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The development of self-powered UV photodiode on green substrate is still a challenge. In this study, highly conductive Al doped ZnO (AZO) film was sputter-deposited on paper substrate at room temperature; subsequently, paper-based Schottky photodiodes were successfully fabricated by following Au-ZnO-Al and Au-ZnO-AZO-Al structure designs, respectively. These UV light-based devices operate successfully without external power. Au-ZnO-AZO-Al photodiode shows improved response and faster speed compared to Au-ZnO-Al photodiode. The one-dimensional Poisson simulation results demonstrate that the improvement is attributed to the strong electric field in the ZnO-AZO n-n+ high-low junction, thus, enhancing the collection rate and drifting speed of the photogenerated carriers. In addition, AZO can form favorable ohmic contact with the Al electrodes, further improving the device performance. The photo-response of the paper-based photodiode device shows high reproducibility and stability. Based on these outstanding results, we conclude that these paper-based electronic devices have great potential to replace conventional petroleum-based flexible electronic devices, thus, contributing to the green/sustainable development. [ABSTRACT FROM AUTHOR]

The high‐efficiency conversion of water drop mechanical energy into electrical energy has always been an urgent issue in the development and utilization of raindrop energy. In this work, a novel drum‐like triboelectric nanogenerator (D‐TENG) with robust self‐cleaning superhydrophobic features is developed to harvest water drop energy. An elastic superhydrophobic cellulose paper is created by spray‐coating nanofumed silica dispersed in a thermoplastic elastomer solution, followed by treatment with triethoxy‐1H,1H,2H,2H‐tridecafluoro‐n‐octylsilane. When raindrops hit the D‐TENG surface, the superhydrophobic cellulose paper will vibrate and periodic contact and separation with polytetrafluoroethylene will occur to generate electricity. The results demonstrate that when a 6 mm water drop falls from a height of 2.5 m and hits the D‐TENG, the generated voltage output can reach a peak of 21.6 V and charge transfer of 10 nC. The output power of the D‐TENG can reach 16 µW per droplet, which is more than 13.3 times that generated from the previous TENGs based on the electrostatic induction of water droplets. These results indicate that the superhydrophobic cellulose paper‐based D‐TENG is potentially a strong candidate for harvesting energy from raindrops, thereby making it a promising sustainable energy source for next‐generation electronics. [ABSTRACT FROM AUTHOR]

Highlights • Chlorine dioxide demand could be saved by 20% ∼ 33% through removal of 54.7% ∼ 76.6% hexenuronic acid. • Kappa number and brightness reversion could be improved. • AOX could be decreased by 50%, TOC and COD could be increased by 22% and 73% with D-hot. • Kinetic for hexenuronic acid degradation in D-hot is proposed. Abstract In this study, the effects of the hemicellulose-linked hexenuronic acid (HexA) on the kappa number, brightness reversion and effluent properties under the hot chlorine dioxide bleaching (D-hot) stage were investigated. Moreover, the effects of the chlorine dioxide content on the residual HexA of bagasse pulp in D 0 and D-hot stage was evaluated. HexA was determined by UV–vis, and the absorbable organic halogen (AOX), chemical oxygen demand (COD) and total organic carbon (TOC) in the bleached effluent were analyzed by using the AOX analyzer, COD analyzer and TOC analyzer, respectively. The results showed that the amount of chlorine dioxide could be reduced by D-hot pretreatment. The kappa number and brightness reversion of the bleached pulp obviously improved. Compared to the control, the AOX content decreased dramatically with an increase in temperature. However, the COD and TOC increased significantly. A kinetic model considering the removal of hexenuronic acid and its degradation was proposed. Degradation reactions of hexenuronic acid are first-order with respect to their content, and the pH influences the degradation of hexenuronic acid. The activation energy is 2.23 kJ/mol when the pH is 3.2, indicating that the degradation of hexenuronic acid is very rapid under these conditions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Enzyme and cold alkali assisted mechanical production of CNF was studied. • Thermal stability of CNF will be affected by cellulose crystalline structure. • Presence of hemicellulose in CNF improves their thermal stability. • Presents new avenues for research on CNF-based electronic devices. Abstract Lignocellulosic biomass is the most abundant renewable resource on the earth. With the development of related fields, the high value utilization of lignocellulosic biomass has gradually become a new avenue for research. In this study, unbleached bagasse pulp was pretreated with xylanase and cold alkali to partially remove hemicellulose and convert to some cellulose I into cellulose II. Cellulose nanofibrils (CNF) were then obtained through ultra-micro grinding and high-pressure homogenization. The prepared CNF were characterized by TEM, Zeta potential, ATR-FTIR and XRD, and a thermogravimetric analyzer was used to analyze the thermal stability of CNF. The results show that xylanase pretreatment can improve the dispersion of fibers during mechanical treatment and can enhance the crystallinity of CNF. With an increase in alkali concentrations, the proportion of cellulose II structures increased, while cellulose crystallinity levels decreased due to the folding of cellulose chains. Under the common influence of crystallinity and crystal structures, the thermal stability of the CNF prepared after cold alkali pretreatment underwent an increasing trend. This shows that the influence of crystal structures on the thermal stability of CNF gradually plays a dominant role as alkali concentrations increase. [ABSTRACT FROM AUTHOR]

