Considerable progress has been made in recent years to the development of sustainable polymers from bio-based feedstocks.In this study,100%bio-based nylons were prepared via an integrated chemical and biological proce...Considerable progress has been made in recent years to the development of sustainable polymers from bio-based feedstocks.In this study,100%bio-based nylons were prepared via an integrated chemical and biological process from lignocellulose.These novel nylons were obtained by the melt polymerization of 3-propyladipic acid derived from lignin and 1,5-pentenediamine/1,4-butanediamine derived from carbohydrate sugar.Central to the concept is a three-step noble metal free catalytic chemical funnelling sequence(Raney Ni mediated reductive catalytic fractionation-reductive funnelling-oxidative funnelling),which allowed for obtaining a single component 3-propyladipic acid from lignin with high efficiency.The structural and thermodynamic properties of the obtained nylons have been systematically investigated,and thus obtained transparent bio-based nylons exhibited higher Mw(>32,000)and excellent thermal stability(Td5%>265℃).Considering their moderate Tg and good melt strength,these transparent bio-based nylons could serve as promising functional additives or temperature-responsive materials.展开更多
All-solid-state lithium metal batteries(ASSLMBs)are considered as one of the ultimate goals for the development of energy storage systems due to their high energy density and high safety.However,the mismatching of int...All-solid-state lithium metal batteries(ASSLMBs)are considered as one of the ultimate goals for the development of energy storage systems due to their high energy density and high safety.However,the mismatching of interface transport kinetics as well as interfacial instability induces the growth of lithium dendrite and thus,leads to severe degradation of battery electrochemical performances.Herein,an integrated interface configuration(IIC)consisting of in-situ generated Li I interphase and Li-Ag alloy anode is proposed through in-situ interface chemistry.The IIC is capable of not only regulating charge transport kinetics but also synchronously stabilizing the lithium/electrolyte interface,thereby achieving uniform lithium platting.Therefore,Li||Li symmetric cells with IIC achieve a critical current density of up to 1.6 mA cm^(-2)and achieve stable cycling over 1600 hours at a high current density of 0.5 mA cm^(-2).Moreover,a high discharge capacity of 140.1 mA h g-1at 0.1 C is also obtained for the Li(Ni_(0.6)Co_(0.2)Mn_(0.2))O_(2)(NCM622)full battery with a capacity retention of 65.6%after 300 cycles.This work provides an effective method to synergistically regulate the interface transport kinetics and inhibit lithium dendrite growth for high-performance ASSLMBs.展开更多
As the application of next-generation energy storage systems continues to expand,rechargeable secondary batteries with enhanced energy density and safety are imperative for energy iteration.Sodium-ion batteries(SIBs)h...As the application of next-generation energy storage systems continues to expand,rechargeable secondary batteries with enhanced energy density and safety are imperative for energy iteration.Sodium-ion batteries(SIBs)have attracted extensive attention and are recognized as ideal candidates for large-scale energy storage due to the abundant sodium resources and low cost.Sodium metal anodes(SMAs)have been considered as one of the most attractive anode materials for SIBs owing to their high specific capacity(1166 mAh g^(-1)),low redox potential,and abundant natural resources.However,the uncontrollable dendrite growth and inevitable side reactions on SMA lead to the continuous deterioration of the electrochemical performance,causing serious safety concerns and limiting their practical application in the future.Therefore,the construction of stable dendrite-free SMAs is a pressing problem for advanced sodium metal batteries(SMBs).In this review,we comprehensively summarize the research progress in suppressing the formation of sodium dendrite,including artificial solid electrolyte interphase(SEI),liquid electrolyte modification,three-dimensional(3D)host materials,and solid-state electrolyte.Additionally,key aspects and prospects of future research directions for SMAs are highlighted.We hope that this timely review can provide an overall picture of sodium protection strategies and stimulate more research in the future.展开更多
Bimolecular interactions play crucial roles in lignin pyrolysis.The tautomerization of key intermediates has a significant impact on the formation of stable products,whereas bimolecular tautomerization has been rarely...Bimolecular interactions play crucial roles in lignin pyrolysis.The tautomerization of key intermediates has a significant impact on the formation of stable products,whereas bimolecular tautomerization has been rarely clarified.In the present work,the bimolecular tautomerization mechanism induced by both concerted and radical interactions was proposed and carefully confirmed.A characteristicβ-O-4 lignin dimer,2-phenoxy-1-phenylethanol(α-OH-PPE),was used as the model compound to reveal two representative keto-phenol and enol-keto tautomerism mechanisms,based on theoretical calculations combined with pyrolysis experiments.The results indicate that the unimolecular tautomerism as the rate-determining step limits product generation,due to fairly high energy barriers.While the free hydroxy compounds and radicals derived from initial pyrolysis can further initiate bimolecular tautomerism reactions through the one-step concerted hydroxyl-assisted hydrogen transfer(hydroxylAHT)and two-step radical hydrogen abstraction interactions,respectively.By alleviating and even avoiding the large ring tension of tautomerism,the unstable tautomers(2,4-cyclohexadienone and1-hydroxy styrene)can be rapidly tautomerized into stable phenol and acetophenone with the help of intermolecular interaction.Benefitting from the significant advantage of retro-ene fragmentation in breaking theβ-O-4 bond to form tautomers,a large amount of stable phenolic and ketone products can be generated following bimolecular tautomerization in the pyrolysis ofβ-O-4 linked lignin.展开更多
Lignin waste from the papermaking and biorefineries industry is a significantly promising renewable resource to prepare advanced carbon materials for diverse applications,such as the electrodes of supercapacitors;howe...Lignin waste from the papermaking and biorefineries industry is a significantly promising renewable resource to prepare advanced carbon materials for diverse applications,such as the electrodes of supercapacitors;however,the improvement of their energy density remains a challenge.Here,we design a green and universal approach to prepare the composite electrode material,which is composed of lignin-phenolformaldehyde resins derived hierarchical porous carbon(LR-HPC)as conductive skeletons and the self-assembly manganese cobaltite(MnCo_(2)O_(4))nanocrystals as active sites.The synthesized C@MnCo_(2)O_(4)composite has an abundant porous structure and superior electronic conductivity,allowing for more charge/electron mass transfer channels and active sites for the redox reactions.The composite shows excellent electrochemical performance,such as the maximum specific capacitance of~726 mF cm^(-2)at 0.5 mV s^(-1),due to the significantly enhanced interactive interface between LR-HPC and MnCo_(2)O_(4)crystals.The assembled all-solid-state asymmetric supercapacitor,with the LR-HPC and C@MnCo_(2)O_(4)as cathode and anode,respectively,exhibits the highest volumetric energy density of 0.68 mWh cm^(-3)at a power density of 8.2 mW cm^(-3).Moreover,this device shows a high capacity retention ratio of~87.6%at 5 mA cm^(-2)after 5000 cycles.展开更多
