Progress in Preparation and Application of Gel-Emulsions

Compared to conventional emulsions, gel-emulsions have a higher internal phase volume fraction, unique structures and properties, higher viscosity, and tunable internal structures. These advantages make them widely applicable in the cosmetics industry, food industry, aerospace, and biomedicine, with significant potential in the development of new materials and high-performance products. The factors affecting the stability of gel-emulsions, as well as the types of stabilizers required for their preparation (including solid particles, surfactants, and small molecule gelators), and the corresponding preparation methods (including the one-step method, two-step method, and phase inversion method) are reviewed in this article. The applications of gel-emulsions in porous materials, food, cosmetics, and stimuli-responsive materials are introduced, and future research directions are also discussed.

Significantly Enhanced Electromagnetic Interference Shielding Performances of Epoxy Nanocomposites with Long-Range Aligned Lamellar Structures

High-efficiency electromagnetic interference(EMI)shielding materials are of great importance for electronic equipment reliability,information security and human health.In this work,bidirectional aligned Ti_(3)C_(2)T_(x)@Fe_(3)O_(4)/CNF aerogels(BTFCA)were firstly assembled by bidirectional freezing and freeze-drying technique,and the BTFCA/epoxy nanocomposites with long-range aligned lamellar structures were then prepared by vacuum-assisted impregnation of epoxy resins.Benefitting from the successful construction of bidirectional aligned three-dimensional conductive networks and electromagnetic synergistic effect,when the mass fraction of Ti_(3)C_(2)T_(x) and Fe_(3)O_(4) are 2.96 and 1.48 wt%,BTFCA/epoxy nanocomposites show outstanding EMI shield-ing effectiveness of 79 dB,about 10 times of that of blended Ti_(3)C_(2)T_(x)@Fe_(3)O_(4)/epoxy(8 dB)nanocomposites with the same loadings of Ti_(3)C_(2)T_(x) and Fe_(3)O_(4).Meantime,the corresponding BTFCA/epoxy nanocomposites also present excellent thermal stability(T_(heat-resistance index) of 198.7℃)and mechanical properties(storage modulus of 9902.1 MPa,Young’s modulus of 4.51 GPa and hardness of 0.34 GPa).Our fabricated BTFCA/epoxy nanocomposites would greatly expand the applications of MXene and epoxy resins in the fields of information security,aerospace and weapon manufacturing,etc.

Synthesis, Crystal Structure and Biological Activity of 1-(3-Amino-4-morpholino-1H-indazole-1-carbonyl)-N-(4-fluorophenyl)cyclopropane-1-carboxamide

The title compound 1-(3-amino-4-morpholino-1H-indazole-1-carbonyl)-N-(4-fluorophenyl)cyclopropane-1-carboxamide was synthesized by the condensation of 1-[(4-fluorophenyl)carbamoyl]cyclopropane-1-carboxylic acid with 4-morpholino-1H-indazol-3-amine.This intermediate was prepared from 2,6-difluorobenzonitrile by the condensation with morpholine and then cyclisation with hydrazine hydrate.The crystal structure of the title compound was determined to be of monoclinic system,space group P21/c with a=10.4645(13),b=17.368(2),c=13.7220(13)? and β=21.446(7)°.In addition,the compound possesses distinct effective inhibition on the proliferation of HT-29,MKN-45,K562 and A549 cell lines.

Effect of pH/Auxiliary Ligand on the Structures of Coordination Compounds Based on a Novel Ligand 2,6-Bis(pyrazin-2-yl)pyridine-4-carboxylate

