Finely divided silver nanoparticles were synthesized via the hydrothermal method. Arabic gum （AG） was used as both the reductant and steric stabilizer without any other surfactant. By adjusting the reaction temperature, mass ratio of AG to AgNO3, and reaction time, silver nanoparticles with different morphological characteristics could be obtained. The products were characterized by UV-Vis, FTIR, TEM, SEM, and XRD measurements. It was found that temperature and AG played an important role in the synthesis of mono-disperse silver nanoparticles. Well dispersed and quasispherical silver nanoparticles were obtained under the optimal synthesis conditions of 10 mmol/L AgNO3, m（AG）/m（AgN03）= l：1, 160 ℃ and 3 h.

Facile H2O2 Hydrothermal Synthesis of Bimodal Mesoporous Silica MCM-48 Spheres

The ordered bimodal mesoporous silica MCM-48 spheres were facile synthesized by mild- temperature post-synthesis H2O2 hydrothermal treatment of as-synthesized MCM-48. The results showed that H2O2 is indispensable for simultaneously removing organic templates and forming ordered bimodal mesoporous silica MCM-48 spheres. The bimodal mesoporous MCM-48 was characterized by X-ray diffraction, transmission electron micrographs, FT-IR, and N2 adsorption-desorption, and a possible mechanism was proposed for the formation of bimodal mesoporous MCM-48.

One-step hydrothermal synthesis of Cu-SAPO-34/cordierite and its catalytic performance on NO_x removal from diesel vehicles

Cu-SAPO-34/cordierite catalysts were prepared via one-step hydrothermal synthesis method and their performances to remove NO x from the diesel vehicle exhaust were evaluated. The morphology, structure, Cu content and valence state were characterized by SEM, XRD, ICP and XPS, respectively. The experimental results show the active component Cu of the catalysts via in situ synthesis could significantly improve the selective catalytic reduction （SCR） activities of NOx and the optimal Cu content is in the range of 0.30%-0.40%（mass fraction）. No N 2 O is detected by gas chromatograph （GC） during the evaluation process, which implies that NOx is almost entirely converted to N2 over Cu-SAPO-34/cordierite catalyst. The conversion rate of NOx to N2 by NH3 over catalyst could almost be up to 100%in the temperature range of 300-670 ℃with a space velocity of 12000 h-1 and it is still more than 60% at 300-620 ℃ under 36000 h-1. The catalysts also show the good hydrothermal and chemical stability at the atmosphere with H 2 O.

Facile hydrothermal synthesis of TiO_2-Ca P nano-films on Ti6Al4V alloy

Ti6Al4V alloy was subjected to hydrothermal treatment in the concentrated Ca3(PO4)2, Ca HPO4 and Ca(H2PO4)2 solutions for bioactive surface modification. The treated samples are covered by films composed of nano-particles with the size of 60-240 nm. Such film can also be grown on the strut surface of a Ti6Al4 V scaffold prepared by electron beam melting(EBM) technology. XPS analysis indicates that Ti element on the surface presents as TiO2, and Ca and P elements are in the form of calcium phosphate. XRD and Raman analyses show that the surface layer is composed of anatase TiO2 and hydroxyapatite. Potentiodynamic polarization test in a Ca-free Hank's balanced solution demonstrates that the treated sample has markedly improved corrosion resistance compared with the polished sample. The present work provides a bioactive surface modification method that is easily-operated, low-temperature, less corrosion, and applicable to porous Ti6Al4 V alloy for biomedical applications.

Hydrothermal synthesis of nanosized ZSM-22 and their use in the catalytic conversion of methanol

ZSM‐22 zeolite with different crystal lengths was prepared using a modified hydrothermal method. Rotation speed, Si/Al molar ratio and co‐solvent have important effects on the crystal size of ZSM‐22. The nanosized zeolite samples were characterized by X‐ray diffraction, X‐ray fluorescence, nitrogen adsorption, scanning electron microscopy, temperature‐programmed desorption of am‐monia and solid state nuclear magnetic resonance. The catalytic performance of nanosized ZSM‐22 was tested using the conversion of methanol. Compared to conventional ZSM‐22, the nanosized ZSM‐22 zeolite exhibited superior selectivity to ethylene and aromatics and lower selectivity to propylene. Stability against deactivation was clearly shown by the nanosized ZSM‐22 zeolite. A higher external surface area and smaller particle size make this nanosized ZSM‐22 zeolite attractive for catalytic applications.

