In-situ incorporation of halloysite nanotubes with 2D zeolitic imidazolate framework-L based membrane for dye/salt separation

Layered assembled membranes of 2D leaf-like zeolitic imidazolate frameworks(ZIF-L)nanosheets have received great attention in the field of water treatment due to the porous structure and excellent antibacterial ability,but the dense accumulation on the membrane surface and the low permeate flux greatly hinder their application.Herein,we synthesized m HNTs(modified halloysite nanotubes)/ZIF-L nanocomposites on modified m HNTs by in situ growth method.Interestingly,due to the different size of m HNTs and ZIF-L,m HNTs were packed in ZIF-L nanosheets.The hollow m HNTs provided additional transport channels for water molecules,and the accumulation of the ZIF-L nanosheets was decreased after assembling m HNTs/ZIF-L nanocomposites into membrane by filtration.The prepared m HNTs/ZIF-L membrane presented high permeate flux(59.6 L·m^(-2)·h^(-1)),which is 2-4 times of the ZIF-L membranes(14.8 L·m^(-2)·h^(-1)).Moreover,m HNTs/ZIF-L membranes are intrinsically antimicrobial,which exhibit extremely high bacterial resistance.We provide a controllable strategy to improve 2D ZIF-L assembles,and develops novel membranes using 2D package structure as building units.

Advances and challenges of electrolyzers for large-scale CO_(2) electroreduction

CO_(2) electroreduction(CO_(2) ER)to high value-added chemicals is considered as a promising technology to achieve sustainable carbon neutralization.By virtue of the progressive research in recent years aiming at design and understanding of catalytic materials and electrolyte systems,the CO_(2) ER performance(such as current density,selectivity,stability,CO_(2) conversion,etc.)has been continually increased.Unfortunately,there has been relatively little attention paid to the large-scale CO 2 electrolyzers,which stand just as one obstacle,alongside series-parallel integration,challenging the practical application of this infant technology.In this review,the latest progress on the structures of low-temperature CO_(2) electrolyzers and scale-up studies was systematically overviewed.The influence of the CO_(2) electrolyzer configurations,such as the flow channel design,gas diffusion electrode(GDE)and ion exchange membrane(IEM),on the CO_(2) ER performance was further discussed.The review could provide inspiration for the design of large-scale CO_(2) electrolyzers so as to accelerate the industrial application of CO_(2) ER technology.

Purification of specularite by centrifugation instead of flotation to produce iron oxide red pigment

This study used specularite, a high-gradient magnetic separation concentrate, as a raw material in reverse flotation.An iron concentrate with a grade of 65.1 wt% and a recovery rate of 75.31% were obtained.A centrifugal concentrator served as the deep purification equipment for the preparation of iron oxide red pigments, and its optimal rotating drum speed, feed concentration, and other conditions were determined.Under optimal conditions, a high-purity iron oxide concentrate with a grade of 69.38 wt% and a recovery rate of 80.89% were obtained and used as a raw material for preparing iron oxide red pigment.Calcining with sulfuric acid produced iron red pigments with different hues.Simultaneously, middlings with a grade of 60.20 wt% and a recovery rate of 17.51% were obtained and could be used in blast furnace ironmaking.High-value utilization of specularite beneficiation products was thus achieved.

Rare earth metal based DES assisted the VPO synthesis for n-butane selective oxidation toward maleic anhydride

Deep eutectic solvents(DESs) are now considered a new class of ionic liquid analogs that have been generously used in various fields.Herein, vanadium phosphorus oxide(VPO) catalysts are synthesized in combination with a deep eutectic solvent containing rare earth metal(rE-DES), and their catalytic performance in n-butane selective oxidation to produce maleic anhydride(MA) is evaluated. The rE-DES is produced from the interaction of choline chloride(ChCl) and rare earth metal salts(Cerium, Europium, Lanthanum, and Samarium metal salt)(ChCl:rE = 1:0.5–1:3) under mild conditions. It was found that DESs served as structural modifiers and electronic promoters during VPO synthesis. It regulated the chemical state of the catalyst surface, such as the vanadium valence state, acid-base properties, and ratios of V^(4+)/V^(5+),Lat–O/Sur–O and P/V. Various characterization techniques, such as FT-IR, DSC, XRD, SEM, EDS, TEM, Raman, TGA, NH3-TPD, and XPS,were used to examine its physical and chemical characteristics. These characteristics were correlated with the catalytic performance. The VPO catalyst modified by rE-DES showed a significant enhancement of n-butane conversion and MA selectivity while suppressing the selectivity of CO and CO_(2)as well as the CO/CO_(2)ratio compared to the unpromoted VPO catalyst. Especially for Ce-DES-VPO, it increased the n-butane conversion and MA mass yield up to approximately 11% and 10%, respectively. In addition, we evaluated the catalytic performance under different activation atmospheres.

