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Derived from lignocellulosic biomass, sustainable hard carbon has emerged as a promising low-cost anode material for sodium-ion batteries (SIBs). However, the intricate formation process of the hard carbon microstructure remains unclear. This study investigates the structural differences and pyrolysis behaviors of pine lignin and its graded variants obtained through a lignin molecular sieving engineering strategy. Moreover, it delves into the relationship between the microstructure of lignin-derived hard carbon and its sodium-ion storage characteristics. Pristine pine lignin, along with ethanol-isolated lignin, acetone-isolated lignin, and residual lignin, serves as a precursor for synthesizing hard carbon materials. Quantitative analysis via31P NMR spectroscopy reveals the highest content of polar functional groups in ethanol-isolated lignin. Interestingly, hard carbon derived from ethanol-isolated lignin exhibits the smallest closed pore volume, leading to the lowest plateau capacity of sodium-ion storage. Conversely, hard carbon derived from acetone-dissolved lignin displays the highest plateau capacity owing to its largest closed pore volume formed in the carbonization process. The origin of open and closed pore structures of hard carbons is thoroughly analyzed. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) are widely used in portable energy storage. The capacity of commercial graphite is difficult to improve due to the stoichiometry limit of LiC6 of graphite, thus new anodes need to be developed to meet the demand of high-energy–density LIB. The growing interest in graphitized carbon nitride (g-C3N4) stems from its structural resemblance to graphite and its capacity to offer abundant adsorption and intercalation sites. However, g-C3N4, as a semiconductor, has a low lithium transfer rate due to its poor conductivity and high diffusion resistance. Improving the electron transport rate of g-C3N4 and reducing the adsorption energy barrier of Li+ in g-C3N4 are the keys to improving the electrochemical performances of g-C3N4. In this study, lignin and melamine were homogeneously mixed using the spray drying method, followed by the preparation of covalently bonded C3N4/LC material through a one-step carbonization process. The uniform dispersion of g-C3N4 in amorphous carbon can improve the conductivity and reduce the diffusion energy barrier of Li+. As a result, the C3N4/LC-x anode has better electrochemical behavior, including higher reversible capacity, better rate performance, and cycle stability. Highlights: • The covalently bonded C3N4/LC-x material was prepared through a one-step carbonization method. • The uniform dispersion of g-C3N4 in amorphous carbon could improve the electronic conductivity and reduce the diffusion energy barrier of Li+ ions. • C3N4/LC-2 showed high reversible capacity, ideal rate performance, and cycle life. [ABSTRACT FROM AUTHOR]

Lignocellulose flow fuel cells are promising technologies for large scale generation of renewable electricity at low temperature. However, most of them have low electron transfer kinetics and require pre-reaction and redox mediators in anolytes for a liquid-phase catalytic reaction, which leads to low power density, energy consumption and resource waste. Herein, we develop a new low temperature and high-power density lignin flow fuel cell (LFFC) catalyzed by CoMn-LDH electrocatalysts with superhydrophilic intercalation on the anode to efficiently degrade lignin and transfer electrons rapidly. The experiments and DFT calculations show that CoMn-LDH exhibits high adsorption capacity for lignin due to its superhydrophilic intercalation, and has good electrical conductivity due to the greater overlap of antibonding orbitals and high continuity at the Fermi level. Moreover, the abundant oxygen defects of CoMn-LDH can depolymerize lignin effectively. Thus, the prepared CoMn-LDH electrocatalyst enables fast charge transfer and high catalytic efficiency. The power density of the designed LFFC reached 269.3 mW cm−2, and the generated electrical energy is 294.7 mW h based on 1.0 g of lignin, which are obviously higher than those of the reported LFFCs. Furthermore, it can work stably for more than 9 h at 0.3 V and 413.5 mA cm−2, and successfully power a 1.5 V LED pattern with only a 1 cm2 active membrane. It presents a promising approach for developing high-power density LFFCs towards a sustainable society. [ABSTRACT FROM AUTHOR]

This study employs a combined computational and experimental approach to elucidate the mechanisms governing the interaction between lignin and urea, impacting lignin dissolution and subsequent aggregation behavior. Molecular dynamics (MD) simulations reveal how the urea concentration and temperature influence lignin conformation and interactions. Higher urea concentrations and temperatures promote lignin dispersion by disrupting intramolecular interactions and enhancing solvation. Density functional theory (DFT) calculations quantitatively assess the interaction energy between lignin and urea, supporting the findings from MD simulations. Anti-solvent precipitation demonstrates that increasing the urea concentration hinders the self-assembly of lignin nanoclusters. The findings provide valuable insights for optimizing lignin biorefinery processes by tailoring the urea concentration and temperature for efficient extraction and dispersion. Understanding the influence of urea on lignin behavior opens up avenues for designing novel lignin-based materials with tailored properties. This study highlights the potential for the synergetic application of MD simulations and DFT calculations to unravel complex material interactions at the atomic level. [ABSTRACT FROM AUTHOR]

In this perspective, we present an overview of the research and advancement of lignocellulose-derived hard carbon anodes and their pivotal role in the commercialization of sodium-ion batteries. Hard carbon anodes, sourced from lignocellulosic biomasses, exhibit considerable promise due to their widespread availability, economical viability, and environmentally friendly attributes with zero carbon-dioxide emissions. Given the intricate compositions and composite nature of lignocellulosic materials, it becomes imperative to prioritize factors crucial for the fabrication of hard carbon anodes that exhibit enhanced sodium-ion storage capabilities. Thus, our study offers an extensive overview of the structure and performance nuances of hard carbon anodes derived from cellulose, hemicellulose, and lignin. Furthermore, it delves into the fundamental principles governing synthesis methodologies and confronts the challenges inherent in producing lignocellulose-derived hard carbon anodes tailored specifically for sodium-ion batteries. Highlights: • Lignocellulose is a promising low-cost precursor for the hard carbon anodes in sodium-ion batteries. • Chemical, crystalline, components, and multi-dimensional structures of lignocellulose influence the structure and performance of hard carbon anodes. • Engineering methodologies tuning the microstructures of lignocellulose could change the intrinsic structure and performances of hard carbon anodes. • New methods also need to consider the principles of green chemistry and sustainable development. [ABSTRACT FROM AUTHOR]

The development of inexpensive and robust bifunctional electrocatalysts for hydrogen evolution reactions (HER) and oxygen evolution reactions (OER) was crucial for renewable energy systems. Herein, a novel strategy for preparing CoNiRu alloy nano‐electrocatalyst capsulated by nitrogen‐doped biochar (CoNiRu@NLC) using carboxymethylated lignin macromolecules was proposed. CoNiRu@NLC exhibited excellent HER and OER performance, and the overall water splitting voltage was only 1.47 V at 10 mA/cm2 with excellent catalytic stability, which was superior to the noble metal catalysts Pt/C ‖ RuO2. Theoretical calculations confirmed the strong electron interaction between CoNiRu alloy and carbon layer, and XPS patterns proved that the electrons transfer from Ru to CoNi, significantly boosted the electrocatalytic activity. This study demonstrated the importance of lignin‐driven alloying on enhancing catalytic performance and provided a concept for the development of high‐efficiency catalysts and high‐value utilization of polyphenol biomass. [ABSTRACT FROM AUTHOR]

The biomass flow fuel cell (BFFC) is a promising technology for realizing a sustainable society. However, BFFCs generally require electron mediators and complex pretreatment, resulting in miscellaneous ion pollution and energy consumption. Herein, we develop a lignin flow fuel cell (LFFC) for self-generating electricity via the privileged structure and redox chemistry of lignin without any electron mediators and pre-reaction. The experiments and theoretical simulations reveal that lignin can automatically release electrons by its oxidation and cleavage under a high voltage difference to achieve high cell performance. Interestingly, phenolic lignin model compounds with more methoxy groups exhibit higher cell performance because the methoxy groups can significantly reduce their HOMO–LUMO energy gaps and oxidation potentials, which is beneficial for releasing electrons. When industrial lignin was utilized as the fuel, the LFFC achieved a high power density of 159.9 mW cm−2 and worked stably for more than 8 h with 5.0 g lignin. Moreover, the LFFC fueled by 1.0 g lignin can output 219.9 mW h electrical energy, which is significantly higher than that of the reported BFFCs. Furthermore, the scale-up of the LFFC can power several electrical devices simultaneously at room temperature. This work provides a promising approach for next-generation LFFCs with low cost and high performance towards a sustainable future. [ABSTRACT FROM AUTHOR]