Four new coordination compounds, [Zn（bppc）2（H2O）2]·3 H2O（1）, [Zn2（bppc）2（mbdc）（H2O）4]·7 H2O（2）, [Zn（bppc）2（H2O）2]n·n（m-Hbdc）·n（H2O）（3）, [Zn2（bppc）（btc）（H2O）3]n·5 n H2O（4）（Hbppc = 2,6-bis（pyrazin-2-yl）pyridine-4-carboxylate, H2（m-bdc） = 1,3-benzenedicarboxylic acid, H3 btc = 1,3,5-benzene-tricarboxylic acid）, have been hydrothermally synthesized and structurally characterized. Compound 1 shows a mononuclear structure and 2 shows a dinuclear structure. Compound 3 is a one-dimensional chain structure, which is extended into a 3D supramolecular network by intermolecular hydrogen interactions. In 4, a 1D loop-like chain is connected by（btc）^3-anions to generate a 2D layer structure. The structure differences of 1~4 show that the p H and aromatic acid as auxiliary ligand have important influence on the final structures.iAdditionally, the luminescent properties of 1~4 have been investigated with fluorescent spectra in the solid state, and 1~4 display a strong fluorescent emission at room temperature and have potential applications as fluorescent-emitting materials.

Core-Shell Structure of NaYF4@SiO2@Au Nanocomposite of Synthesis and Characterization with Mechanisms Research

A facile method for preparing monodisperse NaYF4@SiO2@Au core-shell nanocomposite was developed. Transmission electron microscopy(TEM) as well as EDX(energy dispersive X-ray) was used to characterize the samples. The TEM showed the composite was a core-shell structure, spherical,with the uniform size of about 100 nm. TEM and EDX revealed that the NPs were coated with a layer of SiO2 and Au shell. The core shell structure of NaYF4@SiO2@Au nanocomposite could dispersed in water easily. More importantly,after being coated with SiO2 and Au, it was feasible for function by-SH and-NH2 groups, respectively. The forming process of the Au shell was monitored with TEM. The mechanism of coating Au shell was discussed in detail. It is expected that the core shell nanoparticle will act as multifunctional molecular imaging probes, such as positron emission tomography(PET), magnetic resonance imaging(MRI), optical imaging(OI), or contrast agent for sensing and detection.

Coprecipitation Synthesis of Fluorides Nanoparticles with Multiform Structures and Mechanisms Research

Fluoride nanoparticles with multiform crystal structures and morphologies were successfully synthesized by a facile, effective, and environmentally friendly coprecipitation method. Transmission electron microscopy (TEM) was used to characterize the nanoparticles. The nanoparticles were modified by PEI, CTAB, PAA and Ci, respectively. It was feasible for function by -COOH and -NH2 groups, due to the surface modification. Moreover, different surface modifications of the nanoparticles were examined. The possible formation mechanisms for fluoride nanoparticles with surface modification were presented in detail. More importantly, it is expected to be widely applied to biomedicine.

Theoretical Prediction of the Photovoltaic Properties of BFBPD-PC61 BM System as a Promising Organic Solar Cell

In this work,the photovoltaic properties of BFBPD-PC61 BM system as a promising high-performance organic solar cell（OSC） were theoretically investigated by means of quantum chemistry and molecular dynamics calculations coupled with the incoherent charge-hopping model.Moreover,the hole carrier mobility of BFBPD thin-film was also estimated with the aid of an amorphous cell including 100 BFBPD molecules.Results revealed that the BFBPD-PC61 BM system possesses a middle-sized open-circuit voltage of 0.70 V,large short-circuit current density of 17.26 mA ·cm^-2,high fill factor of 0.846,and power conversion efficiency of 10%.With the Marcus model,in the BFBPD-PC61 BM interface,the exciton-dissociation rate,kdis,was predicted to be 2.684×10^13 s^-1,which is as 3-5 orders of magnitude large as the decay（radiative and non-radiative） one（10-8-10^10s^-1）,indicating a high exciton-dissociation efficiency of 100% in the BFBPD-PC61 BM interface.Furthermore,by the molecular dynamics simulation,the hole mobility of BFBPD thin-film was predicted to be as high as 1.265 × 10^-2 cm-2·V^-1·s^-1,which can be attributed to its dense packing in solid state.