In the present study, cellulose nanofibrils (CNF) were produced from unbleached eucalyptus pulp, and the effect of enzymatic treatment on the properties of CNF was studied. Moreover, the mechanism of enzymatic treatment on the dispersion and film properties of CNF was speculated. The xylanase pretreatment facilitated the deconstruction of pulp into CNF via mechanical shearing and high-pressure homogenization, while the hemicellulose composition was preserved. Compared to the control, the CNF suspensions made from the xylanase pretreated pulp were more crystalline with higher dispersion, optical and rheological properties. CNF films were produced with a vacuum filtration process. The optical and mechanical strength properties of the CNF films were improved by the removal of hemicellulose. It was found that the carboxyl and hydroxyl groups played key roles in affecting the dispersion and film properties of the CNF. The carboxyl group content increased after the enzymatic pretreatment, which benefits the even distribution of CNF in water. The mechanical strength of the CNF films was further improved by exposing the hydroxyl group when lignin-carbohydrate complexes were de-structured by the enzymes. This study expanded the application of CNF produced from unbleached pulp. The theoretical foundation for stabilizing the CNF suspension and the high-speed dehydration of CNF films were explored for the continuous roll to roll production of CNF film. [ABSTRACT FROM AUTHOR]

To study the influence of the content of hemicellulose on the absorbable organic halogen (AOX) formation in chlorine dioxide bleaching, a pH pre-corrected hot water pretreatment was developed. The influence of lignin on AOX formation was eliminated by the control of hot water extraction time, AOX formation was decreased by 33.27% under optimal hot water extraction conditions. The chemical composition of bleaching effluent was analyzed by GC–MS, and the formation of chlorobenzene and chlorophenol was inhibited by removal of hemicellulose, the ring structures of which were degraded into chain macromolecules and small molecules. The hemicellulose structure of raw material and bleached pulp was characterized by ATR-FTIR and NMR. This finding revealed differences in the structures of the bagasse hemicelluloses and the solid residual hemicelluloses. AOX formation was affected by the structure of hemicellulose. A new process combining biorefinery and clean pulp and paper was developed through these experiments. [ABSTRACT FROM AUTHOR]

Xylanase-aided chlorine dioxide bleaching of bagasse pulp was investigated. The pulp was pretreated with xylanase and followed a chlorine dioxide bleaching stage. The ATR-FTIR and XPS were employed to determine the surface chemistry of the control pulp, xylanase treated and chlorine dioxide treated pulps. The hexenuronic acid (HexA) could obviously be reduced after xylanase pretreatment, and the adsorbable organic halides (AOX) were reduced after chlorine dioxide bleaching. Compared to the control pulp, AOX could be reduced by 21.4–26.6% with xylanase treatment. Chlorine dioxide demand could be reduced by 12.5–22% to achieve the same brightness. The ATR-FTIR and XPS results showed that lignin and hemicellulose (mainly HexA) were the main source for AOX formation. Xylanase pretreatment could remove HexA and expose more lignin, which decreased the chlorine dioxide demand and thus reduced formation of AOX. [ABSTRACT FROM AUTHOR]