As a new type of green photothermal material, lignin exhibits an excellent photothermal effect due to its abundant aromatic rings and π–π conjugated structure. To develop value-added applications of lignin in the photothermal field, it is important to explore strategies for regulating the photothermal conversion of lignin. In this work, the photothermal effect of lignin was improved significantly through modification with an electron-withdrawing group. The introduction of acetyl resulted in the formation of an electron donor–acceptor (D–A) structure in lignin and enhanced the light absorption ability. The intermolecular interaction among lignin molecules also decreased after modification with acetyl groups, leading to enhanced non-radiative decay induced by molecular motion. Under 808 nm laser irradiation at 0.51 W cm−2, the photothermal conversion efficiency of acetylated lignin (ACAL) reached as high as 73.2%, which was 37% higher than that of unmodified lignin. This study provides a new strategy to enhance the photothermal effect of lignin and deepens the understanding of the lignin photothermal mechanism. [ABSTRACT FROM AUTHOR]

Condensation, dark color and low extraction yield of lignin have hindered the full valorization of biomass during lignocellulosic fractionation. Herein, we introduce a novel biomass fractionation concept that addresses the issue of lignin's spatial confinement. Building upon this concept, we have devised an environmentally friendly and straightforward strategy. This approach involves a combination of selective carboxylation at the Cγ-OH position using citric acid and etherification at the Cα-OH position using butanol. The objective is to mitigate the spatial confinement of lignin and stabilize its active intermediates for lignin extraction. Consequently, up to 91.4 ± 0.2% lignin with a light color can be separated from the recalcitrant softwoods, as a UV blocker to improve the performance of sunscreen cream. The cellulosic residue can be enzymatically digested to glucose with a yield of 80%. The initiated biomass fractionation theory and strategy in this study provide a new concept for the isolation of lignin and full valorization of lignocellulose, promoting the development of a sustainable economy. [ABSTRACT FROM AUTHOR]

The conventional fractionation of lignocellulose into cellulose, hemicellulose, and lignin was generally carried out at high temperatures and under highly acidic conditions owing to the rigid matrix of lignocellulose and crystallinity of cellulose, causing the degradation of carbohydrates and condensation of lignin, thus hindering their value-added utilization. In this study, a stepwise fractionation method was proposed in which microwave-assisted fractionation of hemicellulose under mild conditions contributed to 81.9% of xylose yield; then, the cellulose part solid was rapidly dissolved in LiBr molten salt hydrate (LiBr-MSH) solution, followed by a filtration process to isolate lignin solid. It was found that the removal of hemicellulose provided more pores for the next dissolution of cellulose, and LiBr-MSH caused the cleavage of the hydrogen bonds of cellulose. Consequently, the cellulose part solid was rapidly dissolved in LiBr-MSH. The results showed that under the optimal fractionation conditions, 78.0% yield of glucan oligomers and 89.7% purity of noncondensed lignin were obtained from cellulose fractionation and filtration, respectively. A high β-O-4 bond content close to 87.3% of the theoretical maximum yield was detected in the obtained lignin, indicating that most β-O-4 bond structure of lignin was well preserved. Additionally, the isolated lignin can be selectively depolymerized into aromatic monomers with a high yield of 20.4%, which is 74.2% of the theoretical maximum yield. [ABSTRACT FROM AUTHOR]

Lignin exhibits a long‐active UV‐blocking property due to its macromolecular aromatic structure and unique semiquione‐quione‐hydroquione transition. However, its poor absorbance in UVA region (320–400 nm) and irregular aggregation are still the obstacles. Herein, active spirapyrane (SP‐Br) is synthesized and covalently introduced into alkali lignin (AL) to construct photo‐stimulated UV‐absorbing enhancement sunscreen actives (AL‐SPn). The introduction of SP significantly improved the absorbance of AL in UVA region and its aggregation is effectively eased. When the optimal AL‐SP3 solution is exposed to UV irradiation, the color turned purple, and the absorbance in UVA region further improved as the unconjugated SP transformed into conjugated merocyanine (MC) structure. When the light is removed, the solution recovered light yellow. The antioxidant property of AL endow the reversible SP‐MC transformation with good cyclic stability. As‐prepared AL‐SP3 based sunscreen exhibit obvious photo‐stimulated enhancement effect. The sun protection factor (SPF) improved from 23 to 89 after 4 h irradiation, and can maintain the high performance for another 8 h. In addition, it exhibit low permeation and good biocompatibily in vitro and vivo, demonstrating its good potential in practical use. [ABSTRACT FROM AUTHOR]

Lignin, rich in β‐O‐4 bonds and aromatic structure, is a renewable and potential resource for value‐added chemicals and promoting H2 evolution. However, direct photo‐reforming lignin remains a huge challenge due to its recalcitrant structure. Herein, a collaborative strategy is proposed by dispersing Pt on zinc‐vacancy‐riched ZnIn2S4 (Pt/VZn‐ZIS) for revealing the effect of lignin structure during photo‐reforming process with lignin models. And a series of theoretical calculations and experimental results show that lignin model substances with more nucleophilic group structures will have a stronger tendency to occur the photo‐reforming reactions. In addition, benefiting of Pt‐S electronic channel is formed by occupying Pt atom onto zinc vacancies in ZnIn2S4, which can effectively reduce the energy barrier of H2 evolution and accompany the selective oxidation of lignin model from Cα‐OH to Cα = O under simulated sunlight. The natural lignin is used to further demonstrate this selective oxidation mechanism. The presented work demonstrates the photo‐reforming lignin model mechanism and the influence of lignin‐structure during the process of photo‐reforming. [ABSTRACT FROM AUTHOR]

Rational design of efficient, stable, and inexpensive bifunctional electrocatalysts for oxygen evolution reactions (OER) and hydrogen evolution reactions (HER) is a key challenge to realize green hydrogen production via electrolytic water splitting. Herein, Ru nanoparticles and FeNi alloy heterojunction catalyst (Ru−FeNi@NLC) encapsulated via lignin‐derived carbon was prepared by self‐assembly precipitation and in situ pyrolysis. The designed catalyst displays excellent performance at 10 mA cm−2 with low overpotentials of 36 mV for HER and 198 mV for OER, and only needs 1.48 V for overall water splitting. Results and DFT calculations show the unique N‐doped lignin‐derived carbon layer and Ru−FeNi heterojunction contribute to optimized electronic structure for enhancing electron transfer, balanced free energy of reactants and intermediates in the sorption/desorption process, and significantly reduced reaction energy barrier for the HER and OER rate‐determining steps, thus improved reaction kinetics. This work provides a new in situ pyrolysis doping strategy based on renewable biomass for the construction of highly active, stable and cost‐effective catalysts. [ABSTRACT FROM AUTHOR]

Lignin valorization is a challenge for chemical and materials scientists due to its complex molecular structure and intra- and inter-molecular assembly. Although catalytic conversion of lignin into small aromatic organic molecules has been widely investigated, it faces the problems of low selectivity and complex products. Herein, we report a direct electrochemical conversion method for the selective oxidation of industrial lignin to produce short-chain carboxylic acids (SCCAs) with a wide range of concentrations. In an electrolytic cell, lignin is chemically converted to SCCAs by H2O2 with titanium silicate-1 (TS-1) as a catalyst. H2O2 is generated in situ by the recombination of H+ and HO2− in a three-compartment cell by separately introducing hydrogen (H2) and oxygen (O2) as the sources of protons and HO2− into the anode and cathode compartments. We have achieved a record-high concentration of SCCAs up to 109.8 mg mL−1 through the catalytic depolymerization of lignin. A high concentration of SCCAs of 80.1 mg mL−1 could also be achieved at a cell voltage of 2.13 V by coupling the 2e−-ORR and water oxidation using air and 1 M aqueous H2SO4 solution as feedstocks. Our approach could eliminate the additional economic consumption and environmental hazards caused by the transportation and storage of commercially concentrated and stabilized H2O2. Aside from the SCCAs produced in this process, the formation of new carboxyl groups in the lignin residue during the oxidation reaction greatly broadens the application potential of industrial lignin. [ABSTRACT FROM AUTHOR]

Highlights: The N/S co-doped lignin-derived porous carbon (NSLPCs) with ultra-high heteroatom doping was prepared through a novel supramolecule-mediated pyrolysis strategy. Covalently bonded graphitic carbon/amorphous carbon intermediates induce the formation of high heteroatom doping. The high heteroatom doping of NSLPC could provide abundant defective active sites for the adsorption of K+. Amorphous carbons are promising anodes for high-rate potassium-ion batteries. Most low-temperature annealed amorphous carbons display unsatisfactory capacities. Heteroatom-induced defect engineering of amorphous carbons could enhance their reversible capacities. Nevertheless, most lignocellulose biomasses lack heteroatoms, making it a challenge to design highly heteroatom-doped carbons (> 10 at%). Herein, we report a new preparation strategy for amorphous carbon anodes. Nitrogen/sulfur co-doped lignin-derived porous carbons (NSLPC) with ultra-high nitrogen doping levels (21.6 at% of N and 0.8 at% of S) from renewable lignin biomacromolecule precursors were prepared through a supramolecule-mediated pyrolysis strategy. This supermolecule/lignin composite decomposes forming a covalently bonded graphitic carbon/amorphous carbon intermediate product, which induces the formation of high heteroatom doping in the obtained NSLPC. This unique pyrolysis chemistry and high heteroatom doping of NSLPC enable abundant defective active sites for the adsorption of K+ and improved kinetics. The NSLPC anode delivered a high reversible capacity of 419 mAh g‒1 and superior cycling stability (capacity retention of 96.6% at 1 A g‒1 for 1000 cycles). Potassium-ion hybrid capacitors assembled by NSLPC anode exhibited excellent cycling stability (91% capacity retention for 2000 cycles) and a high energy density of 71 Wh kg–1 at a power density of 92 W kg–1. [ABSTRACT FROM AUTHOR]