Amine-functionalized hierarchically porous carbon supported Pd nanocatalysts for highly efficient H2 generation from formic acid with fast-diffusion channels

Formic acid(FA)has come to be considered a potential candidate for hydrogen storage,and the development of efficient catalysts for H2releasing is crucial for realizing the sustainable process from FA.Herein,we have developed the ultrafine Pd nanoparticle(NPs)with amine-functionalized carbon as a support,which was found to show an excellent catalytic activity in H_(2)generation from FA dehydrogenation.The synergetic mechanism between amine-group and Pd active site was demonstrated to facilitate H2generation byβ-hydride elimination.Moreover,the texture of support for Pd NPs also plays an important role in determining the reactivity of FA,since the diffusion of gaseous products makes the kinetics of diffusion as a challenge in this high performance Pd catalysts.As a result,the as-prepared Pd/NH_(2)-TPC catalyst with the small sized Pd nanoparticles and the hierarchically porous structures shows a turnover of frequency(TOF)value of 4312 h^(-1)for the additive-free FA dehydrogenation at room temperature,which is comparable to the most promising heterogeneous catalysts.Our results demonstrated that the intrinsic catalytic activities of active site as well as the porous structure of support are both important factors in determining catalytic performances in H2generation from FA dehydrogenation,which is also helpful to develop high-activity catalysts for other advanced gas-liquid-solid reactions systems.

Fabrication and photocatalysis of ZnO nanotubes on transparent conductive graphene-based flexible substrates

Zinc oxide （ZnO） is one of the most widely used benchmark standard photocatalysts in the field of en- vironmental applications [1-3]. As a wide band-gap semiconductor oxide （Eg=3.37 eV） with large excitation binding energy （60 meV）, zinc oxide becomes one of the most important functional materials with unique prop- erties of optical transparency, electric conductivity and piezo electricity [4-10]. However, the large band gap and the massive recombination of photogenerated charge carriers, especially in its nanosize.

Breaking the activity limitation of iridium single-atom catalyst in hydrogenation of quinoline with synergistic nanoparticles catalysis

Single-atom catalysts(SACs)with the advantages of homogeneous and heterogeneous catalysts have become a hot-spot in catalysis field.However,for lack of metal–metal bond in SACs,H_(2)has to go through heterolytic dissociation pathway,which has higher barrier than homolytic dissociation pathway,and thus limits the hydrogenation activity of SACs.Herein,we propose and demonstrate through constructing synergistic iridium single atoms and nanoparticles co-existed catalyst(denoted as Ir_(1+NPs)/CMK)to boost the catalytic activity of quinoline hydrogenation.Both experimental and density functional theory calculation results confirm that Ir_(1)single sites activate quinoline,while Ir nanoparticles boost hydrogen dissociation.H atoms generated at Ir nanoparticles migrate to the quinoline bounded Ir_(1)single sites to complete hydrogenation.The Ir_(1+NPs)/CMK catalyst exhibits much higher reactivity with turnover frequency of 7,800 h^(−1)than those counterpart Ir_(1)/CMK and IrNPs/CMK catalysts,and is 20,000 times higher activity of commercial Ir/C benchmark catalyst for hydrogenation of quinoline under the same reaction conditions.This synergistic catalysis strategy between single atoms and nanoparticles provides a solution to further improve the performance of SACs for hydrogenation.

Temperature and doping dependent flat-band superconductivity on the Lieb-lattice

We consider the superconducting properties of Lieb lattice, which produces a flat-band energy spectrum in the normal state under the strong electron–electron correlation. Firstly, we show the hole-doping dependent superconducting order amplitude with various electron–electron interaction strengths in the zero-temperature limit. Secondly, we obtain the superfluid weight and Berezinskii–Kosterlitz–Thouless(BKT) transition temperature with a lightly doping level. The large ratio between the gap-opening temperature and BKT transition temperature shows similar behavior to the pseudogap state in high-T_(c) superconductors. The BKT transition temperature versus doping level exhibits a dome-like shape in resemblance to the superconducting dome observed in the high-T_(c) superconductors. However, unlike the exponential dependence of T_(c) on the electron–electron interaction strength in the conventional high-T_(c) superconductors, the BKT transition temperature for a flat band system depends linearly on the electron–electron interaction strength. We also show the doping-dependent superconductivity on a lattice with the staggered hoping parameter in the end. Our predictions are amenable to verification in the ultracold atoms experiment and promote the understanding of the anomalous behavior of the superfluid weight in the high-T_(c) superconductors.