To reduce the degradation of cellulose and obtain high molecular weight of hemicellulose from the extracts, pH pre-corrected hot water pretreatment was developed by employing sodium hydroxide (3.9 mol/L). The response surface model was established to optimize the extraction process. The species composition and purity of hemicellulose extract was analyzed by High Performance Liquid Chromatography (HPLC). The obtained solid remainder was analyzed by FTIR and SEM. The results showed that the component of xylose in hemicellulose extract was similar with commercial xylan. FTIR and SEM were shown to be able to evaluate solid remainder composition and surface characterization of the bagasse. The biggest balance between solid remainder and dissolved solid was obtained. Not only the yield of dissolved solid was improved, but the structure of solid remainder was also proved, which was beneficial to pulping and papermaking. [ABSTRACT FROM AUTHOR]

Highlights: [•] Reaction between lignin model compound and ClO2 is researched by UV–vis. [•] Reaction mechanism of lignin model compound oxidation by ClO2 is derived. [•] Kinetics for lignin model compound oxidation by ClO2 is propose. [•] Bring new door open for resolving the environmental pollution in ECF bleaching. [ABSTRACT FROM AUTHOR]

Highlights: Typical structures/working mechanisms of gel-based triboelectric nanogenerators and performance advantages of gel materials reviewed. Optimization of hydrogels, organogels, and aerogels for triboelectric nanogenerators in flexible sensing summarized. Applications, challenges, and future development directions of gel-based triboelectric nanogenerators in flexible sensing are discussed. The rapid development of the Internet of Things and artificial intelligence technologies has increased the need for wearable, portable, and self-powered flexible sensing devices. Triboelectric nanogenerators (TENGs) based on gel materials (with excellent conductivity, mechanical tunability, environmental adaptability, and biocompatibility) are considered an advanced approach for developing a new generation of flexible sensors. This review comprehensively summarizes the recent advances in gel-based TENGs for flexible sensors, covering their principles, properties, and applications. Based on the development requirements for flexible sensors, the working mechanism of gel-based TENGs and the characteristic advantages of gels are introduced. Design strategies for the performance optimization of hydrogel-, organogel-, and aerogel-based TENGs are systematically summarized. In addition, the applications of gel-based TENGs in human motion sensing, tactile sensing, health monitoring, environmental monitoring, human–machine interaction, and other related fields are summarized. Finally, the challenges of gel-based TENGs for flexible sensing are discussed, and feasible strategies are proposed to guide future research. [ABSTRACT FROM AUTHOR]

Bubble status monitoring is essential for designing material nanostructures and optimizing industrial processes. However, tracking the fluid dynamics of bubbles is challenging due to their random distribution and irregular dynamic changes. In this study, a tube liquid–solid triboelectric nanogenerator serves as a probe to investigate bubbles at the liquid–solid interface. The study explores the impact of bubble fluid dynamics on liquid–solid contact electrification, examining variables such as flow rates, volumes, and release intervals of bubbles. The study demonstrates that the liquid–solid triboelectric probe can work as a non‐intrusive and self‐powered sensor for monitoring bubble states in chemical fluid control. The sensor exhibits a sensitivity of 13.2 V·cm−3, a signal‐bubble volume correlation coefficient of 0.9964, and a rapid response time of 0.15 s. The sensor, integrated with a wireless module, enables continuous remote detection. This work provides a valuable tool for investigating tri‐phase contact electrification dynamics and presents promising technology for bubble state monitoring. [ABSTRACT FROM AUTHOR]