Study on ionic liquids based novel method for separation and purification of silkworm pupa protein

Silkworm pupa protein(SPP)that obtained by traditional method usually had a high fat content,which would impose restrictions on the further use of SPP.Herein,various functionalized ionic liquids(ILs)were used to extract SPP from silkworm pupae,the structure-performance relationship of ILs with their SPP separation performance were explored at the same time.The research showed that the maximum extraction yield of SPP was up to 62.6%with less than 0.5%low fat content by using 1-ethyl-3-methylimidazolium chloride([Emim]Cl),when the dissolution experiment was conducted at 90°C for 24 h with ethanol bath as the regeneration solvent.Comparing with the structure of raw material,the regenerated SPP maintained the native protein backbone.Meanwhile,all regenerated SPP showed a decreased crystallinity,which also exhibited decreased fraction of theα-helix comparing to thatβ-sheet united with coil random structures.

Recent Advances in Biomass-derived Porous Carbon Materials:Synthesis,Composition and Applications

Porous carbon materials(PCMs)play a pivotal role in diverse applications,such as energy storage,adsorption,catalysis,environmental remediation,and microwave adsorption.The selection of carbon precursors,in particular,is crucial for tailoring porous structures with specific functionalities.Biomass,with its rich carbon feedstock,abundant availability,renewability,and versatile structures,has emerged as a promising precursor for porous carbon material synthesis.This review comprehensively summarizes the recent advances in biomass-derived porous carbon materials(BPCMs)encompassing synthetic strategy,morphology,structural composition,and multiple applications.We first review synthetic approaches aiming at regulating porosity,followed by morphological and composition features of BPCMs,with a special emphasis on elucidating the dimensional clarification and heteroatom doping effects.The discussion then extends to the wide-ranging applications of BPCMs,covering energy-related applications and CO_(2) adsorption to environmental remediation.Finally,the review outlines the existing challenges and prospects in the field.In summary,this review systematically describes BPCMs and provides valuable guidance for researchers to select and synthesize BPCMs that meet specific functional requirements.

Ionic liquid-trimetallic electrocatalytic system for C–O bond cleavage in lignin model compounds and lignin under ambient conditions

Electrocatalytic depolymerization of lignin into value-added chemicals offers a promising technique to make biorefining sustainable.Herein,we report a robust trimetallic PdNiBi electrocatalyst for reductive C–O bond cleavage of different lignin model dimers and oxidized lignin under mild conditions.The reduction reaction proceeds with complete substrate conversion and excellent yields toward monomers of phenols(80%–99%)and acetophenones(75%–96%)in the presence of an ionic liquid electrolyte with operational stability.Systematic experimental investigations together with density functional theory(DFT)calculations reveal that the outstanding performance of the catalyst results from the synergistic effect of the metal elements,which facilitates the easier formation of a key Cαradical intermediate and the facile desorption of the as-formed products at the electrode.The results open up new opportunities for lignin valorization through the green electrocatalytic approach.

Comparative studies on fouling of homogeneous anion exchange membranes by different structured organics in electrodialysis

Five negatively charged organic compounds with different structures, sodium methane sulfonate(MS), sodium benzene sulfonate(BS), sodium 6-hydroxynaphthalene-2-sulfonate(NSS), sodium dodecyl sulfate(SDS), and sodium dodecyl benzene sulfonate(SDBS), were used to examine the fouling of an anion exchange membrane(AEM) in electrodialysis(ED),to explore the effect of molecular characteristics on the fouling behavior on the AEM and changes in the surface and electrochemical properties of the AEM. Results indicated that the fouling degree of the AEM by the different organics followed the order:SDBS > SDS > NSS > BS > MS. SDBS and SDS formed a dense fouling layer on the surface of the AEM, which was the main factor in the much more severe membrane fouling, and completely restricted the transmembrane ion migration. The other three organics caused fouling of the AEM by adsorption on the surface and/or accumulation in the interlayer of the AEM, and exhibited almost no influence on the transmembrane ion migration. It was also concluded that the organics with benzene rings caused more severe fouling of the AEM due to the stronger affinity interaction and steric effect between the organics and the AEM compared with organics with aliphatic chains.