Significant Enhancement in Photovoltaic Performances for C217-based Dye Sensitizers via Introducing Electron-withdrawing Substituents: a Theoretical Study

Dye-sensitized solar cells(DSSCs) are one of the most promising photovoltaic technologies, and the development of efficient dye sensitizers, especially inexpensive metal-free organic dyes, is always crucial for fabricating new DSSC devices. In this paper, a series of novel metal-free dyes with the D-A-π-A structure were designed by introducing electron-withdrawing substituents into the C217 molecular skeleton, and then their photovoltaic parameters were predicted by means of density functional theory(DFT) and time-dependent DFT(TD-DFT) calculations in combination with the Marcus charge transfer model. Our results showed that compared with C217, the introduction of trifluoromethyl(-CF3), cyano(-CN), and nitryl(-NO2) can efficiently narrow the HOMO-LUMO gap, and remarkably enhance the dye’s sunlight harvesting. With the(TiO2)38 cluster model, the photoelectric conversion efficiency(PCE) for the C217 dye was predicted to be up to 9.82%, which is in good agreement with the measured value(9.6%~9.8%), suggesting that our scheme used in this paper is reliable. Based on the same method, the PCE of most designed dyes was estimated to exceed over 10%, denoting that the molecular design strategy recommended by us in this work is reasonable. Especially, the PCE values of the dye 1, 4, and 6 were found to be as high as 14.75%, 16.02% and 15.75% respectively, suggesting that these three dyes are potential candidates as efficient sensitizers, and are worth further experimental study.

Computational Prediction of Graphdiyne-Supported Three-Atom Single-Cluster Catalysts

While heterogeneous single-atom catalysts(SACs)have achieved great success in the past decade,their application is potentially limited by their simplistic single-atom active centers,which make single-cluster catalysts(SCCs)a natural extension in the domain of heterogeneous catalysis.SCCs with precise numbers of atoms and structural configurations possess SAC merits,yet have greater potential for catalyzing complex reactions and/or bulky reactants.Through systematic quantum-chemical studies and computational screening,we report here the rational design of transition metal three-atom clusters anchored on graphdiyne(GDY)as a novel kind of stable SCC with great promise for efficient and atomically precise heterogenous catalysis.By investigating their structure and catalytic performance for the oxygen reduction reaction,the hydrogen evolution reaction,and the CO_(2)reduction reaction,we have provided theoretical guidelines for their potential applications as heterogeneous catalysts.These GDY-supported three-atom SCCs provide an ideal benchmark scaffold for rational design of atomically precise heterogeneous catalysts for industrially important chemical reactions.

Research progress of“rocking chair”type zinc-ion batteries with zinc metal-free anodes

"Rocking chair"type lithium-ion batteries with lithium metal-free anodes have been successfully com-mercialized over the past few decades.Zinc-ion batteries(zIBs)have gained increasing attention in recent years given their safety,greenness,ease of manufacture,and cost-efficiency.Nevertheless,the practical application of ZIBs is largely hindered by the dendritic growth of the Zn metal anode,low Coulombic eficiency,great harm,and existence of various side reactions.Herein,this review provides a systematic overview of emerging"rocking chair"type ZIBs with zinc metal-free anodes.Firstly,the basic fundamen-tals,advantages,and challenges of“rocking chair”type ZIBs are introduced.Subsequently,an overview of the design principles and recent progress of"rocking chair"type ZIBs with zinc metal-free anodes are presented.Finally,the key challenges and perspectives for future advancement of"rocking chair"type ZiBs with zinc metal-free anodes are proposed.This review is anticipated to attracted increased focus to metal-free anodes"rocking chair"type metal-ion battery and provide new inspirations for the develop-ment of high-energy metal-ion batteries.