To attain the objectives of carbon peaking and carbon neutrality,the development of stable and highperformance ion-conducting materials holds enormous relevance in various energy storage and conversion devices.Particu...To attain the objectives of carbon peaking and carbon neutrality,the development of stable and highperformance ion-conducting materials holds enormous relevance in various energy storage and conversion devices.Particularly,crystalline porous materials possessing built-in ordered nanochannels exhibit remarkable superiority in comprehending the ion transfer mechanisms with precision.In this regard,covalent organic frameworks(COFs)are highly regarded as a promising alternative due to their preeminent structural tunability,accessible well-defined pores,and excellent thermal/chemical stability under hydrous/anhydrous conditions.By the availability of organic units and the diversity of topologies and connections,advances in COFs have been increasing rapidly over the last decade and they have emerged as a new field of proton-conducting materials.Therefore,a comprehensive summary and discussion are urgently needed to provide an"at a glance"understanding of the prospects and challenges in the development of proton-conducting COFs.In this review,we target a comprehensive review of COFs in the field of proton conductivity from the aspects of design strategies,the proton conducting mechanism/features,the relationships of structure-function,and the application of research.The relevant content of theoretical simulation,advanced structural characterizations,prospects,and challenges are also presented elaborately and critically.More importantly,we sincerely hope that this progress report will form a consistent view of this field and provide inspiration for future research.展开更多
Transformation of lignin to valuable chemicals via sustainable pathways is recognized as one of the most efficient ways to explore its value and replace the nonrenewable petroleum resource. In this work, an environmen...Transformation of lignin to valuable chemicals via sustainable pathways is recognized as one of the most efficient ways to explore its value and replace the nonrenewable petroleum resource. In this work, an environmental-friendly transfer hydrogenation process has been developed to convert lignin derived2,6-dimethoxybenzoquinone to 1,4-cyclohexanediol. Compared with previous work under hydrogen pressure(30 bar), this process uses isopropanol as both solvent and hydrogen donor, which significantly simply the operation process. The core of this study is the design and preparation of Mn modified Raney Ni catalysts by ball milling process. A series of Raney Ni Mn catalysts with different ball milling time and Mn content were prepared and investigated. Characterizations by X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electron microscope(SEM) and transmission electron microscope(TEM) etc. showed that Ni Mn Al alloy was formed during the ball milling process and then transformed to Ni Mn alloy after treatment by aqueous Na OH. After optimization, a yield as high as 86.1% could be achieved for 1,4-cyclohexanediol at 200℃ in only 1 h.展开更多
As the rapid development of portable and wearable devices,different electromagnetic interference(EMI)shielding materials with high efficiency have been desired to eliminate the resulting radiation pollution.However,li...As the rapid development of portable and wearable devices,different electromagnetic interference(EMI)shielding materials with high efficiency have been desired to eliminate the resulting radiation pollution.However,limited EMI shielding materials are successfully used in practical applications,due to the heavy thickness and absence of sufficient strength or flexibility.Herein,an ultrathin and flexible carbon nanotubes/MXene/cellulose nanofibrils composite paper with gradient and sandwich structure is constructed for EMI shielding application via a facile alternating vacuum-assisted filtration process.The composite paper exhibits outstanding mechanical properties with a tensile strength of 97.9±5.0 MPa and a fracture strain of 4.6±0.2%.Particularly,the paper shows a high electrical conductivity of 2506.6 S m?1 and EMI shielding effectiveness(EMI SE)of 38.4 dB due to the sandwich structure in improving EMI SE,and the gradient structure on regulating the contributions from reflection and absorption.This strategy is of great significance in fabricating ultrathin and flexible composite paper for highly efficient EMI shielding performance and in broadening the practical applications of MXene-based composite materials.展开更多
The aim of this study was to investigate the hemicelluloses extracted from Populus tomentosa Carr.by the hydrothermal method with ethanol.The influence of ethanol concentration on the hemicellulosic fractions was syst...The aim of this study was to investigate the hemicelluloses extracted from Populus tomentosa Carr.by the hydrothermal method with ethanol.The influence of ethanol concentration on the hemicellulosic fractions was systematically studied.The chemical compositions and structural features of the hemicellulosic fractions were investigated by a combination of sugar analysis,gel-permeation chromatography,Fourier transform infrared spectroscopy,and one-dimensional proton and carbon-13 nuclear magnetic resonance,and two-dimensional heteronuclear single quantum coherence spectroscopy.Neutral sugar analysis of the hemicellulosic fractions revealed that a higher ethanol concentration(45%~80%) favored the isolation of hemicelluloses with more side chains and lower glucose contents.The molecular weights of these polysaccharides ranged between 2842 g/mol and 5101 g/mol.The results of this study indicate that the hydrothermal ethanol process provides a new pretreatment strategy for the isolation and extraction of biomass.展开更多
Lithium(Li)metal is regarded as a promising anode material to render the Li batteries with high energy density and therefore satisfy the ever-growing energy demands of high-end storage devices[1].Unfortunately,the den...Lithium(Li)metal is regarded as a promising anode material to render the Li batteries with high energy density and therefore satisfy the ever-growing energy demands of high-end storage devices[1].Unfortunately,the dendrite growth accompanied with accumulation of"dead Li"leads to low Coulombic efficiency,poor cycling lifespan,and even severe safety hazards,critically hindering the practical implementation of Li metal batteries[2,3].展开更多
