Highly safe and ionothermal synthesis of Ti3C2 MXene with expanded interlayer spacing for enhanced lithium storage

MXene is a rising star of two-dimensional(2D)materials for energy relative applications,however,the traditional synthesis of MXene etched by hazard HF acid or LiF+HCl mixed solution is highly dangerous with the risk of splashing or pouring liquid solutions.In this work,we developed a water-free ionothermal synthesis of 2D Ti3C2 MXene via etching pristine Ti3AlC2 MAX in low-cost choline chloride and oxalic acid based deep eutectic solvents(DES)with the presence of NH4F,thus it was highly safe and convenient to operate solid precursor and product materials at room temperature.Benefited from the low vapor pressure and solvating properties of DES,the prepared Ti3C2(denoted as DES-Ti3C2)possessed a high purity up to 98% compared with 95% for HF etched Ti3C2(denoted as HF-Ti3C2).Notably,an expanded interlayer spacing of 1.35 nm could be achieved due to the intercalation of choline cations in DES-Ti3C2,larger than that of HF-Ti3C2(0.98 nm).As a result,the DES-Ti3C2 anodes exhibited enhanced lithium storage performance,such as high reversible capacity of 208 m Ah g-1at 0.5 A g-1,and long cycle life over 400 times,outperforming most reported pure MXene anodes.The ionothermal synthesis of MXene developed here may pave a new way to safely prepare other MXene for various energy relating applications.

Ionothermal Synthesis, Crystal Structure and Antibacterial Activities of a New 3d-4f Hetero-metallic Compound Containing Two Kinds of Ligands

A new 3d-4f（CuⅡ-CeⅢ） hetero-metallic compound containing two kinds of ligands, namely [CuⅡ（H2pdc）（phen）（H2O）]（HⅢ3O）2[CeⅢ（pdc）3][CuⅡ（phen）Ce（pdc）3]（1, H2 pdc = pyridine-2,6-dicarboxylic acid, phen = 1,10-phenanthroline）, has been synthesized by an ionothermal method using the ionic liquid 3-butyl-1-methylimidazolium bromide（[Bmim]Br） as solvent, and characterized by elemental analysis, energy-dispersive X-ray spectroscopy（EDS）, IR, XPS and single-crystal X-ray diffraction. The structure reveals that 1 belongs to the triclinic system, space group P1 with a = 12.044（7）, b = 14.841（8）, c = 22.305（13） A, α = 85.802（12）, β = 85.471（12）, γ = 89.174（11）°, Z = 2, V = 3964（4） A3, Dc = 1.804 g·cm-3, F（000） = 2140, μ = 1.757 mm-1, the final R = 0.0734, wR = 0.1094 and S = 1.013. The compound can be viewed as a two-dimensional layered structure composed by 3d-4f hetero-nuclear anions [Cu（phen）Ce（pdc）3]-, coordination cations [Cu（H2pdc）（phen）（H2O）]2＋, coordination anions [Ce（pdc）3]3- and protonated water molecules via hydrogen bonding interactions and π-π stacking. Moreover, the antimicrobial activities of 1 have been also investigated. The results indicated that its inhibitory activity is slightly higher than that of penicillin against Candida albicans.

Ionothermal Synthesis,Structure and Luminescent Properties of a New 2-D Bismuth(Ⅲ) Coordination Polymer with(6,5)-Connected Topological Sheet

A new 2-D Bi（3＋） coordination polymer {Bi4（μ3-O）2（μ4-O）2（C7H3NO4）2}n（1,C7H3NO4 = pyridine-2,6-dicarboxylate） containing（6,5）-connected topological sheet with the Schl？fli symbol of（4~4·6~3·8~4·12~4）（4~5·6~4·8） has been synthesized by an ionothermal method using the ionic liquid 1-ethyl-3-methylimidazolium bromide（[Emim]Br） as solvent,and characterized by C,H and N elemental analysis,energy-dispersive X-ray spectroscopy（EDS）,infrared spectrum（IR spectrum） and single-crystal X-ray diffraction.The results indicate that 1 belongs to the monoclinic system,space group P21/n with a = 13.766（7）,b = 4.142（2）,c = 16.439（8） ？,β = 99.099（9）°,Z = 2,V = 925.6（8） ？~3,Dc = 4.414 g·cm^（-3）,F（000） = 1064,μ = 37.985 mm-1,the final R = 0.0326,wR = 0.0727 and S = 1.022.The molecular structural units [Bi4（μ3-O）2（μ4-O）2（C7H3NO4）2] are connected to each other via bridging O atoms,extending into an interesting 2-D layered structure.These resulting layers are further assembled by weak C-H…O hydrogen bonds into a 3-D supramolecular architecture.Moreover,its thermal stability and the luminescent properties have been also studied.

