Customization of FeNi alloy nanosheet arrays inserted with biomass-derived carbon templates for boosted electromagnetic wave absorption

Electromagnetic wave(EMW)-absorbing materials have considerable capacity in the military field and the prevention of EMW radiation from harming human health.However,obtaining lightweight,high-performance,and broadband EMW-absorbing material remains an overwhelming challenge.Creating dielectric/magnetic composites with customized structures is a strategy with great promise for the development of high-performance EMW-absorbing materials.Using layered double hydroxides as the precursors of bimetallic alloys and combining them with porous biomass-derived carbon materials is a potential way for constructing multi-interface heterostructures as efficient EMW-absorbing materials because they have synergistic losses,low costs,abundant resources,and light weights.Here,FeNi alloy nanosheet array/Lycopodium spore-derived carbon(FeNi/LSC)was prepared through a simple hydrothermal and carbonization method.FeNi/LSC presents ideal EMW-absorbing performance by benefiting from the FeNi alloy nanosheet array,sponge-like structure,capability for impedance matching,and improved dielectric/magnetic losses.As expected,FeNi/LSC exhibited the minimum reflection loss of-58.3 dB at 1.5 mm with 20wt%filler content and a widely effective absorption bandwidth of 4.92 GHz.FeNi/LSC composites with effective EMW-absorbing performance provide new insights into the customization of biomass-derived composites as high-performance and lightweight broadband EMW-absorbing materials.

Review of Carbon Dots from Lignin: Preparing, Tuning, and Applying

Carbon dots(CDs),emerging carbon materials with unique physical and chemical properties,have drawn extensive attention from researchers.In recent years,many carbon sources have been used as precursors for preparing CDs.In contrast to other types of precursors,lignin,as a renewable and available source of natural aromatic biopolymers,is believed to be a low-cost precursor for the large-scale preparation of CDs.However,the preparation of CDs with excellent optical properties from lignin has some drawbacks because of the complex structure of lignin.Hence,the methods for preparing the CDs from lignin are summarized in this paper,and the mechanism and physical and chemical properties of lignin-based CDs are discussed.Moreover,some approaches to tuning the optical properties of lignin-based CDs have been proposed.Additionally,the use of lignin-based CDs in the fields of sensing,supercapacitor,bioimaging,anti-counterfeiting,and information encryption is reviewed.

Oxygen-doped Carbon Nitride Nanocages with Efficient Photon-to-Electron Conversion for Selective Oxidation of Xylose/Xylan to Yield Xylonic Acid

Highly efficient photon-to-electron conversion is crucial for achieving photocatalytic conversion.In this study,oxygen-doped carbon nitride nanocages(O@CNNCs)were engineered via dual strategies of morphology-controlled heteroatom doping,which was successfully used in the photocatalytic selective oxidation of xylose/xylan to xylonic acid.The nanocage-shaped O@CNNCs had a larger surface area,which was 4.02 times of carbon nitride(CN).Furthermore,with the assistance of morphology regulation and O-doping,O@CNNCs exhibit highly efficient photon-to-electron conversion,enhanced visible-light utilization,high photocurrent,low resistance,and fast separation/migration of electron-hole pairs.Correspondingly,the photocatalytic oxidation of xylose to xylonic acid using O@CNNCs was successfully achieved under mild reaction conditions with a yield of 83.4%.O@CNNCs have excellent recyclability,in which the yield of xylonic acid in the 5th cycle was 98.2%of its initial use.The O@CNNC photocatalytic system was also suitable for macromolecular xylan,and a xylonic acid yield of 77.34 mg was obtained when 100 mg xylan was used.The oxidation-active species captured experiments indicated that holes were crucial for the selective oxidation of xylose to xylonic acid.Overall,this study provides a new strategy for the preparation of photocatalysts with excellent photon-to-electron conversion and selective oxidation of biomass-derived feedstocks to xylonic acid.