The purpose of this study was to explore the differences of the hemicelluloses extracted by hydrothermal pretreatment using water and alkaline solutions(Na OH or KOH). The physicochemical properties and structural cha...The purpose of this study was to explore the differences of the hemicelluloses extracted by hydrothermal pretreatment using water and alkaline solutions(Na OH or KOH). The physicochemical properties and structural characteristics of two water-soluble and four alkali-soluble hemicelluloses extracted from the triploid of Populus tomentosa Carr. through the hydrothermal pretreatment were comparatively studied. It was observed that the alkalis(Na OH and KOH) were more effective than distilled water as extractants. Sugar analysis showed that xylose(66.83%~86.49%) was the major constituent, followed by glucose(6.83%~18.49%). Mannose(1.40%~8.42%), galactose(2.17%~4.05%), and arabinose(0.21%~2.26%) were also detected in the hemicellulosic fractions. The results of gelpermeation chromatography(GPC) indicated that the hemicelluloses extracted using the alkaline solutions had relatively higher molecular weights than those solubilized in distilled water. Further, based on spectroscopic ~1Hnuclear magnetic resonance(~1H-NMR) and two-dimensional heteronuclear singular quantum correlation(2D-HSQC) analyses, it was confirmed that the hemicellulosic fractions had a major structure of(1→4)-b-D-xylan and a minor structure of(1→4)-a-D-glucan with small amounts of substituted sugars and glucuronic acid attached.展开更多
The aromatic nature of lignin makes it a potential renewable source of chemicals and other valuable products.Isolation of lignin from lignocellulosic biomass using organic solvents enables the production of high-purit...The aromatic nature of lignin makes it a potential renewable source of chemicals and other valuable products.Isolation of lignin from lignocellulosic biomass using organic solvents enables the production of high-purity lignin.The use of formic acid in the organosolv pulping and fractionation process has been widely studied.Characterization of lignin is necessary to achieve valueadded applications of lignin.To simplify the isolation of formic acid-treated lignin,herein,milled wheat straw lignin(MWSL) was employed as an archetype for characterization of the structural changes of lignin during formic acid treatment.The results showed that the MWSL was GSH-type(comprising p-hydroxyphenyl(H),guaiacyl(G),and syringyl(S) monolignols) and underwent structural changes during formic acid treatment.Lignin was esterified during the formic acid treatment.The content of alkyl hydroxyl groups in lignin decreased upon formic acid treatment,corresponding to an increase of the number of double bond equivalents(DBE).Lignin units with active reaction sites were liable to slight condensation,which resulted in a moderate increase of the molecular weight.The molecular weight distribution of formic acid-treated MWSL(FMWSL) was wider than that of the MWSL,although the molecular weight of both species did not differ significantly.The β-O-4 linkage in lignin was partially cleaved during formic acid treatment,resulting in the production of new phenolic structures.This improved the solubility of lignin in the cooking liquor and its reactivity for downstream applications.展开更多
In this article, a facile two-step activation method, coupled with phosphoric acid(H3PO4)-assisted pretreatment and followed KOH activation,was reported for constructing hierarchical porous carbon(HPC) materials deriv...In this article, a facile two-step activation method, coupled with phosphoric acid(H3PO4)-assisted pretreatment and followed KOH activation,was reported for constructing hierarchical porous carbon(HPC) materials derived from lignin. The introduction of H3PO4, cross-linked with lignin sources generated phosphate(and/or polyphosphate) ester groups throughout the lignin structure, which endowed the pre-activated intermediate char(IC)with a hierarchical porous structure. Such phosphate esters contributed to the multi-scale pore structure within the pre-activated IC, which was beneficial for the uniform distribution and impregnation of subsequent KOH activators,thus leading to the formation of HPC materials. The as-prepared HPC exhibited a large specific surface area(SSA) of 1345.1 m^2/g, which ensures the accessibility of the ion diffusion pathways. The supercapacitors integrated with HPC delivered a high specific capacitance of 241 F/g(in a threeelectrode system) and outstanding rate capability with an 80.9% capacitance retention from 0.5 A/g to an ultra-high current density of 50 A/g.展开更多
Peroxidase plays an important role in living systems;however,its storage difficulty and easy inactivation have limited its applications in complex environments.To address these problems,herein,we proposed a method to ...Peroxidase plays an important role in living systems;however,its storage difficulty and easy inactivation have limited its applications in complex environments.To address these problems,herein,we proposed a method to synthesize peroxidase mimics by amination,carbonization,and Fe^(3+)-doping of industrial alkali lignin.The Fe^(3+)-doped lignin-based peroxidase mimic(Fe-LPM),with active centers of coordination between Fe^(3+)and N atoms,showed higher tolerance to pH value and temperature than natural peroxidase.Using Fe-LPM,10-100 mmol/L of H_(2)O_(2) and glucose could be colorimetrically detected with the lowest detection limits of 80μmol/L and 1.5 mmol/L and visual detection limits of 1.0 mmol/L and 10 mmol/L,respectively.The Fe-LPM maintained peroxidase-like activity after 10 cycles and could even be used for H_(2)O_(2) detection in practical samples.This work not only provides a new approach to synthesize peroxidase mimics using biomass materials but also promotes the high-value utilization of lignin.展开更多
In this study,xylan-based double-network(DN)hydrogels(xylanbased DN gels)with excellent mechanical properties were prepared using acrylic acid and acrylamide(AM)based on a DN approach.The first layer network was obtai...In this study,xylan-based double-network(DN)hydrogels(xylanbased DN gels)with excellent mechanical properties were prepared using acrylic acid and acrylamide(AM)based on a DN approach.The first layer network was obtained by grafting and crosslinking polyacrylic acid(PAA)molecular chains onto xylan with ammonium persulfate(APS)as the initiator and N,N'-methylenebisacrylamide(MBA)as the crosslinking agent;this network was subsequently immersed into an aqueous AM monomer in the presence of APS and MBA for the preparation of the second layer network.The results showed that the double networks were crosslinked by covalent bonds and that the mechanical properties of the xylan-based DN gels were enhanced.Thus,the xylan-based DN gels exhibited a maximum compression stress of 24.9 MPa.The xylan-based DN gels could also recover 97%of their original height after 15 repeated compression cycles;this indicates that the xylan-based DN gels possessed high resistance to friction and wear.Therefore,the prepared xylan-based DN gels have considerable potential for tissue engineering applications.展开更多