Poly(butylene adipate‐co‐terephthalate) (PBAT) is a type of synthetic biodegradable thermoplastic copolyester with comparable mechanical properties to polyethylene, but the application of PBAT is limited by factors such as high cost, short shelf life, poor weather and water resistance. In order to develop PBAT composites with high performance and low cost, lignin‐modified PBAT biocomposites with enhanced tensile strength were prepared via in‐situ construction of interfacial dynamic bonds. Zinc stearate and epoxy soybean oil were introduced as the interfacial modifiers to construct dynamic bonds between lignin and PBAT, so as to improve the interfacial compatibility. The results demonstrated that the lignin/PBAT biocomposite with interface modifiers reached the maximum tensile strength of 36.7 MPa and an elongation at break of 725.3% at the lignin content of 5 wt%, with the tensile strength achieved 5% improvement on the basis of pure PBAT (34.9 MPa and 717.6%). When the lignin content was increased to 10 wt%, the lignin/PBAT biocomposite with interfacial modifiers still maintained the tensile strength of 35.4 MPa and the elongation at break of 627.8%, which was 82% and 31% higher than that of the directly compounded sample without interfacial modifiers, respectively. Even when the content of lignin loading increased to 20 and 30 wt%, the mechanical properties of the composites were still significantly improved by adding modifiers. The hydrophobicity of the composite was also improved after in‐situ interfacial modification. The strategy demonstrated in this work provides an effective reference for the development of lignin/PBAT composites with high performance but low cost. [ABSTRACT FROM AUTHOR]

Remote controllable photothermal elastomers can realize precise non-contact control through the photothermal conversion effect, highlighting a new routine for light energy utilization and a promising direction for smart materials. Developing biomass-based photothermal materials is an important strategy to promote the realization of carbon neutrality and improve the environmental friendliness of photothermal elastomers. In this work, green biomass lignin was demonstrated as an efficient photothermal agent for preparing smart elastomer composites with versatile functionalities, owing to the fact that the conjugated structures in lignin could effectively promote electron transitions from low-energy orbitals to high-energy states and the visible and near-infrared (NIR) light energy absorbed by lignin was mainly released in the form of non-radiative transition. A high photothermal conversion efficiency of 53.7% was obtained for low molecular weight alkaline lignin with the photothermal temperature exceeding 280 °C under NIR irradiation (808 nm, 1.25 W cm−2). Under the stimulation of NIR light, the alkaline lignin/polyethylene elastomer (POE) composite exhibited a good light-triggered shape memory effect, excellent light-controlled self-repairing properties with the self-repairing efficiency as high as 98.2% (808 nm, 1.25 W cm−2, 20 min), and strong photothermal bactericidal activity. Meanwhile, a series of functional applications were demonstrated based on the excellent photothermal effect of lignin, such as photothermal engines, photothermal generators and photothermal switches, which endowed lignin-based elastomer composites with considerable application prospects in smart materials for precise remote driving of robots, machines, sensors, sterilization and self-repairing equipment, etc., promoting the sustainable development and high-value utilization of biomass lignin. [ABSTRACT FROM AUTHOR]

Understanding the molecular mechanism of lignin nanoparticle (LNP) formation will precisely instruct its functionalization, which is of importance for biomass valorization. Trial-and-error approaches for mechanistic research at the molecular level are extremely difficult and resource intensive. Here we have revealed that the intra-molecular interactions of lignin aromatic rings were the internal force driving the aggregation of lignin into LNPs by combining molecular simulation with experimental methods. A quantitative aromatic interaction correlated with the configuration distribution of lignin dimer and LNP yields was also developed for guiding the synthesis and functionalization of LNPs. A cellulose-derived solvent, γ-valerolactone (GVL), was then screened out to sustain lignin molecules' intramolecular stacking (−5.54 kJ mol−1) into a spherical nucleus for the growth of a uniform and stable lignin nanosphere during solvent shifting. With the assistance of the LNP formation mechanism, lignin could successfully stabilize in situ generated gold nanoparticles with excellent photothermal performance during the production of LNPs in a GVL/water solution. The newly proposed mechanism will provide an important theoretical basis for upgrading lignin to value-added biomaterials in a green and facile pathway. [ABSTRACT FROM AUTHOR]

Lignin, one of the renewable constituents in natural plant biomasses, holds great potential as a sustainable source of functional carbon materials. Tremendous research efforts have been made on lignin‐derived carbon electrodes for rechargeable batteries. However, lignin is considered as one of the most promising carbon precursors for the development of high‐performance, low‐cost porous carbon electrode materials for supercapacitor applications. Yet, these efforts have not been reviewed in detail in the current literature. This review, therefore, offers a basis for the utilization of lignin as a pivotal precursor for the synthesis of porous carbons for use in supercapacitor electrode applications. Lignin chemistry, the synthesis process of lignin‐derived porous carbons, and future directions for developing better porous carbon electrode materials from lignin are systematically reviewed. Technological hurdles and approaches that should be prioritized in future research are presented. [ABSTRACT FROM AUTHOR]

Typically, pristine lignin is considered to have limited application in the flame retardance area, and the phosphorylation of lignin or its combination with other effective flame retardants is required to help polyurethane achieve flame retardance. Herein, three types of lignin, including sodium lignosulfonate (LS), alkaline lignin (AL) and enzymatic hydrolysis lignin (EHL), were solely applied to significantly enhance the flame retardance and thermostability of PU foams. The PU foam coated with AL or LS could show evidently enhanced flame retardance by growing dense and swelling char, radical capture and inert gas dilution to protect the PU foam from fire and heat, and the limited oxygen index could reach as high as 28.4%. The thermostability of the coated PU foam was significantly improved by retaining 44% of its weight at 900 °C. The flame retardance mechanism of lignin/PU foam was attributed to the fact that lignin could change the thermal degradation and burning behavior of PU foams in the condensed phase (char forming) and the gas phase (inert gas dilution), and by radical quenching (phenolic groups) and S–N synergism. Our research has proved that lignin alone could help PU foam and cotton fabric achieve complete flame retardance, without any phosphorylated modification or the combination with other flame retardant agents. [ABSTRACT FROM AUTHOR]

The supermolecule-mediated method is employed to prepare an organic molecule aggregate (OMA) precursor called MCAL in which the dopant agent (melamine-cyanuric acid supramolecular (MCA)) and biomass molecule (alkali lignin (AL)) are uniformly mixed. Direct pyrolysis of OMA yields lignin-derived highly nitrogen-doped turbine-like carbon (LNTC), which serves as a high-performance anode for potassium-ion capacitors. [Display omitted] Potassium-ion hybrid capacitors (PIHCs) represent a burgeoning class of electrochemical energy storage devices characterized by their remarkable energy and power densities. Utilizing amorphous carbon derived from sustainable biomass presents an economical and environmentally friendly option for anode material in high-rate potassium-ion storage applications. Nevertheless, the potassium-ion storage capacity of most biomass-derived carbon materials remains modest. Addressing this challenge, nitrogen doping engineering and the design of distinctive nanostructures emerge as effective strategies for enhancing the electrochemical performance of amorphous carbon anodes. Developing highly nitrogen-doped nanocarbon materials is a challenging task because most lignocellulosic biomasses lack nitrogen functional groups. In this work, we propose a general strategy for directly carbonizing supermolecule-mediated lignin organic molecular aggregate (OMA) to prepare highly nitrogen-doped biomass-derived nanocarbon. We obtained lignin-derived, highly nitrogen-doped turbine-like carbon (LNTC). Featuring a three-dimensional turbine-like structure composed of amorphous, thin carbon nanosheets, LNTC demonstrated a capacity of 377 mAh g−1 when used as the anode for PIHCs. This work also provides a new synthesis method for preparing highly nitrogen-doped nanocarbon materials derived from biomass. [ABSTRACT FROM AUTHOR]