Multiple evaluations of atmospheric behavior between Criegee intermediates and HCHO: Gas-phase and air-water interface reaction

Given the high abundance of water in the atmosphere,the reaction of Criegee intermediates(CIs)with(H_(2)O)_(2) is considered to be the predominant removal pathway for CIs.However,recent experimental findings reported that the reactions of CIs with organic acids and carbonyls are faster than expected.At the same time,the interface behavior between CIs and carbonyls has not been reported so far.Here,the gas-phase and air-water interface behavior between Criegee intermediates and HCHO were explored by adopting high-level quantum chemical calculations and Born-Oppenheimer molecular dynamics(BOMD)simulations.Quantum chemical calculations evidence that the gas-phase reactions of CIs+HCHO are submerged energy or low energy barriers processes.The rate ratios speculate that the HCHO could be not only a significant tropospheric scavenger of CIs,but also an inhibitor in the oxidizing ability of CIs on SO_(x) in dry and highly polluted areas with abundant HCHO concentration.The reactions of CH_(2)OO with HCHO at the droplet’s surface follow a loop structure mechanism to produce i)SOZ(■),ii)BHMP(HOCH_(2)OOCH_(2)OH),and iii)HMHP(HOCH_(2)OOH).Considering the harsh reaction conditions between CIs and HCHO at the interface(i.e.,the two molecules must be sufficiently close to each other),the hydration of CIs is still their main atmospheric loss pathway.These results could help us get a better interpretation of the underlying CIs-aldehydes chemical processes in the global polluted urban atmospheres.

Selective hydrogenation of acetylene on graphene-supported non-noble metal single-atom catalysts

Large-scale production of polyethylene in industry requires efficient elimination of the trace amount of acetylene impurity.Currently,zeolite adsorption or the conversion of acetylene to ethylene via selective semi-hydrogenation on Pd catalysts is the commonly used method.In this work,we investigate the reaction mechanisms of acetylene hydrogenation on defective graphene(DG)supported singleatom catalysts(SACs),M1/SV-G and M1/DV-G(M=Ni,Pd and Pt)using density functional theory(DFT),where SV-G and DV-G represent DG with single and double vacancies,respectively.It is shown that the metal single-atoms(SAs)as well as their different coordination numbers both affect the activity and selectivity of the hydrogenation process.M1/DV-G provides better H2 dissociation ability than M1/SV-G,which accounts for the poor acetylene hydrogenation activity of M1/SV-G.Based on the reaction barriers,Pt1/DV-G and Ni1/DV-G are better catalysts than other systems considered here,with Ni1/DV-G exhibiting high selectivity for the semi-hydrogenation product of acetylene.These results provide insights for the design of highly selective and noble-metal-free SACs for acetylene hydrogenation on carbon materials.

Non-noble metal single-atom catalysts with phosphotungstic acid(PTA)support:A theoretical study of ethylene epoxidation

Geometric and electronic structures of phosphotungstic acid(PTA)supported single transition metal atom(Fe,Co,Ni,Ru,Rh,Pd,Os,Ir and Pt)catalysts have been systematically investigated by using the first-principles theoretical methods.Possible reaction mechanism for ethylene epoxidation was explored.The most possible anchoring site for the single transition metal atom is the fourfold hollow site on PTA.As the non-noble metal Fe1-PTA system possesses considerable adsorption energies towards both O2 and C2H4,the strong bonding interaction between Fe1 and PTA cluster was analyzed.It is found that the electron transfers from Fe atom to PTA cluster and strong covalent metal-support interactions(CMSI)between the Fe 3 d orbitals and O 2 p orbitals of PTA lay the foundation of high stability.The proposed catalytic reaction mechanism for ethylene epoxidation on Fe1-PTA single-atom catalyst(SAC)includes three steps:the O2 adsorbs on Fe1-PTA via electron transfer;the first ethylene attacks the adsorbed O2 molecule on Fe1-PTA followed by the formation of C2H4O;finally,the O atom remained on Fe1-PTA reacts with a second ethylene to form the product and accomplish the catalytic cycle.The Fe1-PTA has high selectivity and catalytic activity for ethylene epoxidation via an Eley–Rideal mechanism with low energy barriers.A potentially competitive pathway for the formation of acetaldehyde is not kinetically favorable.These results provide insights for the development of highly efficient heterogeneous SACs for ethylene epoxidation with non-noble metals.