The conversion of lignocellulose to value-added products is normally focused on fuel production;however,large-scale biorefineries require a cost-effective pretreatment process that can effectively fractionate the thre...The conversion of lignocellulose to value-added products is normally focused on fuel production;however,large-scale biorefineries require a cost-effective pretreatment process that can effectively fractionate the three main constituents of lignocellulose for the production of chemicals,fuels,and materials.In this study,a hemicellulosic biopolymer from poplar was fractionated by a mild organosolv process and the effects of various chemicals(sodium hydroxide,triethylamine,and formic acid)and alcohols on the fractionation efficiency and structural variation of hemicellulose were examined.Comparative studies indicated that an acidic catalyst decreased the purity of hemicelluloses by partial degradation of cellulose,and the core of the hemicellulosic biomacromolecule could be released and dissolved under alkaline conditions with 5.8%~19.0%yields.In addition,the use of alcohol with longer alkyl chains facilitated the release of the hemicellulosic biomacromolecule by partially cleaving the ether bonds in the lignincarbohydrate complex(LCC);this is probably due to steric hindrance.The thermal degradation behavior showed that complete pyrolysis was easily achieved for the hemicellulosic polymer with minimal branches irrespective of its molecular weight.展开更多
Wood-based hydrogel with a unique anisotropic structure is an attractive soft material,but the presence of rigid crystalline cellulose in natural wood makes the hydrogel less flexible.In this study,an all-wood hydroge...Wood-based hydrogel with a unique anisotropic structure is an attractive soft material,but the presence of rigid crystalline cellulose in natural wood makes the hydrogel less flexible.In this study,an all-wood hydrogel was constructed by cross-linking cellulose fibers,polyvinyl alcohol(PVA)chains,and lignin molecules through the Hofmeister effect.The all-wood hydrogel shows a high tensile strength of 36.5 MPa and a strain up to~438%in the longitudinal direction,which is much higher than its tensile strength(~2.6 MPa)and strain(~198%)in the radial direction,respectively.The high mechanical strength of all-wood hydrogels is mainly attributed to the strong hydrogen bonding,physical entanglement,and van der Waals forces between lignin molecules,cellulose nanofibers,and PVA chains.Thanks to its excellent flexibility,good conductivity,and sensitivity,the all-wood hydrogel can accurately distinguish diverse macroscale or subtle human movements,including finger flexion,pulse,and swallowing behavior.In particular,when“An Qi”was called four times within 15 s,two variations of the pronunciation could be identified.With recyclable,biodegradable,and adjustable mechanical properties,the all-wood hydrogel is a multifunctional soft material with promising applications,such as human motion monitoring,tissue engineering,and robotics materials.展开更多
With the world’s fossil fuels being finite in nature,an increasing interest focuses on the application of alternative renewable resources such as biomass.Biomass-derived platform chemicals with abundant functional gr...With the world’s fossil fuels being finite in nature,an increasing interest focuses on the application of alternative renewable resources such as biomass.Biomass-derived platform chemicals with abundant functional groups have the potential to replace bulk chemicals for the production of value-added chemicals,fuels,and materials.The upgrading of these platform chemicals relies on the development of efficient catalytic systems.Hydrotalcite,with its wide compositional variety,tuneable anion-exchange capacity,and controlled acidity/basicity sites demonstrates great potential in the catalytic upgrading of biomass and the derived platform chemicals.The past decade has witnessed the emergence of research achievements on the development of efficient and robust hydrotalcite-derived metal catalysts and their applications in the upgrading of biomass or the derived platform chemicals.In this review,we aim to summarize the recent advances on the catalytic upgrading of biomass-derived platform chemicals(e.g.,furfural,5-hydroxymethylfurfural,levulinic acid,and glycerol)via hydrotalcitederived metal catalysts.We also observed that the crucial role of using hydrotalcite-derived catalysts relies on their strong metal–support interactions.As a result,a section focusing on the discussion of the metal–support interactions of hydrotalcitederived catalysts was provided.展开更多
The rheological characteristics of a physical gelation system,in which cellulose nanocrystals(CNC_(s))induced the entanglement of poly(acrylic acid)(PAA)chains and partial hydrophobic association of octylphenol polyox...The rheological characteristics of a physical gelation system,in which cellulose nanocrystals(CNC_(s))induced the entanglement of poly(acrylic acid)(PAA)chains and partial hydrophobic association of octylphenol polyoxyethylene acrylate(OP-10-AC)branches in a micellar solution of sodium dodecyl sulfate(SDS),were investigated.The gelation time of the physical gels decreased as the CNC content and number of hydrophobic branch units increased.At the gel point,the storage modulus(G')and loss modulus(G")followed the same frequency dependence(G'≈G"≈ωn),where the hydrophobic moieties attached to the side chains had a significant impact on the values of viscoelastic exponent(n).Beyond the gel point,the initial polymer solution was transformed to a solid-like gel,and the strength of the gel network was governed by associations between both the CNCs and hydrophobic groups.The evolution of the viscoelasticity during the gel-sol transition was monitored,demonstrating that due to a reversible arrangement of the hydrophobic units,a large proportion of physical cross-links dissociated under a thermal trigger and were reversibly reformed when the solution was cooled,while no such partial recovery was observed in the case of the single CNC-induced network systems(with no hydrophobic branches).展开更多
Two-dimensional(2 D) graphene oxide(GO) nanosheets and 1 D2,2,6,6-tetramethylpiperidin-1-oxyl(TEMPO)-oxidized cellulose nanofibers(TOCN) were assembled into GO/TOCN aerogels via a low temperature hydrothermal and free...Two-dimensional(2 D) graphene oxide(GO) nanosheets and 1 D2,2,6,6-tetramethylpiperidin-1-oxyl(TEMPO)-oxidized cellulose nanofibers(TOCN) were assembled into GO/TOCN aerogels via a low temperature hydrothermal and freeze-drying process. The as-prepared GO/TOCN aerogels exhibited interconnected 3 D network microstructures, a low density of 6.8 mg/cm^3, a high porosity up to 99.2% and excellent mechanical flexibility.The high porosity in conjunction with their hydrophobicity(contact angle of 121.5°), allowed the aerogels to absorb different organic liquids with absorption capacities up to 240 times of their own weight, depending on the density of the liquids. These results indicated that the aerogels were excellent candidates as sorbent materials for the clean-up of organic liquids. After five absorption-desorption cycles, the absorption capacity of the TOCN carbon aerogels could be regenerated up to 97% of the initial absorption capability,which demonstrated their excellent recyclability.展开更多
基金support by National Key Research and Development Program of China(Grant No.:2023YFA0913604)Program of National Natural Science Foundation of China(Grant No.:22178170,22378195)+2 种基金Six talent peaks project in Jiangsu Province(SWYY-045)Program of National Natural Science Foundation of China(Grant No.22208155)Jiangsu Province Natural Science Foundation for Young Scholars(Grant No.BK20210552).