Airborne pollutants including particulate matter (PM) and microorganisms threaten public health. Fibrous filters in personal protection equipment have shown good PM removal ability but a poor biocidal effect. Herein, a series of highly biocompatible amino acid-grafted enzymatic hydrolysis lignin derivatives (EHL-AA-x) with both cationic/anionic groups were synthesized by nucleophilic substitution. The structures of EHL-AA-x were characterized by NMR, FT-IR, GPC, DLS, potentiometric titration, surface charge and elemental analysis. In vitro biological assays showed that the inhibition efficiency of EHL-AA-x against Gram-negative bacteria increased from 10 to 57% when the grafting amount of amino acids varied from 0 to 0.62 mmol g−1 at a concentration of 10 mg mL−1, while that against Gram-positive bacteria reached 99%. It is not only 4 times higher than that of birch wood hydrotropic lignin, but also comparable to that of lignin/nanosilver composites. The morphological changes observed by SEM indicated that EHL-AA-x damaged the cell membrane of bacteria, suggesting a membrane disruption mechanism. QCM-D and AFM analysis showed that the increase of electrostatic and hydrophobic interactions between EHL-AA-x and bacteria is the key factor for the improvement of the antimicrobial activity. Subsequently, a mask fabricated from the optimal EHL-AA-x-coated non-woven fabrics could inhibit >95% bacteria in 30 min, while a number of living bacteria were detected on the inner layer of the control commercial mask. In addition, the mask with EHL-AA-x could prevent the adhesion of bacteria by the formation of anionic and cationic hydration layers. Using this strategy, ideal lignin-based antimicrobial materials with good bacteriostatic activity and anti-bio-adhesion properties could be designed and used in personal protection equipment. [ABSTRACT FROM AUTHOR]

Lignin‐based nanomaterials fabricated by solution self‐assembly in organic–aqueous solvent mixtures are among the most attractive biomass‐derived products. To accurately control the structure, size, and properties of lignin‐based nanomaterials, it is important to achieve fundamental understanding of its dissolution and aggregation mechanisms. In this work, atomic force microscopy (AFM) and molecular dynamics (MD) simulations are employed to explore the dissolution and aggregation behavior of enzymatic hydrolysis lignin (EHL) in different organic–aqueous solvent mixtures at molecular scale. EHL was found to dissolve well in appropriate organic–aqueous solvent mixtures, such as acetone–water mixture with a volume ratio of 7:3, whereas it aggregated in pure water, ethanol, acetone, and tetrahydrofuran. The interactions between the EHL‐coated AFM probe and the substrate were 1.21±0.18 and 0.75±0.35 mN m−1 in water and acetone, respectively. In comparison, the interaction decreased to 0.15±0.08 mN m−1 in acetone–water mixture (7:3 v/v). MD simulations further indicate that the hydrophobic skeleton and hydrophilic groups of lignin could be solvated by acetone and water molecules, respectively, which significantly promoted its dissolution. Conversely, only the hydrophobic skeleton or the hydrophilic groups were solvated in organic solvent or water, respectively, inducing serious aggregation of lignin. [ABSTRACT FROM AUTHOR]

Owing to its high aromaticity and carbon content, technical lignin as the by-product of chemical pulping and bio-refining industry can be converted into lignin-derived porous carbon (LPC) materials after activation, which is a promising strategy for high-value utilization. In particular, LPC with a higher surface area and graphitization will have a broad prospect as the electrode material for lithium-ion batteries (LIBs). However, the structure of technical lignin varies greatly due to its different industrial processes and botany sources, which remarkably affects the activation process and electrochemical properties of LPC. Herein, we study the effect of oxygen/carbon (O/C) ratio and molecular weight on the structure of LPC by exploring the effect of four kinds of technical lignin on K2CO3 activation. High O/C ratio can promote LPC to maintain a high specific surface area (SSA). High molecular weight and low O/C ratio were beneficial to increase the graphitization degree and keep the porous structure of LPC. The electrochemical performance evaluation showed that high graphitization and stable porous structure were beneficial for lithium-ion storage. Therefore, LPC from enzymatic hydrolysis lignin (EHL) had long cycle performance (490 mAh · g−1 at a current density of 400 mA · g−1) and excellent rate performance compared to lignin from chemical pulping. [ABSTRACT FROM AUTHOR]

Lignin is the most abundant by-product from the pulp and paper industry as well as the second most abundant natural renewable biopolymer after cellulose on earth. In recent years, transforming unordered and complicated lignin into ordered and uniform nanoparticles has attracted wide attention due to their excellent properties such as controlled structures and sizes, better miscibility with polymers, and improved antioxidant activity. In this review, we first introduce five important technical lignin from different sources and then provide a comprehensive overview of the recent progress of preparation techniques which are involved in the fabrication of various lignin-based nanoparticles and their industrial applications in different fields such as drug delivery carriers, UV absorbents, hybrid nanocomposites, antioxidant agents, antibacterial agents, adsorbents for heavy metal ions and dyes, and anticorrosion nanofillers. [ABSTRACT FROM AUTHOR]

• Utilizing aminated lignin as a precursor for N-doping modification of Ni. • The charges redistribution between Ni and NC carriers endows superior performance. • DFT unveils the energy barrier of ethanol coupling reaction on the Ni-N-C site. • N-doped engineering Ni for synthesis of higher alcohols from bioethanol. The selective conversion of biomass-derived ethanol into higher alcohols is a desirable but challenging process for the efficient production of value-added chemicals from alternative carbon sources. However, the current catalysts used in ethanol coupling exhibit low conversion rates and yields towards the formation of higher alcohols, necessitating significant improvements in their efficiency for practical applications. In this work, a lignin-derived N-doped carbon- supported Ni catalyst for ethanol coupling was designed and synthesized. The Ni@NC catalyst, synthesized using diethylenetriamine as the nitrogen source with a mass ratio of nitrogen source to lignin of 2:1 and a molar ratio of metal to lignin of 20:1, demonstrated excellent performance, with an ethanol conversion rate of 81.1% and a yield of C 4+ alcohols reaching 35.3%. Experimental results and density functional theory (DFT) calculations suggest that nitrogen-doped lignin, in appropriate quantities, along with the metal active component, forms a Ni-N-C structure that controls charge redistribution between the support and the Ni catalyst. This structure hinders the interaction of reaction intermediates and inhibits the production of by-products in the decomposition reaction, resulting in a higher yield of C 4+ alcohols. This study presents a more cost-effective and efficient approach for developing ethanol-coupling catalysts and holds promise for expanding the utility of lignin-derived catalysts. [ABSTRACT FROM AUTHOR]

The inherent challenges posed by lignin, such as its high heterogeneity, complex structure and dark color, have impeded its widespread high-value utilization. In the present study, a green cosolvent system comprising ethanol (EtOH) and dimethyl carbonate (DMC) was employed for the fractional separation of alkali lignin. Through careful manipulation of the solvent ratio, interactions between the solvents and lignin were effectively regulated, leading to the reduction of lignin heterogeneity and the isolation of lignin fractions with distinct properties. Notably, a high yield of up to 35.65% of lignin with desirable characteristics, including a light color, low molecular weight, and high hydroxyl groups content, was achieved. Furthermore, this specific lignin fraction exhibited enhanced UV absorption and antioxidative properties, rendering it highly suitable for potential applications in sun protection products. When incorporated as micro-nano particles, it exhibited great compatibility with hand creams and elevated their sun protection factor (SPF). This innovative approach not only presents a green and straightforward lignin fractionation process but also highlights the untapped potential of lignin in the realm of sun protection applications. [Display omitted] • Lignin was fractionated by sequentially dissolving in a green ethanol/DMC cosolvent. • Lignin with light color showed enhanced UV absorption and antioxidant activity. • Light-color lignin nanoparticles were prepared and improved the SPF of hand cream. [ABSTRACT FROM AUTHOR]

• The ternary DES was used to deconstruct softwood. • DES (AlCl 3 -1,4-BDO-ChCl) has the best pretreatment effect. • The lignin has the lightest color with L* value of 77.9. • The lignin-blended sunscreen has an SPF of 26.95 ± 4.20. Lignin is the most abundant natural phenolic polymer. However, the severe condensations of industrial lignin resulted in an undesirable apparent morphology and darker color, which hindered its application in the field of daily chemicals. Therefore, a ternary deep eutectic solvent is used to obtain lignin with light-color and low condensations from softwood. The results showed that the brightness value of lignin extracted from aluminum chloride-1,4-butanediol-choline chloride at 100 °C and 1.0 h was 77.9, and the lignin yield was 32.2 ± 0.6%. It is important that 95.8% of β-O-4 linkages (β-O-4 and β-O-4′) was retained. Lignin is used to prepare sunscreens and is added to physical sunscreens at 5%, with SPF up to 26.95 ± 4.20. Meanwhile, enzyme hydrolysis experiments and reaction liquid composition tests were also conducted. In conclusion, a systematic understanding of this efficient process could facilitate high-value utilization of lignocellulosic biomass in industrial processes. [ABSTRACT FROM AUTHOR]