Non‐contact intelligent sensing technology is a key player in the data acquisition and environmental monitoring framework of the Internet of Everything, laying the groundwork for the realization of highly integrated intelligent network systems. However, environmental factors continue to be a major challenge in the process of real‐time monitoring and feedback of objects, constraining the stability and accuracy of the sensing signals. In this study, a hierarchical spatial assembly strategy is implemented to effectively integrate an intermediate energy storage layer with superhydrophobic surfaces (CA = 162 ± 2.5°), resulting in the development of a moisture‐resistant triboelectric structural materials with stable monitoring and tracking capabilities. The moisture‐resistant self‐powered sensor constructed from this triboelectric structural material operates effectively in extreme humidity conditions (99% RH) with a full‐scale output retention rate of 95.2%, and is capable of accurately sensing human activity from the distance of 3 m. Importantly, the sensor can also effectively detect vehicle states during operation and perform real‐time monitoring of the vehicle's surrounding environment. This study not only overcomes the long‐standing challenges of accuracy and stability in high humidity for sensors but also advances the development of sustainable, interconnected intelligent systems for the Internet of Everything in extreme environmental conditions. [ABSTRACT FROM AUTHOR]

• PFOTES was used to enhanced the tribo-polarity and hydrophobicity of CNF-based TENG. • PFOTES-CNF-based TENG exhibit enhanced triboelectric performance. • The Isc reached 9.3 μA, which is about twice that of a pure CNF-based TENG. • The PFOTES-CNF-based TENG retains 70% of the initial output at 70% ambient humidity. Cellulose is the most abundant natural polymer on earth. Because it is renewable, biodegradable, and biocompatible, it offers distinct advantages as a starting material for bio-based triboelectric nanogenerator (bio-TENG). However, weak polarity, poor hydrophobicity, and insufficient functionalization on the natural cellulose surface severely limit the development of high-performance cellulose-based TENGs. In this work, chemical functionalization is employed to control the surface polarizability and hydrophobicity of cellulose nanofibrils (CNFs). Functional groups on the CNF surface are modified with triethoxy-1H,1H,2H,2H-tridecafluoro-n-octylsilane (PFOTES) in a straightforward and facile process. Fluorine-bearing silane chains are grafted to the surface of CNFs, which increases their triboelectric charge density and improves their hydrophobicity. Experimental results demonstrate that the surface polarity of CNFs is greatly improved after PFOTES modification. The PFOTES-CNF-based TENG exhibits good resistance to humidity and long-term cycle stability, and it retains 70% of the initial output performance at 70% ambient humidity. The short-circuit current of the PFOTES-CNF-based TENG reached 9.3 μA, which is about twice that of CNF-based TENG prior to modification. These results clearly indicate that PFOTES can be used to control CNF surface polarizability and hydrophobicity, advancing the search for durable, high-performance, degradable bio-TENGs. [ABSTRACT FROM AUTHOR]

• A novel CNF/rGO aerogel with supporting column and 2D layered structure was prepared. • CNF/rGO aerogel film with low loading has efficient thermal management performance. • Thermal conductivity of CNF/rGO aerogel with 1 wt.% rGO can reach upto 16.304 W/m K. • The CNF/rGO aerogel film shows potential for emergent energy storage devices. Cellulosic materials are especially suitable for use in flexible electronic products because of their light weight, good tolerance, flexibility, and biodegradability. In this work, cellulose nanofibril/reduced graphene oxide (CNF/rGO) nanocomposites are prepared and the thermal properties of the nanocomposites are analyzed. A supporting column and 2D layered structure porous paper is obtained with CNF/rGO as the heat conduction skeleton, which shows excellent thermal conductivity. The results show that this novel CNF/rGO porous paper has an ultrahigh in-plane thermal conductivity of up to 16.30 W/m K when only 1 wt.% rGO is added in, demonstrating efficient thermal management performance of the CNF-based nanocomposites with low rGO loading. We believe that the development of thermal management techniques using CNFs and rGO for emergent energy storage devices will lead to efficient technologies, further easing our daily lives. [ABSTRACT FROM AUTHOR]