Efficient Extraction of Lithium Ions from High Mg/Li Ratio Brine through the Synergy of TBP and Hydroxyl Functional Ionic Liquids

of main observation and conclusion The extraction of Li^+from the high Mg/Li ratio brine was performed using hydroxyl functional ionic lic-uids(ILs)as the coextractant and tributyl phosphate(TBP)as the extractant.irsty the extractive system,1-2-hydroxyethyl-3-mnethylimidazolumbis(trifuoromethylsulfonyl)imide([HOEmim][NTf2])+TBP was proved to exhibit the highest extraction efficiency of Li^+(88.15%)from LiCl aqueous solutions among the extractants composed of differents TB P,and ls+TBP.Effects of various extraction parameters on the extraction eficiencies of Li^+and Mg^2+were then investigated.95.01%of Li^+was extracted and the Li^+/Mg^2+separation factor reached 405.76 in a singl-stage at 278.15 Kand O/A of 2:1.The extraction complexes were determined by the slope analysis method and ESI-MS analysis,and the metal complexes in the organic phase were indcated to be mainly[L-2TBP][NTf;J.The striping study showed that 92.86%of i*was stripped with 1.0 mol·L^-1 HCl.98%extraction capacity of the synergyextractants was remained after 5 regeneration cycles.The thermodynamic parameters(△G°,△H°,and△S°),together with the mechanism of the Li^+extraction were further demonstrated finally,According to the results,[HOEmim][NTf2]+TBP extraction system showed promising performance in extracting lithium from salt lake brine with high Mg/Li ratio.

Improved thermal conductivity of epoxy resin by graphene-nickel three-dimensional filler

Owing to high thermal conductivity,carbon nanotube and graphene have been used as nanofillers to improve the thermal conductivity of polymer.However,the agglomeration of nanofillers in polymer inhibits their applications in improving the thermal conductivity of composite.To overcome this problem,graphene was grown on Ni foam by chemical vapor deposition in this work.And graphene-nickel three-dimensional filler was added into epoxy resin to improve the thermal conductivity of epoxy resin.Ni foam can prevent the agglomeration of graphene in epoxy resin and a thermally conductive network by graphene and Ni foam was formed in epoxy resin.By adding graphene-nickel three-dimensional filler into epoxy resin,the thermal conductivity of graphene-nickel/epoxy composite can reach up to 2.6549 W⋅m^(-1)⋅k^(-1),which was 9 times higher than that of raw epoxy resin.

Preparation of Core/Shell Electrically Conductive Fibers by Efficient Coating Carbon Nanotubes on Polyester

Conducting fibers with improved properties and functionalities are needed for diverse applications.Here we report the fabrica-tion of core/shell conductive Dacron fibers by dip-coating method through originating from multi-walled carbon nanotubes(MWCNTs)coated on polyester fibers.The annealing process was conducted to enhance interaction between the conductive shell and polyester core as well as within the MWCNTs network.The properties of two kinds of MWCNTs dispersions and the electrical properties of conductive fibers were studied,respectively.The results show that both MWCNTs-polyurethane resin(MWCNTs-WPU)dispersion and MWCNTs-acrylic resin(MWCNTs-PAA)dispersion present a typical characteristic of pseudo-plastic fluid and an excellent wetting ability to polyester fibers.The ultimate tensile stress and elongation at break for the MWCNTs-PAA coated fiber are 261 MPa and 25.43%.The ultimate tensile stress and the elongation at break are both increasing with the increasing of MWCNTs contents,due to the strong interface bonding ability between the conduc-tive shell and polyester core and strengthen the MWCNTs network.The electrical resistance of the obtained fibers can be controlled in the range from 732 to 30Ω/cm by changing MWCNTs content,dipping times and annealing temperature.It was found that it is able to light a LED.All results suggest that the conductive fibers embody a good synergy effect of carbon nanotubes and polymers.Therefore,the fabricated conductive fibers have a widely prospect for being applied in the field of flexible electronics.

Molecular level understanding of CO_(2) capture in ionic liquid/polyimide composite membrane

Ionic liquid(IL)/polyimide(PI)composite membranes demonstrate promise for use in CO_(2)separation applications.However,few studies have focused on the microscopic mechanism of CO_(2)in these composite systems,which is important information for designing new membranes.In this work,a series of systems of CO_(2)in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide composited with 4,4-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)-based PI,6FDA-2,3,5,6-tetramethyl-1,4-phenylene-diamine,at different IL concentrations were investigated by all-atom molecular dynamics simulation.The formation of IL regions in PI was found,and the IL regions gradually became continuous channels with increasing IL concentrations.The analysis of the radial distribution functions and hydrogen bond numbers demonstrated that PI had a stronger interaction with cations than anions.However,the hydrogen bonds among PI chains were destroyed by the addition of IL,which was favorable for transporting CO_(2).Furthermore,the self-diffusion coefficient and free energy barrier suggested that the diffusion coefficient of CO_(2)decreased with increasing IL concentrations up to 35 wt-%due to the decrease of the fractional free volume of the composite membrane.However,the CO_(2)selfdiffusion coefficients increased when the IL contents were higher than 35 wt-%,which was attributed to the formation of continuous IL domain that benefitted the transportation of CO_(2).