Ionothermal Synthesis and Characterization of a Threedimensional Anionic Zinc-5-sulfoisophthalate Framework Charge-balanced with the 1-Ethyl-3-methylimidazolium

The ionothermal reaction of Zn（NO3）2·6H2O with 5-sulfoisophthalic acid monosodium salt（NaH2SIP） and 1,2,4-triazole in 1-ethyl-3-methylimidazolium tetrafluoroborate（EMIM-BF4） ionic liquid has afforded the compound {（EMIM）[Zn（SIP）]}n（1）.The Zn（Ⅱ） ions are linked by the carboxylate groups of SIP^3- ligands to give a two-dimensional layered structure featuring the centrosymmetric dinuclear Zn2（μ2-COO）2 units.The adjacent two-dimensional layers are further linked by the Zn-0 bonds between the Zn（Ⅱ） ions and the sulfonate O atoms to generate a three-dimensional anionic[Zn（SIP）]n^n- framework featuring one-dimensional open channels propagating along the a axis.The imidazolium cations[EMIM]^＋ derived from ionic liquid act as extraframework charge-balancing species for the anionic[Zn（SIP）]n^n- framework and occupy the void space of the one-dimensional open channels.The rich ionic environments of the ionic liquid may be particularly helpful in the formation of the ionic compound 1.The roles of the ionic liquid in ionothermal synthesis and crystallization of the compound are briefly discussed.Furthermore,compound 1 displays a photoluminescent emission at 490 nm upon excitation at 406 nm.

In situ Ionothermal Synthesis and Characterization of a Novel Cuprous Halide Complex

A new compound [mpba][Cu_2Br_3]（1, mpba = 4-（N-methylpyridin-4-yl）benzoic acid） has been ionothermally synthesized and characterized by single-crystal X-ray diffraction analysis, infrared spectrum, elemental analyses, fluorescence spectrum, and thermogravimetric analysis. In compound 1, the [mpba]＋ cation is a new organic template, which is obtained firstly in this work by in situ alkylation reaction of N-heterocycles 4-（pyridin-4-yl）benzoic acid with [Emim]Br（Emim = 1-ethyl-3-methyl imidazolium）. Hirshfeld surface analysis shows that weak interactions between the [mpba]＋ cations and 1D inorganic [Cu_2Br_3]~– are mainly C–H···Br hydrogen bonds. In addition, a pairwise O–H···O interaction is observed between the adjacent [mpba]＋cations. These different types of weak interactions make compound 1 stable up to 300 ℃. Fluorescence spectrum investigation shows 1 has a strong yellow emission at 555 nm. Theoretical calculation not only demonstrates compound 1 is a wild band semiconductor with a 3.3 e V band gap but also elucidates the fluorescence emission derives from the p-π＊ transition of electrons from [Cu_2Br_3]~– to [mpba]~＋.

Ionothermal Synthesis and Fluorescence Property of a Complex Constructed by Seven Nuclear(CH_3COO)_2Co_7(OH)_2] Clusters and 4,4＇-Oxybisbenzoic Acid Ligand

A new 3D cobalt metal-organic framework [C_7H_（13）N_2]_2[（CH_3COO）_2Co_7（oba）_5-（Hoba）_2（OH）_2]·H_2O has been synthesized under ionothermal conditions and characterized by elemental analysis, FT-IR, XRD, and TG. This complex crystallizes in monoclinic system, space group P21/c with a = 19.4499（4）, b = 10.8839（2）, c = 27.7796（5） ？, β = 104.467（2）o, V = 5694.22（19） ？~3, Z = 2, C_（116）H_（92）Co_7N_4O_（42）, M_r = 2626.45, D_c = 1.532 g/cm^3 , F（000） = 2682, μ = 1.085 mm-1, R = 0.0387 and wR = 0.1177. Its structure is characterized as a 3D open framework constructed by seven nuclear clusters [（CH_3COO）_Co_7（OH）_2] and the 4,4？-oxybisbenzoic acid ligand. The used ILs cations are located in the middle of the pore and compensate for the negative charges of framework. Furthermore, its fluorescence property has also been studied.