The marriage of AFM, QCM and computational simulation quantitatively offers in-depth understanding of cellulase interaction with lignin, toward achieving an economic production of biofuels. We found that the long-range hydrophobic interaction firstly captures protein from solution and decreases the distance between cellulase and lignin so that other short-range interactions play a role in stabilizing the non-productive adsorption. [Display omitted] • Lignin-enzyme interactions were unmasked using a combination of atomic force microscopy and computational simulations. • The temperature sensitivity of cellulase adsorption behaviors is largely due to the changes in hydrophobic interactions. • The contribution of different long-range and short-range forces was revealed. • Hydrophobic interactions, hydrogen bonding, and steric effects drive the final adsorption capacity and glucose yields. Quantitatively understanding of interaction mechanism between lignin and cellulases is essential for the efficient improvement of lignocellulose enzymatic hydrolysis. However, the individual contribution of multiple forces between lignin and cellulases to the non-productive adsorption of enzymes still remains deeply ambiguous, especially in situations of near enzymatic hydrolysis temperatures. Herein, atomic force microscopy (AFM) and computational simulations were utilized to quantitatively analyze the intermolecular forces between lignin and enzyme at 25 °C and 40 °C. Our results unveiled that an increase in temperature obviously improved adsorption capacity and total intermolecular forces between lignin and cellulases. This positive relationship mainly comes from the increase in the decay length of hydrophobic forces for lignin-cellulases when temperature increases. Different from the hydrophobic interaction which provides long-range part of attractions, van der Waals forces dominate the intermolecular force only at approaches < 2 nm. On the other hand, electrostatic forces exhibited repulsive effects, and its intensity and distance were limited due to the low surface potential of cellulases. Short-range forces including hydrogen bonding (main) and π-π stacking (minor) stabilize the non-specific binding of enzymes to lignin, but increasing temperature reduces hydrogen bond number. Therefore, the relative contribution of long-range forces increased markedly at higher temperatures, which benefits protein capture and brings lignin and cellulase close together. Finally, the structure–activity relationships between lignin physicochemical properties and its inhibitory effect to enzymes indicated that hydrophobic interactions, hydrogen bonding, and steric effects drive the final adsorption capacity and glucose yields. This work provides quantitative and basic insights into the mechanism of lignin-cellulase interfacial interactions and guides design of saccharification enhancement approaches. [ABSTRACT FROM AUTHOR]

[Display omitted] Super-hydrophilic/underwater super-oleophobic materials composed of biomass show great advantages for the treatment of oily wastewater due to their inherent fouling resistance. However, the development of three-dimensional materials from biomass for oil–water separation is still a challenge. It is universally acknowledged that constructing a rough structure on the surface of hydrophilic substrates would significantly improve the underwater oleophobicity and oil–water separation performance. In this work, a three-dimensional lignin/cellulose aerogel (LCA) was developed through sol–gel method with freeze-drying. The rough microstructure and 3D interconnected network composed of lignin and cellulose impart excellent underwater superoleophobicity to LCA for efficient oil–water separation. The introduction of lignin to cellulose aerogel could effectively enhance its surface roughness, water permeation speed and underwater oil contact angle. Especially, the swelling properties of the hydrogel could be regulated by modulating the content of lignin, which could further control the pore size of aerogels to optimize the separation flux. The as-prepared aerogel showed remarkable performance in separating various oil–water mixtures and oil-in-water emulsions, with a separation flux of 7646 ± 167 L·m−2·h−1 and oil rejection rate >99 %. These excellent properties combined with its facile fabrication make LCA a promising candidate for the treatment of oily wastewater. [ABSTRACT FROM AUTHOR]

This work demonstrates an organic solvent fractionation method for lignin homogenization, which can effectively reduce the lignin heterogeneity and use each lignin fraction to prepare polyurethane foams (PUFs) with excellent mechanical properties. Such fractions were fully characterized by GPC, NMR (31P, 2D-HSQC), FTIR, and TG to obtain a detailed description of the structures and properties. The properties of PUFs from each lignin fraction showed higher compatibility than that from unfractionated industrial lignin, as studied by morphology and DSC analysis. The improvement of compatibility between the fractionated lignin fractions and polyethylene glycol can effectively enhance the mechanical properties of the prepared PUFs. The hysteresis loss (43.10%–51.85%) and resilience (95.81%–98.81%) of the fractionated lignin polyurethane foams (LPUFs) were better than that from the unfractionated LPUFs (hysteresis loss 41.64%, resilience 94.67%) at the lignin content of 5%. Subsequently, the strong relationships between lignin structures and PUF properties were demonstrated in detail. The suggested approach provides greater possibilities to prepare LPUFs with tunable properties based on real industrial lignin fractions, rather than modified lignin. • Solvent fractionation method was proposed for lignin homogenization. • Excellent compatibility between lignin fractions and polyurethane foams was formed. • The structure of lignin fractions determined the properties of polyurethane foams. • Tunable polyurethane foams based on real industrial lignin fractions were developed. [ABSTRACT FROM AUTHOR]

Despite the widespread utilization of nano silver composites in the domain of catalytic hydrogenation of aromatic pollutants in wastewater, certain challenges persist, including the excessive consumption of chemical reagents during the preparation process and the difficulty in recycling. In this study, silver ions were reduced in-situ by taking advantage of the adsorptive and reducing capacities of hydroxyls and amino groups on lignin porous microspheres (LPMs) under mild ultrasonic conditions, and lignin porous microspheres loaded with silver nanoparticles (Ag@LPMs) were conveniently prepared. Ag@LPMs had excellent catalytic and cycling performances for p-nitrophenol (4-NP), methylene blue (MB) and methyl orange (MO). The 4-NP could be completely reduced to 4-AP within 155 s under the catalysis of Ag@LPMs, with a pseudo-first-order kinetic constant of 1.28 min−1. Furthermore, Ag@LPMs could still complete the catalytic reduction of 4-NP within 10 min after five cycles. Ag@LPMs with the particle size ranging from 100 to 200 μm conferred ease of recycling, and the porous structure effectively resolved the issue of sluggish mass transfer encountered during the catalytic process. At the same time, the binding force of nano silver and LPMs obtained by ultrasonic was stronger than that of heating, so the materials prepared by ultrasonic had better cycling performance. Silver ions concentration and pH value in the preparation process affected the catalytic performance of Ag@LPMs, 50 mmol/L Ag+ and pH value of 7 turned out to be the optimization conditions. [Display omitted] • Ag@LPMs were prepared conveniently by in-situ reduction of Ag+ upon lignin porous microspheres. • AgNPs obtained under mild ultrasonic conditions have strong binding force with lignin microspheres. • Ag@LPMs had excellent catalytic and cyclic properties for aromatic pollutants. • The large size of Ag@LPMs allowed them to be recycled through suction filtration. • The porous structure of Ag@LPMs accelerated the mass transfer rate in the catalytic process. [ABSTRACT FROM AUTHOR]

Synopsis: Lignin porous carbon/PANI composites were prepared via in- situ polymerization using lignin as carbon precursor. The PANI nanofibers interpenetrate the lamellar structure of lignin porous carbon, which endows high accessibility to ions and fast transfer for electrons, leading to the superior capacitance for the composite and the high energy density when assembled into supercapacitor. [Display omitted] Lignin porous carbons show good potential as carbon electrode materials for supercapacitors, but face the problem of low capacitance. Combining lignin porous carbons with polyaniline can achieve high capacitance. However, capacitance degradation resulting from the poor compatibility between lignin porous carbons and polyaniline has been the major obstacle for their application. In this work, three lignin porous carbons with different geometries were used as the hosts to anchor polyaniline for carbon/polyaniline composites via in- situ oxidative polymerization, and the compatibility between lignin porous carbons and polyaniline was investigated. It was determined the lamellar hierarchical lignin porous carbon with crumpled nanosheets can provide a large accessible surface area for the heterogeneous nucleation of aniline, which ensures uniform loading of interpenetrating polyaniline nanofibers. Benefiting from the interpenetrating conductive network and enhanced compatibility, the lamellar hierarchical porous carbon/polyaniline composite possesses a high capacitance of up to 643 F/g at 1.0 A/g and a sufficient capacitance of 390 F/g at 30.0 A/g. This work therefore provides design guidance for carbon hosts in high-performance supercapacitor composite electrodes. [ABSTRACT FROM AUTHOR]