Ionic-microenvironment stabilizes the disulfide engineered lysine decarboxylase for efficient cadaverine production

Cadaverine is the key monomer for the synthesis of nylon 5X.Efficient and alkaline stable lysine decarboxylases are highly desirable for cadaverine production as the reaction pH increasing from 6.3 to 8.5.However,the most studied lysine decarboxylase CadA(E.coli)lost almost all activity at pH 8.0,which is the foremost challenge for the industrial-cadaverine production.In this study,we first found that the Na^(+)-microenvironment significantly improved the alkaline stability of the disulfide engineered lysine decarboxylaseΔLdcEt3(P233C/L628C)(half-life 362 h),compared to the conventional buffer(half-life 0.66 h)at pH 8.0.Meanwhile,the whole-cell conversion efficiency of the industrial-grade L-lysine withΔLdcEt3 could reach up to 99%in 2 h in the fermenter.Experi-mental investigation and molecular dynamics confirmed that Na^(+)-microenvironment could improve active-aggregation state and affect secondary structure ofΔLdcEt3.Therefore,Na^(+)-microenvironment stabilizesΔLdcEt3 providing a great potential industrial application for high-level cadaverine production.

Highly bonded T-Nb2O5/rGO nanohybrids for 4 V quasisolid state asymmetric supercapacitors with improved electrochemical performance

Orthorhombic niobium pentoxide （T-Nb2O5）/reduced graphene oxide nanohybrids were fabricated via the hydrothermal attachment of Nb2Os nanowires to dispersed graphene oxide nanosheets followed by a high-temperature phase transformation. Electrochemical measurements showed that the nanohybrid anodes possessed enhanced reversible capacity and superior cycling stability compared to those of a pristine T-Nb205 nanowire electrode. Owing to the strong bonds between graphene nanosheets and T-Nb2O5 nanowires, the nanohybrids achieved an initial capacity of 227 mAh·g^-1. Additionally, non-aqueous asymmetric supercapacitors （ASCs） were fabricated with the synthesized nanohybrids as the anode and activated carbon as the cathode. The 3 V Li-ion ASC with a LiPF6-based organic electrolyte achieved an energy density of 45.1 Wh·kg^-1 at 715.2 W·kg^-1. The working potential could be further enhanced to 4 V when a polymer ionogel separator （PVDF-HFP/LiTFSI/EMIMBF4） and formulated ionic liquid electrolyte were employed. Such a quasi-solid state ASC could operate at 60℃ and delivered a maximum energy density of 70 Wh·kg^-1 at 1 kW·kg^-1.

Pure organic room-temperature phosphorescent N-allylquinolinium salts as anti-counterfeiting materials

Pure organic room-temperature phosphorescence (RTP) materials have been attracting much attention recently. Herein, we report a facile approach combining heavy atom effect and external solvent stimuli to realize RTP. N-Allylquinolinium bromide under 365 nm UV exhibited intense green RTP emission with response upon adding chloroform. This interesting phenomenon endowed N-allylquinolinium bromide great potential as an anti-counterfeiting material.

溶剂化能调控实现低浓度锂电池电解液

锂离子的溶剂化结构对电极/电解液的界面性能有决定性的作用,进而影响电池性能.降低盐浓度可能导致固态电解质界面(SEI)膜中有机组分含量增加、进而影响循环稳定性,这使得发展低浓度电解液(LCEs)非常具有挑战性.低溶剂化能溶剂与盐之间的弱相互作用给LCEs带来了新的机会.本文采用氟代碳酸乙烯酯(FEC)和1,1,2,2-四氟乙基-2,2,3,3-四氟丙基醚(D_(2))制备了盐浓度仅为0.25mol L^(-1)的LCE.分子动力学模拟和实验证明,溶剂化能较低的FEC不仅降低了Li^(+)的去溶剂化能、改善了电池动力学,而且促进了富含LiF的SEI的形成、抑制了电解液的消耗.使用LCE的Li||Cu电池库仑效率高达99.20%,LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)||Li电池在200个循环中也表现出89.93%的容量保留率,这表明溶剂化能调控在LCEs发展中有巨大潜力.