Co-templating Ionothermal Synthesis and Crystal Structure of a New Layered Aluminophosphate from a Protic Deep Eutectic Solvent

Protic deep eutectic mixtures are usually composed of organic amine hydrochloride salts and hydrogen bond donors in a specific molar ratio. Ionothermal synthesis of aluminophosphate as an example, herein, was reported for the first time from an urea-based protic eutectic mixture, consisting of diethylammonium chloride （DEACI） and 1,3-dimethyl urea （DMU）. As a result, a new two dimensional aluminophosphate with 4.8-network, [CH3NH3]2[（C2H5）2NH2]Al3（PO4）4, has been successfully synthesized by co-templating the DEA and methylamine in situ generated from the decomposition of DMU in the absence of HF. Compared to alkyl quaternary ammonium salts with more alkyl-group connected with N atom, this kind of organic amine salts are more likely as the struc- ture-directing agents to synthesize aluminophosphates in urea-based deep eutectic mixtures. It was also found that HF is crucial to the phase selectivity, a known compound with chain-like structure was obtained with the single methylamine as a structure-directing agent in the presence of HF. These materials were characterized by powder XRD, SEM, TG-DSC, 13C CP-MAS NMR and CHN analyses.

Ionothermal Synthesis and Structural Characterization of a Novel Open Framework Zinc Diphosphonate with Carboxylate-like Linker

A novel crystalline zinc diphosphonate, （CH3NH3）4Zn2（xbp）2·H2O, denoted as compound 1, was ionothermally synthesized from tetraethyl-p-xylylenebisphosphonate （Yexbp） and Zn（OAc）2 in a protic eutectic mixture with urea/methylamine hydrochloride. Its structure was determined by single-crystal X-ray diffraction data and had a special three-dimensional open framework with rhombic channels. Compound 1 belongs to the monoclinic system （space group C2/c）, with lattice parameters a=22.6876（19）A, b=8.7376（7）A, c=8.1673（9）A, β= 108.146（2）°, V= 1538.5（2） A^3, Z=2. Its structure is totally different from the typical organic pillared structure, only two oxygens of the phosphonate group are coordinated with zinc atoms, and the third oxygen exists in the terminal form, which is similar to the popular dicarboxylate linkers in MOFs. The organic cations [CH3NH3]^＋ of the eutectic mixture played a structure-directing role for constructing this framework and were confined in the pore channels to balance the negative charges resulting from the zinc phosphonate inorganic chains.

Ionothermal synthesis of AlPO-34 membranes on macroporous α-Al_(2)O_(3) supports without using organic template

Continuous and compact AlPO-34 molecular sieve membranes were successfully synthesized on the outer surface of macroprous tubeα-Al_(2)O_(3)supports under secondary ionothermal growth with the proposed wetting seed layer.The recyclable ionic liquids(ILs)can both act as solvent media and the structure-directing agent(SDA)of the aiming topological structure of CHA,largely reducing the wastewater.Wetting the seed layer could accelerate the diffusion of ILs to the surface of the support and further increase the binding force between the membrane and the support.Compared with the open system,the closed system led to the achievement of the high-quality AlPO-34 membrane.The H_(2)permeance of the resulting membrane was 9.74×10^(-8)mol m^(-2)s^(-1)Pa^(-1)and the ideal selectivities of H_(2)/CO_(2),H_(2)/N_(2),H_(2)/CH_(4),H_(2)/C3H8 and H_(2)/i-C4H10 were 7.48,8.54,14.67,39.25 and 65.83,respectively,which were higher than Knudsen diffusion ratios.The obtained membrane was firstly explored for the PV dehydration of isopropyl alcohol(90 wt%)/water mixtures,exhibiting good performance with the separation factor of 147 and high water flux of 1.09 kg m^(-2)h^(-1).

Atomically Precise Titanium–Oxo Nanotube with Selective Water Adsorption and Semiconductive Behaviors

We report the first example of carbon nanotube(CNT)-like assembly of the titanium(Ti)framework,Ti oxo inorganic cluster(Ti6O6)hexagonal rings into a titanium oxide(Ti–O)nanotube,prepared by ionothermal synthesis.As determined by single-crystal X-ray diffraction analysis,the Ti–O nanotube arrays,stabilized by sulfate ligands,assumed proper parallel alignment with each other and were separated by supramolecular interactions with surrounding EMIm(1-Ethyl-3-methylimidazolium)counter cations.Our stability studies indicated that the Ti–O nanotube obtained is indeed stable in air and various solvents.Also,it could maintain its structure upon heating to∼300°C.Moreover,inside the pores of the Ti–O nanotubes,a rare water molecules nanoconfinement behavior was observed at room temperature.Further,our current developed Ti–O nanotube arrays exhibited selective water adsorption over methanol and ethanol,showing potential applications for miscible solvents separations.Finally,these Ti–O nanotubes demonstrated typical semiconductive characteristics,with the electrical conductivity increasing four orders of magnitude,ranging from 3.15×10^(−10)–1.03×10^(−6)S/cm,as the temperature increased from 35 to 135°C.This work represents a milestone in constructing inorganic Ti–O nanotube arrays with atomically precise structural information for applications as visible-lightinduced photocatalysts,semiconductors,sensors,and optoelectronics.