This investigation focuses on the catalytic demethoxylation of alkylmethoxyphenols derived from lignin depolymerization, aiming to convert them with high selectivity into essential chemical intermediates, namely methoxy-free alkyl phenols. A silver-loaded iron-cobalt oxide (Ag/Fe-CoO x) nanocomposite catalytic system was developed, featuring a dual-active-site catalytic mechanism driven by a hydrogen-spillover effect that involves the activation of hydrogen at the metallic active site, while the support's secondary site serves as the reaction locus for the substrates. It was revealed that by integrating iron into cobalt oxide nanosheet supports, catalyst activity and selectivity were finely tuned, particularly to enhance the production of demethoxylated phenols. With the optimized Ag/Fe-CoO x catalyst, a 99.7 % conversion of 4-propylguaiacol and a 94.1 % selectivity for 4-propylphenol were achieved, indicating effective reductive demethoxylation at 280°C and 0.4 MPa H 2. The fine structure of the support significantly affects demethoxylation selectivity, guiding the development of selective catalyst design in biomass conversion. [Display omitted] • Ag/Fe-CoO x enhances H 2 spillover for efficient demethoxylation of lignin phenols. • Dual-active-site mechanism and Fe doping are critical for selective control. • Achieves 99.7 % 4-propylguaiacol conversion, 94.1 % selectivity at 280°C, 0.4 MPa H 2. • Ag/Fe-CoO x achieves 94.7 % selective demethoxylation of birch lignin oil. [ABSTRACT FROM AUTHOR]

The characteristics of multi-hydroxyl structure and strong hydrogen bonding in polyvinyl alcohol (PVA) make its melting point close to its decomposition temperature, causing melt-processing difficulty. In this work, following the plasticization of small-molecule primary plasticizer acetamide, lignin was demonstrated as a green secondary plasticizer in realizing the melt processing and simultaneous reinforcement of PVA. During the plasticization process, lignin was able to combine with the hydroxyl groups of PVA, so as to destroy the hydrogen bonds and regularity of the PVA chains. The synergistic plasticization effect of lignin dramatically reduced the melting point of PVA from 185 °C to 151 °C. The thermal processing window of PVA composites was expanded from 50 °C to roughly 80 °C after introducing lignin. In contrast to acetamide, the addition of lignin significantly increased the tensile strength and Young's modulus of the composites to 71 MPa and 1.34 GPa, respectively. Meanwhile, lignin helped to hinder the migration of acetamide via hydrogen bonds. With the addition of lignin, the composites also displayed enhanced hydrophobicity and excellent UV shielding performance. The strategy of synergistic plasticization of lignin provides a feasible basis for the practical application of lignin in melt-processable PVA materials with good comprehensive properties. • Lignin was introduced as a green secondary plasticizer to realize the melt processing and reinforcement of PVA. • Lignin could destroy the hydrogen bonds of PVA chains and dramatically reduce the melting point of PVA. • Lignin served as physical cross-linking points to increase the tensile strength and Young's modulus of the PVA composites. • The composites also displayed low plasticizer migration, enhanced hydrophobicity and excellent UV shielding performance. [ABSTRACT FROM AUTHOR]

Nano silica (SiO 2) is usually used as a common reinforcing agent in polymer materials, in which the interfacial interaction greatly affects the mechanical properties of the composites. The reinforcement effect of silica on non-polar polymer is restricted due to their poor compatibility. In this work, amphipathic lignin modified by quaternization and alkylation was used as a modifier for silica to prepare hydrophobic lignin/SiO 2 nanoparticles by in-situ one-pot co-precipitation method. In alkaline solution, hydrophobic lignin and SiO 2 (from Na 2 SiO 3) were self-assembled to form nanospheres through electrostatic and hydrophobic interactions. The results showed that the lignin/SiO 2 nanoparticles were highly hydrophobic nanospheres with macropores in the surface. When the lignin/SiO 2 nanoparticles (10 wt%) were added to reinforce high-density polyethylene (HDPE), the mechanical properties of HDPE were improved with the strength of 24.5 MPa and the elongation of 1096%, which were increased by 10.4% and 14.3% compared with the control HDPE, because of the good compatibility and large bonding area. This work puts forward a new solution for the application of lignin in reinforcement of non-polar polymers. • Lignin was modified by quaternization and alkylation to obtain amphiphilicity. • Hydrophobic lignin/SiO 2 nanocomposites were prepared by in-situ one-pot co-precipitation method. • Lignin and SiO 2 were self-assembled to form nanospheres through electrostatic and hydrophobic interactions. • HDPE was reinforced by lignin/SiO 2 nanocomposites because of the good compatibility and large bonding area. [ABSTRACT FROM AUTHOR]

Lignin-based silver nanoparticles have been considered a promising antimicrobial material. However, it remains challenging to prepare ultra-small size silver nanoparticles sustainably with superior antibacterial performance. In this work, we modified ethanol-extracted lignin (EL) with carboxymethyl groups and further synthesized ultra-small particle size (3.8 ± 0.1 nm) nanosilver incorporated carboxymethyl lignin complexes (AgNPs@CEL) using ultrasonic technology. Due to the outstanding antibacterial properties of the ultra-small size nanosilver, AgNPs@CEL could cause 5.3 and 5.4 log 10 CFU/mL reduction against E. coli and S. aureus in 5 min. Meanwhile, AgNPs@CEL exhibited remarkable photothermal antibacterial performance, which caused 6.2 and 6.1 log 10 CFU/mL reduction of E. coli and S. aureus , with NIR irradiation for 5 min. Furthermore, the composite films prepared by doping only 0.5 wt% AgNPs@CEL into ethyl cellose could achieve a bactericidal rate more than 99.99 %. This study provides a new insight into design of controlled particle size lignin-based antibacterial nanosilver materials in a sustainable manner and holds promise for applications in antibacterial fields. Construction of lignin-based ultrasmall nanosilver complexes for efficient photothermally mediated sterilization. [Display omitted] [ABSTRACT FROM AUTHOR]

The conventional fractionation of lignocellulose is generally carried out at high temperatures, high acid or alkali, or using organic solvents due to the rigid matrix of lignocellulose and crystallinity of cellulose, leading to the condensation of lignin and environmental pollution, and hindering the further value-added utilization of lignin. In this work, a rapid fractionation method was proposed, in which hemicellulose and cellulose (holocellulose) were first dissolved and partially hydrolyzed in acidified LiCl molten salt hydrates, followed by a filtration process to isolate the lignin solid with a purity of 88.3%. It was found that the dissolution of holocellulose required the addition of a small amount of acid to break the cellulose chain into short chains. Due to the small amount of acid added and the rapid dissolution, the obtained lignin has as high as 89.5% of β-O-4 bond content close to the theoretical value, suggesting that a promising native lignin structure was preserved. The isolated lignin can be selectively depolymerized into monophenol over Ru/C catalyst with a high yield of 24.2%. In addition, the dissolved holocellulose without containing lignin was selectively hydrolyzed into sugars in acidified LiCl molten salt hydrates, giving 63.1% of xylose, 43.9% of glucose, 29.5% of xylan oligomers, and 48.2% of glucan oligomers, respectively. [Display omitted] • LiCl molten salt hydrates required little acid to dissolve holocellulose. • LiCl-AMSH could quickly dissolve holocellulose and separate noncondensed lignin. • 88.3% purity of noncondensed lignin was fractionated. • 24.2% of monophenol (88.0% to theoretical) was obtained from noncondensed lignin. • 63.1% of xylose, 43.9% of glucose, 29.5% of xylan oligomers, and 48.2% of glucan oligomers were obtained. [ABSTRACT FROM AUTHOR]

In this study, a porous polyamine lignin microsphere (PPALM) was prepared through the inverse suspension polymerization combined with freeze-drying, during which sodium lignosulfonate and polyetheramine (PEA) were crosslinked with epichlorohydrin (ECH) as the cross-linker. By adjusting the amount of ECH and PEA, the optimized PPALM exhibited suitable crosslinking degree, ensuring a balance of framework flexibility and rigidity, thereby facilitating the formation of abundant and fine pores. PPALM demonstrated good mechanical properties comparable to commercial sulfonated polystyrene cationic resin, with a porosity of 61.12 % and an average pore size of 283.51 nm. The saturation adsorption capacity of PPALM for Pb2+ was measured to be 156.82 mg/g, and it remained above 120 mg/g after five cycles of regeneration. Particularly, the concentration of 50 mg/L Pb2+ solution could be reduced to 0.98 mg/L after flowing through the PPALM packed bed, indicating the great potential of PPALM for application in wastewater treatment. [Display omitted] • Lignin was crosslinked with polyetheramine by epichlorohydrin to achieve suitable flexibility and rigidity, and a porous lignin microsphere (PPALM) was further prepared through inverse suspension polymerization. • PPALM has abundant pore structure and a saturated adsorption capacity for Pb2+ of 156.82 mg/g, which is superior to reported lignin microspheres. • Thanking to large size of 300–500 μm and excellent mechanical properties, PPALM overcomes the deficiencies of conventional lignin adsorbents and can be applied in bed/column adsorption. [ABSTRACT FROM AUTHOR]