文摘Considerable progress has been made in recent years to the development of sustainable polymers from bio-based feedstocks.In this study,100%bio-based nylons were prepared via an integrated chemical and biological process from lignocellulose.These novel nylons were obtained by the melt polymerization of 3-propyladipic acid derived from lignin and 1,5-pentenediamine/1,4-butanediamine derived from carbohydrate sugar.Central to the concept is a three-step noble metal free catalytic chemical funnelling sequence(Raney Ni mediated reductive catalytic fractionation-reductive funnelling-oxidative funnelling),which allowed for obtaining a single component 3-propyladipic acid from lignin with high efficiency.The structural and thermodynamic properties of the obtained nylons have been systematically investigated,and thus obtained transparent bio-based nylons exhibited higher Mw(>32,000)and excellent thermal stability(Td5%>265℃).Considering their moderate Tg and good melt strength,these transparent bio-based nylons could serve as promising functional additives or temperature-responsive materials.
基金supported by the Beijing Natural Science Foundation(L223009)the National Natural Science Foundation of China(22075029)+1 种基金the National Key Research and Development Program of China(2021YFB2500300)the Key Research and Development(R&D)Projects of Shanxi Province(2021020660301013)。
文摘All-solid-state lithium metal batteries(ASSLMBs)are considered as one of the ultimate goals for the development of energy storage systems due to their high energy density and high safety.However,the mismatching of interface transport kinetics as well as interfacial instability induces the growth of lithium dendrite and thus,leads to severe degradation of battery electrochemical performances.Herein,an integrated interface configuration(IIC)consisting of in-situ generated Li I interphase and Li-Ag alloy anode is proposed through in-situ interface chemistry.The IIC is capable of not only regulating charge transport kinetics but also synchronously stabilizing the lithium/electrolyte interface,thereby achieving uniform lithium platting.Therefore,Li||Li symmetric cells with IIC achieve a critical current density of up to 1.6 mA cm^(-2)and achieve stable cycling over 1600 hours at a high current density of 0.5 mA cm^(-2).Moreover,a high discharge capacity of 140.1 mA h g-1at 0.1 C is also obtained for the Li(Ni_(0.6)Co_(0.2)Mn_(0.2))O_(2)(NCM622)full battery with a capacity retention of 65.6%after 300 cycles.This work provides an effective method to synergistically regulate the interface transport kinetics and inhibit lithium dendrite growth for high-performance ASSLMBs.
基金This study was supported by Beijing Natural Science Foundation(No.2202034)National Natural Science Foundation of China(No.21978024)the National Key R&D Program of China(No.2019YFB1309703)。
文摘As the application of next-generation energy storage systems continues to expand,rechargeable secondary batteries with enhanced energy density and safety are imperative for energy iteration.Sodium-ion batteries(SIBs)have attracted extensive attention and are recognized as ideal candidates for large-scale energy storage due to the abundant sodium resources and low cost.Sodium metal anodes(SMAs)have been considered as one of the most attractive anode materials for SIBs owing to their high specific capacity(1166 mAh g^(-1)),low redox potential,and abundant natural resources.However,the uncontrollable dendrite growth and inevitable side reactions on SMA lead to the continuous deterioration of the electrochemical performance,causing serious safety concerns and limiting their practical application in the future.Therefore,the construction of stable dendrite-free SMAs is a pressing problem for advanced sodium metal batteries(SMBs).In this review,we comprehensively summarize the research progress in suppressing the formation of sodium dendrite,including artificial solid electrolyte interphase(SEI),liquid electrolyte modification,three-dimensional(3D)host materials,and solid-state electrolyte.Additionally,key aspects and prospects of future research directions for SMAs are highlighted.We hope that this timely review can provide an overall picture of sodium protection strategies and stimulate more research in the future.
基金the National Natural Science Foundation of China(52276189,52106241)Natural Science Foundation of Jiangsu Province(BK20221248)for financial support。
文摘Bimolecular interactions play crucial roles in lignin pyrolysis.The tautomerization of key intermediates has a significant impact on the formation of stable products,whereas bimolecular tautomerization has been rarely clarified.In the present work,the bimolecular tautomerization mechanism induced by both concerted and radical interactions was proposed and carefully confirmed.A characteristicβ-O-4 lignin dimer,2-phenoxy-1-phenylethanol(α-OH-PPE),was used as the model compound to reveal two representative keto-phenol and enol-keto tautomerism mechanisms,based on theoretical calculations combined with pyrolysis experiments.The results indicate that the unimolecular tautomerism as the rate-determining step limits product generation,due to fairly high energy barriers.While the free hydroxy compounds and radicals derived from initial pyrolysis can further initiate bimolecular tautomerism reactions through the one-step concerted hydroxyl-assisted hydrogen transfer(hydroxylAHT)and two-step radical hydrogen abstraction interactions,respectively.By alleviating and even avoiding the large ring tension of tautomerism,the unstable tautomers(2,4-cyclohexadienone and1-hydroxy styrene)can be rapidly tautomerized into stable phenol and acetophenone with the help of intermolecular interaction.Benefitting from the significant advantage of retro-ene fragmentation in breaking theβ-O-4 bond to form tautomers,a large amount of stable phenolic and ketone products can be generated following bimolecular tautomerization in the pyrolysis ofβ-O-4 linked lignin.