Nanocomposites consisting of cellulose nanofibrils (CNFs) and nano-aluminum nitride (AlN) were prepared using a simple vacuum-assisted filtration process. Bleached sugarcane bagasse pulp was treated with potassium hydroxide and sodium chlorite, and was subsequently ultra-finely ground and homogenized to obtain CNFs. Film nanocomposites were prepared by mixing CNFs with various AlN amounts (0–20 wt.%). X-ray diffraction revealed that the crystal form of CNF-AlN nanocomposites was different to those of pure CNFs and AlN. The mechanical performance and thermal stability of the CNF-AlN nanocomposites were evaluated through mechanical tests and thermogravimetric analysis, respectively. The results showed that the CNF-AlN nanocomposites exhibited excellent mechanical and thermal stability, and represented a green renewable substrate material. This type of nanocomposite could present great potential for replacing traditional polymer substrates, and could provide creative opportunities for designing and fabricating high-performance portable electronics in the near future. [ABSTRACT FROM AUTHOR]

Material designs for wearable sensors are increasingly important due to variable application scenarios and environmental disturbances. The high temperatures pose a significant challenge to the performance of sensing materials. The reasonable anisotropic structure in materials is recognized as a promising approach to address this challenge. Precise control of the orientation of the material remains difficult, owing to the entropy effect. In this work, a tunable anisotropic triboelectric aerogel via an in situ coupled magnetic alignment and protonation reduction strategy is demonstrated. The designed orientation with a fitting degree of 98% can effectively suppress electron thermionic emission, which enables the surface charge density to reach 75 µC m−2 at 300 °C. Such a perfect coordination between self‐powered sensing and thermostability innovates multifunctional wearable sensing design at high temperatures, allowing aramid‐based aerogel to be a candidate for advanced sensing materials for applications in the military and aerospace fields. [ABSTRACT FROM AUTHOR]

The rapid development of wearable electronics has placed higher demands on the design strategies of triboelectric materials. Aerogels have the potential to become advanced triboelectric materials, however, traditional design strategies often require complex processes and additional chemical cross‐linking agents to improve the stability of the gel structure, which limits its practical application. In this work, a scalable and sustainable self‐assembly drive strategy is proposed for the design of bio‐based triboelectric aerogels with multi‐scale winding structures. Interestingly, the autoacceleration effect, which is regarded as “unfavorable” during the autocatalytic polymerization of supramolecules, is rationally exploited to provide the supramolecules within the matrix with an abundance of multiple hydrogen bonds at the same time as their rapid gelation occurs. Thanks to this, the aerogel film exhibits ultra‐high tensile strength (104 MPa) and remains undeformed after resisting an impact of 8000 times its own weight. Highly robust triboelectric aerogel films are used to build wearable self‐powered sensors with ultra‐fast response in complex environments (48 ms), while enabling real‐time interaction between the wearer and the information network. The design idea of “ turning a detriment into an asset ” in this work provides a new idea for the material construction of highly robust wearable sensors. [ABSTRACT FROM AUTHOR]

Sweet maize stems were treated with hot water and potassium hydroxide to fractionate hemicellulosic polymers. The results showed that the water-soluble hemicelluloses were mainly composed of glucose (27.83%), xylose (27.32%), and galactose (16.81%). In comparison, alkali-soluble hemicelluloses fractionated by acidification and a graded ethanol solution (10%, 20%, 35%, 50%, 65%, and 80%) were mainly composed of xylose (69.73 to 88.62%) and arabinose (5.41 to 16.20%). More highly branched hemicelluloses tended to be precipitated in a higher concentration of ethanol solution, as revealed by the decreasing xylose to arabinose ratio from 16.43 to 4.21. Structural characterizations indicated that alkali-soluble hemicelluloses fractionated from sweet maize stems were mainly arabinoxylans. The results provided fundamental information on hemicelluloses composition and structure and their potential utilization in the fields of biofuels, biochemicals, and biomaterials. [ABSTRACT FROM AUTHOR]