The synthesis of carboxylic acid compounds by the selective electrooxidation cleavage of the C(OH)-C bond in lignin is significant to biomass conversion to produce high-value-added chemicals. However, it is challenging to selectively cleave the C(OH)-C bond due to its extremely high dissociation energy of 260–300 kJ mol−1. Herein, a simple and effective method of hydrothermal process and wet impregnation is proposed to synthesize Pt@CeO 2 catalysts. The cleavage of the C(OH)-C bond by Pt@CeO 2 , a catalyst loaded with a small amount of noble metal, triggered the electrochemical oxidation of lignin, resulting in the highly selective synthesis of carboxylic acid compounds. Consequently, more reactive oxygen species (ROS) are produced in the electrocatalytic oxidation process, which enhances the cleavage of C(OH)-C bond and the oxidation of benzaldehyde. In addition, Pt@CeO 2 can also be used for the electrochemical depolymerization of industrial alkali lignin to produce carboxylic acids. This research proposes an efficient way of producing carboxylic acids of high value by utilizing an electrocatalyst for the electrocatalytic oxidation of lignin. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel strategy for enhancing the photothermal conversion performance of lignin was proposed. • The mechanism of the photothermal performance enhancement of lignin is clarified. • A double-layer biomass aerogel evaporator is prepared using lignin as a photothermal agent. • The 4DAGS shows outstanding evaporation performance, reaching an evaporation rate as high as 5.911 kg/(m2∙h) under 3 sun. • The 4DAGS exhibited superior salt-reject performance and acid and alkali resistance. The undesirable photothermal conversion performance of lignin limits the potential for directing use as a photothermal conversion material, and no strategies have been found to enhance the photothermal conversion efficiency of lignin. Herein, three modified lignin of corn stover alkali lignin (DEHL), pine alkali lignin (DAL) and birch alkali lignin (DTAL) with excellent photothermal conversion efficiency and fast temperature response was prepared by a one-step iodocyclohexane (ICH) activation strategy. The maximum temperature of the DEHL, DAL and DTAL can reach to 138 °C, 157 °C, and 172 °C in 12 min under 0.15 W/cm2 compared to the native lignin. Moreover, the photothermal conversion efficiency of the DEHL, DAL and DTAL was calculated to be 36.52 %, 36.19 % and 43.19 % by ICH modification. The photothermal enhancement mechanism of the modified lignin was determined by various characterizations and simulation calculations, which can be summarized that the activation of lignin by ICH breaks the molecular structure and reduces the methoxy content of the lignin, which enhances the intermolecular bonding, and the hydrogen bonding between the phenolic hydroxyl groups strengthens the π-π intermolecular interactions between the benzene rings. In addition, a double-layer biomass aerogel evaporator (DAGS) with cost-friendly and superior evaporation performance was synthesized by chemical cross-linking using DTAL as the photothermal agent. The evaporation rate of 4DAGS can be as high as 2.063, 2.024, 2.259 and 2.447 kg/(m2∙h) in water, 3.5 wt% seawater, and 200 mg/L of MG or MB wastewater under 1sun. And no salt was observed on the surface of the 4DAGS after a long period of 36 h of operation in 3.5 wt% seawater, suggesting the outstanding salt-reject performance of the aerogel. Furthermore, there is no structural damage and chemical decomposition found on 4DAGS after 24 h immersion in NaOH and HCl solutions, demonstrating the excellent acid and alkali resistance of the synthesized aerogels. This work may offer a novel strategy for the photothermal performance enhancement of lignin and expand the potential application in solar-driven evaporation materials. [ABSTRACT FROM AUTHOR]

It is of significance to efficiently convert renewable and sustainable lignin bio-oil into cyclohexanol and its derivatives by selective hydrodeoxygenation to alleviate excessive dependence on fossil resources. However, the complicated components of lignin bio-oil hindered its application as bulk chemicals. A bimetallic Ni-Co catalyst supported on MgO-modified γ-Al 2 O 3 was constructed for the catalytic hydrodeoxygenation of monophenolics from lignin bio-oil. The bimetallic catalyst with adding Co increased active centers and acid sites, improving the catalytic activity to the hydrodeoxygenation, compared to the Ni-based catalyst. The proper addition of MgO into the catalyst carrier increased the interplay among the Ni, Co particles and the catalyst carrier owing to the electron transfer from MgO into Ni and Co species. The enhanced interplay between active metal particles and the catalyst carrier benefited the dispersion of Ni, Co particles, and the average Ni and Co particle size decreased from 14 nm to 10 nm. Furthermore, MgO increased the basic sites, which effectively inhibited the elimination of the hydroxyl groups in phenols and preserved hydroxyl groups, resulting in a significant improvement in the selectivity of cyclohexanol and its derivatives. Ni-Co/Al 2 O 3 -MgO with good cycling stability contributed to a 65.6 wt% yield of cyclohexanol and its derivatives when the hydrodeoxygenation of monophenolics (such as guaiacol, 2,6-dimethoxyphenol and their alkyl substitutes) was pursued in isopropanol at 300 ℃ and 2 MPa H 2 for 5 h. It was found that excessive dosage of the catalyst, higher temperature and hydrogen pressure, as well as longer reaction time, caused the excessive hydrodeoxygenation of monophenolics and hence decreased the selectivity to cyclohexanol and its derivatives. This work might provide a new idea for the high-value utilization of lignin bio-oil. ● Selective hydrodeoxygenation of monophenolics was carried out over Ni-Co/Al 2 O 3 -MgO. ● Adding Co increased active centers and acidic sites, improving catalytic activity. ● The addition of MgO enhanced both the metal-support interaction and basic sites. ● Basic sites decreased the cleaving ratio of the C-OH bonds, and hence increased selectivity. ● Ni-Co/Al 2 O 3 -MgO contributed 65.6 wt% yield of cyclohexanol and its derivatives from monophenolics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Oxygen vacancies induced by Ce doping mediate the formation phase transition rearrangement of δ-Bi 2 O 3 to form tetragonal phase Bi 2 O 2.75. • In-situ reduction of Bi3+ produces Bi0 to prepare S-type heterojunction Bi0/Bi 2 O 3 /Bi 2 O 2.75 ultrathin nanosheets. • The S-type charge transfer mechanism of Bi0/Bi 2 O 3 /Bi 2 O 2.75 heterojunction has been analyzed through experiments and DFT calculations. Fluorite bismuth oxide (δ-Bi 2 O 3) has been extensively investigated in the fields of environmental and energy photocatalysis, owing to its exceptional charge transport performance and remarkable resistance to photocorrosion. However, the limited absorption spectrum of light and rapid recombination of photogenerated charge results in a low quantum efficiency. Herein, abundant oxygen vacancies Bi0/Bi 2 O 3 /Bi 2 O 2.75 ultrathin nanosheets materials with a thickness of approximately 4.8 nm are constructed by Ce doping. It is shown that doping Ce in Bi 2 O 3 lattice can generate oxygen vacancies, which induces phase transition rearrangement of δ-Bi 2 O 3 to form tetragonal phase Bi 2 O 2.75 locally, and finally forming Bi 2 O 3 /Bi 2 O 2.75 heterojunction. In addition, the addition of Ce in the solvothermal process inhibits the conversion of Bi3+ to bismuth at high temperature, making the content of each component in the Bi0/Bi 2 O 3 /Bi 2 O 2.75 heterostructure controllable. The optimized Bi0/Bi 2 O 3 /Bi 2 O 2.75 catalyst exhibits excellent performance in visible light catalytic degradation of lignin, owing to the synergistic effect of high specific surface area, Bi plasma resonance effect and charge mobility. The degradation rate is approximately 35.0 times and 30.6 times higher than that of pure Bi 2 O 3 and non-doped Bi/Bi 2 O 3 , respectively. Both the formation mechanism and S-type charge transfer mechanism of Bi0/Bi 2 O 3 /Bi 2 O 2.75 heterojunction have been deeply analyzed through experimental investigation and DFT theoretical calculations. [ABSTRACT FROM AUTHOR]