Hydrothermal Synthesis and Electrochemical Properties of Amorphous LiMoS2 as a High Capacity Anode Material for Lithium Ion Batteries

The LiMoS： anode material for lithium ion rechargeable batteries were synthesized by a hydrothermal method at 150 ℃. According to our measurements with X-ray diffraction, LiMoS2 was amorphous structure. Electrochemical measurements results showed that LiMoS2 exhibited large lithium storage capacities.

Hydrothermal synthesis of monodisperse Zn_(x)Cd_(1-x)S spheres and their photocatalytic properties

Monodisperse ZnxCd1-xS spheres were successfully fabricated with a high yield by a facile hydrothermal route.The as-prepared samples were characterized by X-ray diffractometry,scanning electron microscopy and UV-vis diffusion reflectance spectroscopy.The results indicate that all the prepared samples have the same hexagonal wurtzite phase and exhibit good size uniformity and regularity.Degradation of rhodamine-B（RhB） was used to evaluate the photocatalytic activities of ZnxCd1-xS samples.Zn0.4Cd0.6S possessed the best photocatalytic activity and exhibited high stability during the reaction.

Synthesis and Electrochemical Property of Flowerlike LiFePO4 by Poly（ethylene glycol）-assisted Hydrothermal Process

Flowerlike LiFePO4 particles self-assembled by plate-like crystals with about 200 nm thickness were prepared by the poly（ethylene glycol）-assisted hydrothermal synthesis. Poly（ethylene glycol） in the hydrothermal system played an important role in reducing the thickness of the plate-like LiFePO4 crystals as a co-solvent and forming the flower- like structure as a soft template. The flowerlike LiFePO4 exhibits high discharge capacity of 140 mAh/g and shows quite good cycling performance in the lithium-ion batteries. Con- sidering that the conductive carbon in the obtained LiFePO4 is negligible, the excellent cell performance suggests that the flowerlike LiFePO4 is a promising cathode material for the lithium-ion batteries.

Hydrothermal Synthesis of Rhombus-like SmCO3OH Microplates and Its Photoluminescence Property Doped with Eu^3＋

Rhombus-like SmCO3OH microplates with the edge lengths ranging from 5 μm to 10 μm and the thickness about 1.5 μm were synthesized through a simple hydrothermal method using urea as the precipitance. The structure and properties of the rhombus-like SmCO3OH microplates were characterized by X-ray diffraction, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The optical property of the rhombus-like SmCO3OH microplates doped with Eu^3＋ was investigated by photoluminescence. A broad and strong emission band at 677 nm was obtained, which can be contributed to producing light conversion film.

Hydrothermal Synthesis and Crystal Structure of a Zinc Complex:[Zn_(2.5)(phen)(BDC)_2(OH)] (phen = 1,10-Phenanthroline, BDC = Benzene-1,4-dicarboxylic Acid)

A metal-organic coordination polymer [ZnE.s（phen）（BDC）2（OH）]2 （phen = 1,10- phenanthroline, BDC = benzene-1,4-dicarboxylic acid） 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. The complex crystallizes in the triclinic system, space group PI with a = 11.199（2）, b = 11.593（2）, c = 11.865（3）/A, α= 99.330（1）, β = 111.506（1）, γ = 104.804（1）^o, V= 1328.4（5）A^3, Dc= 1.722 g/cm^3, Z = 1, Mr = 1377.82, F（000） = 692,μ（MoKa） = 2.306 mm^-1, S = 1.093, R= 0.0281 and wR = 0.0756 for 4179 observed reflections （I 〉 2σ（/））. The coordination polyhedron around Zn（II） can be described as a tetrahedron, trigonal bipyramid and octahedron. It is worth noting that the crystal structure of 1 is composed of tetranuclear zinc clusters linked by {ZnO6} units.