基金The authors gratefully acknowledge the financial support from the National Key R&D Program of China(2021YFC2101304)China Postdoctoral Science Foundation(BX2021041)。
文摘Lignin waste from the papermaking and biorefineries industry is a significantly promising renewable resource to prepare advanced carbon materials for diverse applications,such as the electrodes of supercapacitors;however,the improvement of their energy density remains a challenge.Here,we design a green and universal approach to prepare the composite electrode material,which is composed of lignin-phenolformaldehyde resins derived hierarchical porous carbon(LR-HPC)as conductive skeletons and the self-assembly manganese cobaltite(MnCo_(2)O_(4))nanocrystals as active sites.The synthesized C@MnCo_(2)O_(4)composite has an abundant porous structure and superior electronic conductivity,allowing for more charge/electron mass transfer channels and active sites for the redox reactions.The composite shows excellent electrochemical performance,such as the maximum specific capacitance of~726 mF cm^(-2)at 0.5 mV s^(-1),due to the significantly enhanced interactive interface between LR-HPC and MnCo_(2)O_(4)crystals.The assembled all-solid-state asymmetric supercapacitor,with the LR-HPC and C@MnCo_(2)O_(4)as cathode and anode,respectively,exhibits the highest volumetric energy density of 0.68 mWh cm^(-3)at a power density of 8.2 mW cm^(-3).Moreover,this device shows a high capacity retention ratio of~87.6%at 5 mA cm^(-2)after 5000 cycles.
基金financial support from the National Natural Science Foundation of China(21978024)the Beijing Natural Science Foundation(2202034)。
文摘To attain the objectives of carbon peaking and carbon neutrality,the development of stable and highperformance ion-conducting materials holds enormous relevance in various energy storage and conversion devices.Particularly,crystalline porous materials possessing built-in ordered nanochannels exhibit remarkable superiority in comprehending the ion transfer mechanisms with precision.In this regard,covalent organic frameworks(COFs)are highly regarded as a promising alternative due to their preeminent structural tunability,accessible well-defined pores,and excellent thermal/chemical stability under hydrous/anhydrous conditions.By the availability of organic units and the diversity of topologies and connections,advances in COFs have been increasing rapidly over the last decade and they have emerged as a new field of proton-conducting materials.Therefore,a comprehensive summary and discussion are urgently needed to provide an"at a glance"understanding of the prospects and challenges in the development of proton-conducting COFs.In this review,we target a comprehensive review of COFs in the field of proton conductivity from the aspects of design strategies,the proton conducting mechanism/features,the relationships of structure-function,and the application of research.The relevant content of theoretical simulation,advanced structural characterizations,prospects,and challenges are also presented elaborately and critically.More importantly,we sincerely hope that this progress report will form a consistent view of this field and provide inspiration for future research.
基金supported by the Fundamental Research Funds for the Central Universities (BLX202132)the Foreign expert program (G2022109001L)+1 种基金the Beijing Forestry University Outstanding Young Talent Cultivation Project (2019JQ03005)the Young Tip-top Talent Project of Science and Technology Innovation by National Forestry and Grassland Administration of China(2019132609)。
文摘Transformation of lignin to valuable chemicals via sustainable pathways is recognized as one of the most efficient ways to explore its value and replace the nonrenewable petroleum resource. In this work, an environmental-friendly transfer hydrogenation process has been developed to convert lignin derived2,6-dimethoxybenzoquinone to 1,4-cyclohexanediol. Compared with previous work under hydrogen pressure(30 bar), this process uses isopropanol as both solvent and hydrogen donor, which significantly simply the operation process. The core of this study is the design and preparation of Mn modified Raney Ni catalysts by ball milling process. A series of Raney Ni Mn catalysts with different ball milling time and Mn content were prepared and investigated. Characterizations by X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electron microscope(SEM) and transmission electron microscope(TEM) etc. showed that Ni Mn Al alloy was formed during the ball milling process and then transformed to Ni Mn alloy after treatment by aqueous Na OH. After optimization, a yield as high as 86.1% could be achieved for 1,4-cyclohexanediol at 200℃ in only 1 h.
基金financial support from the National Natural Science Foundation of China(31771081,51472259)the Science and Technology Commission of Shanghai Municipality(18ZR1445100)Beijing Forestry University Outstanding Young Talent Cultivation Project(2019JQ03014).
文摘As the rapid development of portable and wearable devices,different electromagnetic interference(EMI)shielding materials with high efficiency have been desired to eliminate the resulting radiation pollution.However,limited EMI shielding materials are successfully used in practical applications,due to the heavy thickness and absence of sufficient strength or flexibility.Herein,an ultrathin and flexible carbon nanotubes/MXene/cellulose nanofibrils composite paper with gradient and sandwich structure is constructed for EMI shielding application via a facile alternating vacuum-assisted filtration process.The composite paper exhibits outstanding mechanical properties with a tensile strength of 97.9±5.0 MPa and a fracture strain of 4.6±0.2%.Particularly,the paper shows a high electrical conductivity of 2506.6 S m?1 and EMI shielding effectiveness(EMI SE)of 38.4 dB due to the sandwich structure in improving EMI SE,and the gradient structure on regulating the contributions from reflection and absorption.This strategy is of great significance in fabricating ultrathin and flexible composite paper for highly efficient EMI shielding performance and in broadening the practical applications of MXene-based composite materials.
基金Financial support from the Foundation(No.KF201607)of the Key Laboratory of Pulp and Paper Science and Technology of the Ministry of Education/Shandong Province of China
文摘The aim of this study was to investigate the hemicelluloses extracted from Populus tomentosa Carr.by the hydrothermal method with ethanol.The influence of ethanol concentration on the hemicellulosic fractions was systematically studied.The chemical compositions and structural features of the hemicellulosic fractions were investigated by a combination of sugar analysis,gel-permeation chromatography,Fourier transform infrared spectroscopy,and one-dimensional proton and carbon-13 nuclear magnetic resonance,and two-dimensional heteronuclear single quantum coherence spectroscopy.Neutral sugar analysis of the hemicellulosic fractions revealed that a higher ethanol concentration(45%~80%) favored the isolation of hemicelluloses with more side chains and lower glucose contents.The molecular weights of these polysaccharides ranged between 2842 g/mol and 5101 g/mol.The results of this study indicate that the hydrothermal ethanol process provides a new pretreatment strategy for the isolation and extraction of biomass.
基金supported by the Fundamental Research Funds for the Central Universities(BLX201823)the National Natural Science Foundation of China(21808124)China Postdoctoral Science Foundation(2019M650515 and 2019T120098)。
文摘Lithium(Li)metal is regarded as a promising anode material to render the Li batteries with high energy density and therefore satisfy the ever-growing energy demands of high-end storage devices[1].Unfortunately,the dendrite growth accompanied with accumulation of"dead Li"leads to low Coulombic efficiency,poor cycling lifespan,and even severe safety hazards,critically hindering the practical implementation of Li metal batteries[2,3].