• The iodine-doped strategy is used to regulate band structure of Bi 2 O 2 CO 3 for molecular oxygen activation. • In-situ reduction of Bi3+ produces the noble metal-like catalysis Bi0 to prepare Bi/5I-Bi 2 O 2 CO 3 ultrathin nanosheets. • Simultaneous manipulation of Bi 2 O 2 CO 3 energy band regulation and Bi loading for promoting the separation of photogenic carriers. • The Bi/5I-Bi 2 O 2 CO 3 shows excellent photocatalytic activity for photodegradation of organism. • The degradation pathway and mechanism of vanillin were proposed. The photocatalytic efficiency of Bi 2 O 2 CO 3 is greatly limited by rapid recombination of photogenerated carriers. This is due to the fact that the conduction potential cannot meet the generation potential of superoxide radical, the accumulation of electrons accelerates its recombination with holes. Hence, I- doping strategy is used to regulate the energy band of Bi 2 O 2 CO 3 to improve the reduction ability of valence band electrons to molecular oxygen, promote the efficient use of superoxide radicals and photogenerate holes in the degradation of pollutants. In addition, the solvent ethylene glycol in-situ reduces Bi3+ to Bi0, the tiny Bi0 particles are deposited onto BOC sheets, serving as cocatalysts similar to precious metals and enhancing the separation and transfer of photogenerated carriers. The results indicate that I-doping leads to a decrease in the work function of Bi 2 O 2 CO 3 and an upward shift of the conduction band, which enhances the activation of molecular oxygen and the generation of superoxide radicals. The formation of Bi0/5I-Bi 2 O 2 CO 3 not only promotes surface reaction, but also expands light absorption. The Bi0/5I-Bi 2 O 2 CO 3 shows excellent photocatalytic activity for photodegradation of organism. After 60 min exposure to simulated sunlight, the UV–vis absorption peak of lignin at 280 nm disappeares completely, and the mineralization rate reaches 48.9 %. Rhodamine B only needs 1 min to completely fade. Where, vanillin is used as a lignin model, its degradation intermediates are determined by LCMS, and the possible photodegradation pathway is proposed in detail. [ABSTRACT FROM AUTHOR]

The complex chemical structure and broad molecular weight distribution of lignin lead to heterogeneity and unsatisfactory performance, essentially restricting its high-value utilization. A novel lignin fractionation process is proposed here to solve this problem and overcome the shortcomings of common fractionation methods. Using enzymatic hydrolysis lignin (EHL) as raw material, five lignin fractions were obtained by cooling precipitation in the ethanol/water mixed solvent. Their chemical structure and physicochemical properties were compared. All lignin fractions presented reduced heterogeneity compared to the EHL and a gradual decrease of molecular weights accompanied by increasing hydrophilic group content. In addition, temperature-induced self-assembly for forming lignin colloidal spheres co-occurred during cooling precipitation. Interestingly, a fraction with light color and high UV-blocking activity was obtained. By combining this color-light sample with pure hand cream, a lignin-based sunscreen was prepared, which had a 40 % higher sun protection factor (SPF) than EHL sunscreen. [Display omitted] • Lignin fractions were obtained by step cooling precipitation. • Lignin colloidal spheres were formed by temperature-induced self-assembly. • A lignin fraction with light color and strong anti-ultraviolet could be obtained. [ABSTRACT FROM AUTHOR]

High-yield noncondensed lignin and cellulose possessing high enzymatic digestibility can be obtained using p -toluenesulfonic acid in methanol under microwave irradiation. [Display omitted] • 87.9% of noncondensed lignin with ether bonds preserved was obtained. • 42.0% of monophenol (74.9% to theoretical) obtained from noncondensed lignin. • 94.3% of enzymatically digestible cellulose was isolated. • Microwave irradiation facilitated lignin-carbohydrate complex bonds cleavage. • The α-methoxylation by methanol inhibited condensation of extracted lignin. Production of noncondensed lignin via lignocellulose fractionation usually shows limited yield. Promoting reaction conditions benefits lignin production but has negative effect on structural condensation and thus inhibits its value-added applications in depolymerization. To address this issue, a unique fractionation method was proposed using p -TsOH (p -toluenesulfonic acid) in methanol under microwave irradiation to produce high-yield noncondensed lignin. It was found that microwave irradiation efficiently decreased the activation energy of lignin-carbohydrate complex (LCC) bonds cleavage from 102.1 to 63.8 kJ/mol and thereby facilitated lignin exfoliation from carbohydrates. And an effective α-alkoxylation reaction occurred between methanol molecular and C α -OH group in lignin, which protected β -O-4 linkages from condensation. After being fractionated under a relatively mild fractionation condition of 85 ℃ for 30 min, a promising lignin yield of 87.9 % can be obtained from poplar sawdust, with 91.8 % of ether bonds preserved. The obtained lignin can be selectively depolymerized into monophenols with a high yield of 42.0 %, which was 74.9 % to the theoretical yield. Besides, 94.3 % of cellulose was retained in solid part after fractionation, which can be efficiently converted into glucose with a yield of 98.5 % via enzymatic hydrolysis. [ABSTRACT FROM AUTHOR]

• Lignin-derived hierarchical porous carbon was fabricated via a novel method. • LPC-CaCO 3 has a high surface area and large numbers of interconnected pores. • Uniform precursor and pyrolysis process are essential to the structure of LPC-CaCO 3. • LPC-CaCO 3 shows superior adsorption capacity to antibiotics than most adsorbents. Biomass-derived porous carbon is a promising antibiotic adsorption material due to its abundant reserves, low cost, and eco-friendly features. However, most biomass-derived porous carbon exhibits undesirable performance in the adsorption of high-molecular-weight antibiotics, which is attributed to the large mass transfer resistance during the adsorption process. Herein, we employ lignosulfonate (LS) as the biomass carbon source and CaCO 3 as the activator to fabricate lignin-derived hierarchical porous carbon (LPC-CaCO 3) which possesses a high surface area (2944 m2/g) and a large pore volume (1.406 cm3/g). Moreover, we demonstrate uniform mixing and simultaneous pyrolysis of carbon resources and activators are essential to the formation of interconnected pores. Large numbers of connected pores effectively reduce the mass transfer resistance. LPC-CaCO 3 exhibits high adsorption capacity to low-molecular-weight antibiotics (sulfamethazine) and high-molecular-weight antibiotics (tylosin) in both batch and column modes. The adsorption performances of LPC-CaCO 3 to antibiotics, especially high-molecular-weight antibiotics, are superior to most other reported biomass-derived carbons, commercial activated carbons, and petroleum-derived carbons. This work presents an effective strategy to fabricate a high-performance antibiotics adsorbent from biomass resources and provides deep insight into the structure–activity relationship of porous antibiotics adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] Cellulase was recycled by using pH-UCST-type LSB, and the process is sustainable while realizing the value-added utilization of industrial lignin. • LSB showed a pH-UCST-sensitive response and was recyclable. • Cellulase was efficiently recycled at higher pH by using LSB. • The value-added utilization of enzymatic hydrolysis lignin was realized. Recycling cellulase can reduce the cost of lignocellulosic enzymatic hydrolysis. Here, a lignin-grafted sulfobetaine (LSB) was first synthesized by grafting sulfobetaine (SB) on enzymatic hydrolysis lignin (EHL). LSB had a sensitive response of pH and temperature. LSB dissolved under the conditions of lignocellulosic enzymatic hydrolysis (pH 5.0, 50 °C). After hydrolysis, LSB co-precipitated with cellulase when lowering pH of the hydrolysate to 4.0 and cooling to 25 °C. When 3.0 g/L LSB-100 was added to the hydrolysis system of corncob residue (CCR), 70 % of amount of cellulase was saved. LSB had a remarkable response and stronger cellulase recovery capacity. This was attributed that carboxylate radical in LSB was protonated, and positive and negative ions of SB associated to form salt at 25 °C. This work provides a new idea for reducing the cost for preparing fermentable sugars from lignocellulose, and increasing the added value of EHL. [ABSTRACT FROM AUTHOR]

[Display omitted] • Indium sulfide with indium defects and hydrophobic surface is prepared. • Defect is important for the induction of CTAB. • The hydrophobic indium sulfide enhances the adsorption of lignin and oxygen. • In x S 3 -C exhibits good activity under low visible light (80 mW⋅cm−2, 5 W LED). • The degradation pathway of lignosulfonate was proposed by HPLC-MS. Lignin is difficult to be degraded due to its complex structure and hydrophobicity. Herein, we report an effective strategy to degrade lignin by defective indium sulfide with the hydrophobic surface (In x S 3 -C). In x S 3 -C is synthesized by a one-pot hydrothermal method with the assistance of CTAB. The optimal photocatalyst (In 0.75 S 3 -C) exhibits great adsorption capacity and degradation efficiency for lignosulfonate. The degradation rate of lignosulfonate achieves 90% after irradiating by visible light for 30 min, representing nearly 80 times higher activity than the commercial photocatalyst (P25). The great photocatalytic performance of In 0.75 S 3 -C is ascribed to the enhanced adsorption of lignosulfonate and oxygen, which facilitates intimate contact and mass transfer. Furthermore, TG-DSC, FTIR, UV–vis DRS and TRPL demonstrate that the defects are important for the introduction of CTA+, as well as enhance visible light absorption and the separation of photogenerated carriers. Combined with HPLC-MS analysis, a possible degradation pathway of lignosulfonate is proposed. [ABSTRACT FROM AUTHOR]