Hydrothermal synthesis of Y(OH)_3,Y(OH)_3:Eu^(3+) nanotubes and the photoluminescence of Y(OH)_3:Eu^(3+),Y_2O_3:Eu^(3+)

The phase and morphology transformation during the hydrothermal treating process of Y2O3 was evaluated with X-ray difference (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size and specific surface area determination. The results showed that the cubic Y2O3 did not transfer into hexagonal Y(OH)3 in pure water. Therefore, pure hexagonal Y(OH)3 with nanotube and microrod morphologies were obtained by hydrothermal treating Y2O3 at 150 oC for 12 h in 15 ml of 2 mol/L NaOH solution with and without PVA or PEG. It was suggested that the characteristic preferential growth of Y(OH)3 was attributed to the structure anisotropy of hexahedron Y(OH)3. The addition of PVA or PEG could promote the forming process of nanotubes by selective adsorption on different crystal planes, which altered the growth rate along different directions and resulted in the diffusion limit of constructing ions in the center top of rods. Finally, Y(OH)3:Eu and Y2O3:Eu nanotubes were also synthesized by using this method, and their photoluminescence properties were evaluated.

Synthesis of LiFePO_4 /C as cathode material by a novel optimized hydrothermal method

Olivine LiFePO 4 , as a cathode material for lithium ion batteries, was prepared by a novel optimized hydrothermal method; afterwards, the product mixed with glucose was two-step （350℃ and 700℃） calcinated under high-purity N 2 atmosphere to obtain the LiFePO 4 /C composite. The study on the hydrothermal preparation method, which focused on the influences of molar ratios, initial pH value, reaction temperature, and duration, was made to promote the resultant performances and to investigate the relations between the performances and the reaction conditions. The resultant samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and electrochemical tests, which include charge-discharge, electrochemical impedance spectroscopy, and cyclic voltammetry. The result shows that the optimal hydrothermal condition is to set the Li：Fe：P molar ratio at 3：1：1 and the reaction temperature at 180℃ for 5 h duration with an initial pH value of 7. The optimized sample, with an average particle size of 100 to 300 nm and a discharge capacity of 118.2 mAh·g-1 at 0.1C, exhibits a stable and narrow-gapped charge-discharge platform and small capacity losses after cycles.

Hydrothermal Synthesis,Crystal Structure and Electrochemical Properties of Complex Cu(α-Furacrylic acid)_2(phen)

The title complex （C26H18CuN206, Mr= 517.96） has been synthesized by the reaction of α-furanacrylic acid with 1,10-phenanthroline （phen） in the solvent mixture of water and methanol. Crystal data： monoclinic, space group C2/c with a = 2.2927（4）, b = 1.01248（18）, c = 1.05061（18） nm, β = 111.188（3）°, V= 2.274（7） nm^3, Dc = 1.513 g/cm^3, Z = 4, F（000） = 1060,μ = 1.007mm^-1, R = 0.0320 and ωR = 0.0781. The crystal structural analysis shows that the copper atom is coordinated with four oxygen atoms from two α-furacrylic acids and two nitrogen atoms from 1,10-phenanthroline, giving a distorted octahedral coordination geometry. The result of electrochemical analysis shows that the electron transfer in the electrode reaction is quasi-reversible.

Hydrothermal Synthesis and Characterization of a Novel Supramolecular Network Compound [Co(IN)_2(H_2O)_4](IN=Isonicotinate)

A novel supramolecular compound, [Co(IN)_2(H_2O)_4](1), was synthesized by means of the hydrothermal method and its structure was characterized with elemental analysis, FT-IR spectrum, TGA and X-ray diffraction. Though the unit cell structure of the title compound is only monomeric, all these units as building blocks are assembled into a novel three-dimensional supramolecular network via the widely hydrogen-bonding and π-π stacking interactions.