Triboelectric probes have rapidly developed as an efficient tool for understanding contact electrification at liquid–solid interfaces. However, the liquid–solid electrification process is susceptible to interference from chemical components in mixed solutions, severely limiting the potential applications of triboelectric probes in various liquid environments. This study for the first time reports a triboelectric probe capable of sucrose solution concentration sensing, finding that the dissolution of sucrose destroys the hydrogen bond network between water molecules and forms sucrose–water hydrogen bonds, which alters the fluid mechanics characteristics of the solution and enhances its conductivity, thereby reducing the droplet size and causing an ion charge shielding effect that significantly affects the electron transfer in liquid–solid contact electrification. Owing to the feedback of the triboelectric probe on the sucrose concentration gradient‐type sensing electrical signals, efficient sensing of sucrose solution was achieved (sensitivity of −0.0038%−1, response time of 90 ms). The triboelectric probe is also used as a wireless smart terminal to enable real‐time detection of sucrose solution. This work contributes to the understanding of the structure–function relationship between micro hydrogen bonding and macro performance, and provides a promising solution for building sustainable intelligent sensors. [ABSTRACT FROM AUTHOR]

The advent of self‐powered wearable electronics will revolutionize the fields of smart healthcare and sports monitoring. This technological advancement necessitates more stringent design requirements for triboelectric materials. The triboelectric aerogels must enhance their mechanical properties to address the issue of structural collapse in real‐world applications. This study fabricates stiff nanocellulosic triboelectric aerogels with multiscale structures induced by the Hofmeister effect. The aggregation and crystallization of polymer molecular chains are enhanced by the Hofmeister effect, while ice crystal growth imparts a porous structure to the aerogel at the micron scale. Therefore, the triboelectric aerogel exhibits exceptional stiffness, boasting a Young's modulus of up to 142.9 MPa and a specific modulus of up to 340.6 kN m kg–1, while remaining undeformed even after supporting 6600 times its weight. Even after withstanding an impact of 343 kPa, highly robust wearable self‐powered sensors fabricated with triboelectric aerogels remain operational. Additionally, the self‐powered sensor is capable of accurately detecting human movements, particularly in abnormal fall postures detection. This study provides considerable research and practical value for promoting material design and broadening application scenarios for self‐powered wearable electronics. [ABSTRACT FROM AUTHOR]

[Display omitted] Triboelectric nanogenerators (TENGs), as a new energy conversion device in self-powered sensing devices, have been used at extreme environmental conditions, which poses great challenges to the structural stability and chemical tolerance of triboelectric materials. However, the low tolerance characteristics of traditional triboelectric materials limit their expansion in emerging applications. Cellulose, with its unique multidimensional structure and, controlled surface chemistry regulation advantages, shows great potential in resisting extreme environmental conditions and is emerging as a new candidate. This review aims to design and fabricate cellulosic triboelectric materials with exceptional tolerance, providing a perspective on the emerging applications of TENGs at extreme environmental conditions. First, the performance advantages and design principles of action of cellulosic triboelectric materials at extreme environmental conditions are described. Second, the importance of physical and chemical regulation strategies is discussed through the multi-scale perspective from macroscopic fiber bundles to microscopic cellulose molecules. It also presents the latest applications of cellulosic triboelectric materials at extreme environmental conditions such as wide temperature, high humidity, high corrosion, and radiation. Finally, the idea of how cellulosic triboelectric materials can further expand the development of TENGs application areas is presented. [ABSTRACT FROM AUTHOR]

The rapid rise of triboelectric nanogenerators (TENGs), which are emerging energy conversion devices in advanced electronics and wearable sensing systems, has elevated the interest in high‐performance and multifunctional triboelectric materials. Among them, cellulosic materials, affording high efficiency, biodegradability, and customizability, are becoming a new front‐runner. The inherently low dielectric constant limits the increase in the surface charge density. However, owing to its unique structure and excellent processability, cellulose shows great potential for dielectric modulation, providing a strong impetus for its advanced applications in the era of Internet of Things and artificial intelligence. This review aims to provide comprehensive insights into the fabrication of dielectric‐enhanced cellulosic triboelectric materials via dielectric modulation. The exceptional advantages and research progress in cellulosic materials are highlighted. The effects of the dielectric constant, polarization, and percolation threshold on the charge density are systematically investigated, providing a theoretical basis for cellulose dielectric modulation. Typical dielectric characterization methods are introduced, and their technical characteristics are analyzed. Furthermore, the performance enhancements of cellulosic triboelectric materials endowed by dielectric modulation, including more efficient energy harvesting, high‐performance wearable electronics, and impedance matching via material strategies, are introduced. Finally, the challenges and future opportunities for cellulose dielectric modulation are summarized. [ABSTRACT FROM AUTHOR]