Advances Toward Sustainable Lignin-based Gel for Energy Storage and Smart Sensing

Polymers obtained from biomass are promising alternatives to petrobased polymers owing to their low cost,biocompatibility,and biodegradability.Lignin,a complex aromatic polymer containing several functional hydrophilic and active groups including hydroxyls,carbonyls,and methoxyls,is the second most abundant biopolymer in plants.In particular,sustainable ligninbased gels are emerging as an appealing material platform for developing energy-and sensing-related applications owing to their attractive and tailorable physiochemical properties.This study describes the preparation strategies of lignin-based gels according to previously reported methods,with significant attention on the diverse performance of lignin-derived gel materials.Additionally,a detailed review of lignin-based gels utilized as an important resource in diverse fields is provided.Finally,a future vision on challenges and their possible solutions is presented.

Building the conformal protection of VB-group VS_(2)laminated heterostructure based on biomass-derived carbon for excellent broadband electromagnetic waves absorption

Although VB-Group transition metal disulfides(TMDs)VS_(2)nanomaterials with specific electronic properties and multiphase microstructures have shown fascinating potential in the field of electro-magnetic wave(EMW)absorption,the efficient utilization of VS_(2)is limited by the technical bottleneck of its narrow effective absorption bandwidth(EAB)which is attributed to environmental instability and a deficient electromagnetic(EM)loss mechanism.In order to fully exploit the maximal utilization values of VS_(2)nanomaterials for EMW absorption through mitigating the chemical instability and optimizing the EM parameters,biomass-based glucose derived carbon(GDC)like sugar-coating has been decorated on the surface of stacked VS_(2)nanosheets via a facile hydrothermal method,followed by high-temperature carbonization.As a result,the modulation of doping amount of glucose injection solution(Glucose)could effectively manipulate the encapsulation degree of GDC coating on VS_(2)nanosheets,further imple-menting the EM response mechanisms of the VS_(2)/GDC hybrids(coupling effect of conductive loss,interfacial polarization,relaxation,dipole polarization,defect engineering and multiple reflections and absorptions)through regulating the conductivity and constructing multi-interface heterostructures,as reflected by the enhanced EMW absorption performance to a great extent.The minimum reflection loss(Rmin)of VS_(2)/GDC hybrids could reach52.8 dB with a thickness of 2.7 mm at 12.2 GHz.Surprisingly,compared with pristine VS_(2),the EAB of the VS_(2)/GDC hybrids increased from 2.0 to 5.7 GHz,while their environmental stability was effectively enhanced by virtue of GDC doping.Obviously,this work provides a promising candidate to realize frequency band tunability of EMW absorbers with exceptional perfor-mance and environmental stability.

Clean production of lactic acid by selective carbon-carbon bond cleavage of biomass feedstock over a novel carbon-bismuth oxychloride photocatalyst

The use of functional materials such as carbon-bismuth oxyhalides in integrated photorefineries for the clean production of fine chemicals requires restructuring.A facile biomass-assisted solvothermal fabrication of carbon/bismuth oxychloride nanocomposites(C/BiOCl)was achieved at various temperatures.Compared with BiOCl and C/BiOCl-120,C/BiOCl-180 exhibited higher crystallinity,wider visible light absorption,and a faster migration/separation rate of photoinduced carriers.For the selective C–C bond cleavage of biomass-based feedstocks photocatalyzed by C/BiOCl-180,the xylose conversion and lactic acid yield were 100%and 92.5%,respectively.C/BiOCl-180 efficiently converted different biomass-based monosaccharides to lactic acid,and the efficiency of pentoses was higher than that of hexoses.Moreover,lactic acid synthesis was favored by all active radicals including superoxide ion(·O_(2)^(−)),holes(h^(+)),hydroxyl radical(·OH),and singlet oxygen(^(1)O_(2)),with·O_(2)^(−)playing a key role.The fabricated photocatalyst was stable,economical,and recyclable.The use of biomass-derived monosaccharides for the clean production of lactic acid via the C/BiOCl-180 photocatalyst has opened new research horizons for the investigation and application of C–C bond cleavage in biomass-based feedstocks.