基金financial support from the Fundamental Research Funds for the Central Universities(No.JC2013-3,BLYJ201616)Beijing Higher Education Young Elite Teacher Project(No.YETP0763)
文摘The purpose of this study was to explore the differences of the hemicelluloses extracted by hydrothermal pretreatment using water and alkaline solutions(Na OH or KOH). The physicochemical properties and structural characteristics of two water-soluble and four alkali-soluble hemicelluloses extracted from the triploid of Populus tomentosa Carr. through the hydrothermal pretreatment were comparatively studied. It was observed that the alkalis(Na OH and KOH) were more effective than distilled water as extractants. Sugar analysis showed that xylose(66.83%~86.49%) was the major constituent, followed by glucose(6.83%~18.49%). Mannose(1.40%~8.42%), galactose(2.17%~4.05%), and arabinose(0.21%~2.26%) were also detected in the hemicellulosic fractions. The results of gelpermeation chromatography(GPC) indicated that the hemicelluloses extracted using the alkaline solutions had relatively higher molecular weights than those solubilized in distilled water. Further, based on spectroscopic ~1Hnuclear magnetic resonance(~1H-NMR) and two-dimensional heteronuclear singular quantum correlation(2D-HSQC) analyses, it was confirmed that the hemicellulosic fractions had a major structure of(1→4)-b-D-xylan and a minor structure of(1→4)-a-D-glucan with small amounts of substituted sugars and glucuronic acid attached.
文摘The aromatic nature of lignin makes it a potential renewable source of chemicals and other valuable products.Isolation of lignin from lignocellulosic biomass using organic solvents enables the production of high-purity lignin.The use of formic acid in the organosolv pulping and fractionation process has been widely studied.Characterization of lignin is necessary to achieve valueadded applications of lignin.To simplify the isolation of formic acid-treated lignin,herein,milled wheat straw lignin(MWSL) was employed as an archetype for characterization of the structural changes of lignin during formic acid treatment.The results showed that the MWSL was GSH-type(comprising p-hydroxyphenyl(H),guaiacyl(G),and syringyl(S) monolignols) and underwent structural changes during formic acid treatment.Lignin was esterified during the formic acid treatment.The content of alkyl hydroxyl groups in lignin decreased upon formic acid treatment,corresponding to an increase of the number of double bond equivalents(DBE).Lignin units with active reaction sites were liable to slight condensation,which resulted in a moderate increase of the molecular weight.The molecular weight distribution of formic acid-treated MWSL(FMWSL) was wider than that of the MWSL,although the molecular weight of both species did not differ significantly.The β-O-4 linkage in lignin was partially cleaved during formic acid treatment,resulting in the production of new phenolic structures.This improved the solubility of lignin in the cooking liquor and its reactivity for downstream applications.
基金supported by the Fundamental Research Funds for the Central Universities(BLX201823)Beijing Forestry University Outstanding Young Talent Cultivation Project(2019JQ03017)Beijing Municipal Natural Science Foundation(6182031).
文摘In this article, a facile two-step activation method, coupled with phosphoric acid(H3PO4)-assisted pretreatment and followed KOH activation,was reported for constructing hierarchical porous carbon(HPC) materials derived from lignin. The introduction of H3PO4, cross-linked with lignin sources generated phosphate(and/or polyphosphate) ester groups throughout the lignin structure, which endowed the pre-activated intermediate char(IC)with a hierarchical porous structure. Such phosphate esters contributed to the multi-scale pore structure within the pre-activated IC, which was beneficial for the uniform distribution and impregnation of subsequent KOH activators,thus leading to the formation of HPC materials. The as-prepared HPC exhibited a large specific surface area(SSA) of 1345.1 m^2/g, which ensures the accessibility of the ion diffusion pathways. The supercapacitors integrated with HPC delivered a high specific capacitance of 241 F/g(in a threeelectrode system) and outstanding rate capability with an 80.9% capacitance retention from 0.5 A/g to an ultra-high current density of 50 A/g.
基金The authors are grateful for the financial support by the
文摘Peroxidase plays an important role in living systems;however,its storage difficulty and easy inactivation have limited its applications in complex environments.To address these problems,herein,we proposed a method to synthesize peroxidase mimics by amination,carbonization,and Fe^(3+)-doping of industrial alkali lignin.The Fe^(3+)-doped lignin-based peroxidase mimic(Fe-LPM),with active centers of coordination between Fe^(3+)and N atoms,showed higher tolerance to pH value and temperature than natural peroxidase.Using Fe-LPM,10-100 mmol/L of H_(2)O_(2) and glucose could be colorimetrically detected with the lowest detection limits of 80μmol/L and 1.5 mmol/L and visual detection limits of 1.0 mmol/L and 10 mmol/L,respectively.The Fe-LPM maintained peroxidase-like activity after 10 cycles and could even be used for H_(2)O_(2) detection in practical samples.This work not only provides a new approach to synthesize peroxidase mimics using biomass materials but also promotes the high-value utilization of lignin.
文摘In this study,xylan-based double-network(DN)hydrogels(xylanbased DN gels)with excellent mechanical properties were prepared using acrylic acid and acrylamide(AM)based on a DN approach.The first layer network was obtained by grafting and crosslinking polyacrylic acid(PAA)molecular chains onto xylan with ammonium persulfate(APS)as the initiator and N,N'-methylenebisacrylamide(MBA)as the crosslinking agent;this network was subsequently immersed into an aqueous AM monomer in the presence of APS and MBA for the preparation of the second layer network.The results showed that the double networks were crosslinked by covalent bonds and that the mechanical properties of the xylan-based DN gels were enhanced.Thus,the xylan-based DN gels exhibited a maximum compression stress of 24.9 MPa.The xylan-based DN gels could also recover 97%of their original height after 15 repeated compression cycles;this indicates that the xylan-based DN gels possessed high resistance to friction and wear.Therefore,the prepared xylan-based DN gels have considerable potential for tissue engineering applications.