Advances in green synthesis and applications of graphene

Green synthesis has grabbed appreciable attention to eliminate the negative effects associated with various chemical processes. Due to the unparalleled electrical, mechanical, thermal and excellent physical properties, graphene, as the thinnest two-dimensional material with high surface area, has the unfathomable potential in the domain of green chemistry in terms of both synthesis and application. In this regard, we present an overview of the research progresses on the greener synthesis of graphene, including micromechanical exfoliation, chemical reduction of graphene oxide (GO), chemical vapor synthesis and popping of GO. Meanwhile, various applications of graphene pertinent to sustainable developments, such as energy storage, catalysis, electrochemistry, fuel cell, supercapacitor and biomedicine have also been highlighted.

Non-noble metal single-atom catalyst of Co_(1)/MXene(Mo_(2)CS_(2))for CO oxidation

MXene is a variety of new two-dimensional(2D)materials with early transition metal carbides,nitrides,and carbonitrides.Quantum chemical studies have been carried out on the geometries,electronic structures,stability and catalytic properties of a non-noble metal single-atom catalyst(SAC)with single Co atom anchored on MXene materials of Mo_(2)CS_(2).The Co adatom anchored on top of the Mo atom of this MXene is found to be rather stable,and this SAC is appropriate for CO oxidation.The charge transfers from the surface to the adsorbed CO and O2 play a significant role in the activation of these molecules on Co_(1)/Mo_(2)CS_(2).With this catalyst,the Eley-Rideal(ER),Langmuir-Hinshelwood(LH),and Termolecular Eley-Rideal(TER)mechanisms are explored for CO oxidation.We find that,while all the three mechanisms are feasible at low temperature,Co_(1)/Mo_(2)CS_(2) possesses higher catalytic activity for CO oxidation through the TER mechanism that features an intriguing OC(OO)CO intermediate(IM)adsorbed on Co single atom.The calculated activation energy barriers of the rate-limiting step are 0.67 eV(TER),0.78 eV(LH)and 0.88 eV(ER),respectively.The present study illustrates that it is promising to develop and design low-cost,non-noble metal SACs using MXene types of 2D materials.

Adsorption of Nin（n=1-4）clusters on perfect and O-defective CuAl2O4 surfaces:A DFT study

The density functional theory was employed to investigate the adsorption of Nin (n=1–4) on the perfect and O-defect CuAl2O4 surfaces. The computational results show that for single Ni atom on the perfect spinel (100) surface, the adsorption energy is-5.30 eV, much larger than Ni on other CuAl2O4 surfaces. The adsorption of Nin (n=1–4) absorbed on the O-defect CuAl2O4 (100) surface is less stable than on the perfect CuAl2O4 (100) surface. However, the adsorption energy for Nin (n=1–4) on the O-defect CuAl2O4 (110) surface is close to on the perfect CuAl2O4 (110) surface. Bader charge and partial density of states (PDOS) analysis revel that the adsorption of Ni on the CuAl2O4 spinel surface is accompanied by charge transfer from the metal to the support. The growth and aggregations analysis show that the general growth and aggregation ability for Nin clusters follow the order:gas phase>γ-Al2O3 (110)>CuAl2O4 (110)>CuAl2O4 (100). This result can give reasonable explanations for the experimental phenomenon that Ni supported on the CuAl2O4 spinel performs much better stability than on the γ-Al2O3.