Cuprous oxide/copper oxide interpenetrated into ordered mesoporous cellulose-based carbon aerogels for efficient photocatalytic degradation of methylene blue

The casual discharge of dyes from industrial settings has seriously polluted global water systems.Owing to the abundance of biomass resources,preparing photocatalysts for photocatalytic degradation of dyes is significant;however,it still remains challenging.In this work,a cuprous oxide/copper oxide composite was interpenetrated onto carbon nanosheets of cellulose-based flexible carbon aerogels(Cu_(2)O/CuO@CAx)via a simple freeze-drying-calcination method.The introduction of the carbon aerogel effectively prevents the aggregation of the cuprous oxide/copper oxide composite.In addition,Cu_(2)O/CuO@CA0.2 has a larger specific surface area,stronger charge transfer capacity,and lower recombination rate of photogenerated carriers than copper oxide.Moreover,Cu_(2)O/CuO@CA0.2 exhibited high photocatalytic activity in decomposing methylene blue,with a degradation rate reaching up to 99.09% in 60 min.The active oxidation species in the photocatalytic degradation process were systematically investigated by electron spin resonance characterization and poisoning experiments,among which singlet oxygen played a major role.In conclusion,this work provides an effective method for preparing photocatalysts using biomass resources in combination with different metal oxides.It also promotes the development of photocatalytic degradation of dyes.

Nanosilver anchored alginate/poly(acrylic acid/acrylamide) double-network hydrogel composites for efficient catalytic degradation of organic dyes

A novel alginate/poly(acrylic acid/acrylamide)double-network hydrogel composite with silver nanoparticles was successfully fabricated using the sol–gel method.The presence of carboxyl and amide groups in the network structure provided abundant active sites for complexing silver ions,facilitating the in situ reduction and confinement of silver nanoparticles.In batch experiments,the optimal silver loading was 20%,and 5 mmol·L^(–1) of p-nitrophenol was completely degraded in 113 s with a rate constant value of 4.057×10^(−2) s^(–1).In the tap water system and simulated seawater system,the degradation time of p-nitrophenol at the same concentration was 261 and 276 s,respectively,with a conversion rate above 99%.In the fixed-bed experiment,the conversion rate remained above 74%after 3 h at a flowing rate of 7 mL·min^(–1).After 8 cycling tests,the conversion rate remained at 98.7%.Moreover,the catalyst exhibited outstanding performance in the degradation experiment of four typical organic dyes.

Catalytic degradation of organic pollutants for water remediation over Ag nanoparticles immobilized on amine-functionalized metalorganic frameworks

Developing efficient catalysts for organic pollutants degradation is crucial for remediating the current severe water environment,yet remains a great challenge.Herein,we report silver nanoparticles immobilized on an amine-functionalized metal-organic framework(MOFs)(Ag/UiO-66-NH_(2))as a robust catalyst for the reduction of 4-nitrophenol(4-NP).The fabricated Ag/UiO-66-NH_(2)catalyst exhibits the merits of superior activities(high turnover frequency(TOF)3.2×10^(4)h^(-1)and k value 6.9×10^(-2)s^(-1)),costeffectiveness under the lowest NaBH4 concentration(n[NaBH_(4)]/n[4-NP],200),outstanding cyclability(10 recycling runs),and observable long-term durability,significantly outperforming previously reported catalytic system.The excellent degradation efficiency is ascribed to the favorable microenvironment modulation of unique MOF structure,which regulates the intrinsic properties of active sites and improves the electron-transfer process.Notably,the Ag/UiO-66-NH_(2)also promotes the catalytic degradation of several organic pollutants at room temperature and hence could find a broad application for water remediation.This work offers a new avenue for the development of high-performance MOF-based catalysts with excellent activity and durability.