基金financially supported by the Fundamental Research Funds for the Central Universities (2017TP13)the National Key R&D Program of China (2016YFD0600803)+2 种基金2018 National Student Research Training Program (201710022033)the Innovation Program of College of Materials Science and Technologysupported by the 2017 the international Clean Energy Talent program (No.201702660054)
文摘The conversion of lignocellulose to value-added products is normally focused on fuel production;however,large-scale biorefineries require a cost-effective pretreatment process that can effectively fractionate the three main constituents of lignocellulose for the production of chemicals,fuels,and materials.In this study,a hemicellulosic biopolymer from poplar was fractionated by a mild organosolv process and the effects of various chemicals(sodium hydroxide,triethylamine,and formic acid)and alcohols on the fractionation efficiency and structural variation of hemicellulose were examined.Comparative studies indicated that an acidic catalyst decreased the purity of hemicelluloses by partial degradation of cellulose,and the core of the hemicellulosic biomacromolecule could be released and dissolved under alkaline conditions with 5.8%~19.0%yields.In addition,the use of alcohol with longer alkyl chains facilitated the release of the hemicellulosic biomacromolecule by partially cleaving the ether bonds in the lignincarbohydrate complex(LCC);this is probably due to steric hindrance.The thermal degradation behavior showed that complete pyrolysis was easily achieved for the hemicellulosic polymer with minimal branches irrespective of its molecular weight.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China,China(Nos.21978248,21676223)the Natural Science Foundation of Fujian Province of China(No.2019J06005)+1 种基金Guangdong Provincial Key Research and Development Program(No.2020B0101070001)Open access funding provided by Shanghai Jiao Tong University
文摘Wood-based hydrogel with a unique anisotropic structure is an attractive soft material,but the presence of rigid crystalline cellulose in natural wood makes the hydrogel less flexible.In this study,an all-wood hydrogel was constructed by cross-linking cellulose fibers,polyvinyl alcohol(PVA)chains,and lignin molecules through the Hofmeister effect.The all-wood hydrogel shows a high tensile strength of 36.5 MPa and a strain up to~438%in the longitudinal direction,which is much higher than its tensile strength(~2.6 MPa)and strain(~198%)in the radial direction,respectively.The high mechanical strength of all-wood hydrogels is mainly attributed to the strong hydrogen bonding,physical entanglement,and van der Waals forces between lignin molecules,cellulose nanofibers,and PVA chains.Thanks to its excellent flexibility,good conductivity,and sensitivity,the all-wood hydrogel can accurately distinguish diverse macroscale or subtle human movements,including finger flexion,pulse,and swallowing behavior.In particular,when“An Qi”was called four times within 15 s,two variations of the pronunciation could be identified.With recyclable,biodegradable,and adjustable mechanical properties,the all-wood hydrogel is a multifunctional soft material with promising applications,such as human motion monitoring,tissue engineering,and robotics materials.
基金supported by Beijing Forestry University Outstanding Young Talent Cultivation Project(2019JQ03005)the Young Tip-top Talent Project of Science and Technology Innovation by State Forestry and Grassland Administration of China(2019132609)。
文摘With the world’s fossil fuels being finite in nature,an increasing interest focuses on the application of alternative renewable resources such as biomass.Biomass-derived platform chemicals with abundant functional groups have the potential to replace bulk chemicals for the production of value-added chemicals,fuels,and materials.The upgrading of these platform chemicals relies on the development of efficient catalytic systems.Hydrotalcite,with its wide compositional variety,tuneable anion-exchange capacity,and controlled acidity/basicity sites demonstrates great potential in the catalytic upgrading of biomass and the derived platform chemicals.The past decade has witnessed the emergence of research achievements on the development of efficient and robust hydrotalcite-derived metal catalysts and their applications in the upgrading of biomass or the derived platform chemicals.In this review,we aim to summarize the recent advances on the catalytic upgrading of biomass-derived platform chemicals(e.g.,furfural,5-hydroxymethylfurfural,levulinic acid,and glycerol)via hydrotalcitederived metal catalysts.We also observed that the crucial role of using hydrotalcite-derived catalysts relies on their strong metal–support interactions.As a result,a section focusing on the discussion of the metal–support interactions of hydrotalcitederived catalysts was provided.
基金financially supported by the College Student Research and Career-creation Program of Beijing (S202010022195)
文摘The rheological characteristics of a physical gelation system,in which cellulose nanocrystals(CNC_(s))induced the entanglement of poly(acrylic acid)(PAA)chains and partial hydrophobic association of octylphenol polyoxyethylene acrylate(OP-10-AC)branches in a micellar solution of sodium dodecyl sulfate(SDS),were investigated.The gelation time of the physical gels decreased as the CNC content and number of hydrophobic branch units increased.At the gel point,the storage modulus(G')and loss modulus(G")followed the same frequency dependence(G'≈G"≈ωn),where the hydrophobic moieties attached to the side chains had a significant impact on the values of viscoelastic exponent(n).Beyond the gel point,the initial polymer solution was transformed to a solid-like gel,and the strength of the gel network was governed by associations between both the CNCs and hydrophobic groups.The evolution of the viscoelasticity during the gel-sol transition was monitored,demonstrating that due to a reversible arrangement of the hydrophobic units,a large proportion of physical cross-links dissociated under a thermal trigger and were reversibly reformed when the solution was cooled,while no such partial recovery was observed in the case of the single CNC-induced network systems(with no hydrophobic branches).
基金supported by the State Key Laboratory of Pulp and Paper Engineering (201750)Chinese Ministry of Education (113014A)National Natural Science Foundation of China (21404011, 21674013)
文摘Two-dimensional(2 D) graphene oxide(GO) nanosheets and 1 D2,2,6,6-tetramethylpiperidin-1-oxyl(TEMPO)-oxidized cellulose nanofibers(TOCN) were assembled into GO/TOCN aerogels via a low temperature hydrothermal and freeze-drying process. The as-prepared GO/TOCN aerogels exhibited interconnected 3 D network microstructures, a low density of 6.8 mg/cm^3, a high porosity up to 99.2% and excellent mechanical flexibility.The high porosity in conjunction with their hydrophobicity(contact angle of 121.5°), allowed the aerogels to absorb different organic liquids with absorption capacities up to 240 times of their own weight, depending on the density of the liquids. These results indicated that the aerogels were excellent candidates as sorbent materials for the clean-up of organic liquids. After five absorption-desorption cycles, the absorption capacity of the TOCN carbon aerogels could be regenerated up to 97% of the initial absorption capability,which demonstrated their excellent recyclability.