Highlights: This review systematically discusses the interfacial properties of cellulosic material preparation processes, top-down, bottom-up, and composite processes. The rational design strategies of cellulosic triboelectric materials are summarized in detail, and the effects of different design strategies on the surface charge characteristics and charge density of cellulosic triboelectric materials are discussed. A comprehensive review of the research progress of cellulosic triboelectric nanogenerators in the field of self-powered wearable electronics. With the rapid development of the Internet of Things and flexible electronic technologies, there is a growing demand for wireless, sustainable, multifunctional, and independently operating self-powered wearable devices. Nevertheless, structural flexibility, long operating time, and wearing comfort have become key requirements for the widespread adoption of wearable electronics. Triboelectric nanogenerators as a distributed energy harvesting technology have great potential for application development in wearable sensing. Compared with rigid electronics, cellulosic self-powered wearable electronics have significant advantages in terms of flexibility, breathability, and functionality. In this paper, the research progress of advanced cellulosic triboelectric materials for self-powered wearable electronics is reviewed. The interfacial characteristics of cellulose are introduced from the top-down, bottom-up, and interfacial characteristics of the composite material preparation process. Meanwhile, the modulation strategies of triboelectric properties of cellulosic triboelectric materials are presented. Furthermore, the design strategies of triboelectric materials such as surface functionalization, interfacial structure design, and vacuum-assisted self-assembly are systematically discussed. In particular, cellulosic self-powered wearable electronics in the fields of human energy harvesting, tactile sensing, health monitoring, human–machine interaction, and intelligent fire warning are outlined in detail. Finally, the current challenges and future development directions of cellulosic triboelectric materials for self-powered wearable electronics are discussed. [ABSTRACT FROM AUTHOR]

Lignin nanoparticles (LNPs), as one of green and sustainable biological macromolecules, have attracted great attention owing to their promising potentials in many valorized fields. However, the lignin heterogeneity seriously restricts the controllable preparation of LNPs. Herein, a facile nanogrinding activation combining anhydrous ethanol dissolution process was developed to efficiently homogenize lignin prior to gradient ethanol fractionation. Two lignin fractions were obtained from nanogrinding activation/ethanol dissolution followed by gradient ethanol fractionation: L-fractions and S-fractions. Therefore, monodispersed LNPs with unique concave hollow nanostructure and large particle size, and monodispersed LNPs with solid core nanostructure and small particle size were successfully prepared from L-fractions and S-fractions, respectively, via a GVL/water anti-solvent method. The proposed LNPs formation mechanisms facilitated by nanogrinding activation/ethanol dissolution treatment were demonstrated. This study put forwards a facile and green integrated approach for monodispersed LNPs preparation with controllable morphology and particle size. [Display omitted] • Nanogrinding/ethanol treatment facilitates lignin cleavage and fractionation. • The synergistic effect fractionates lignin into L- and S- fractions. • L-/S-fractions possess unique functional groups and molecular distributions. • Monodispersed LNPs with concave hollow and core nanostructures are prepared. • The proposed mechanisms of LNPs formation are demonstrated. [ABSTRACT FROM AUTHOR]

The properties of materials play a significant role in triboelectric nanogenerators (TENGs). Advanced triboelectric materials for TENGs have attracted tremendous attention because of their superior advantages (e.g., high specific surface area, high porosity, and customizable macrostructure). These advanced materials can be extensively applied in numerous fields, including energy harvester, wearable electronics, filtration, and self‐powered sensors. Hence, designing triboelectric materials as advanced functional materials is important for the development of TENGs. Herein, the structural modification methods based on electrospinning to improve the triboelectric properties and the latest research progress in this kind of TENGs are systematically summarized. Preparation methods and design trends of nanofibers, microspheres, hierarchical structures, and doping nanomaterials are highlighted. The factors influencing the formation and properties of triboelectric materials are considered. Furthermore, the latest progress on the applications of TENGs is systematically elaborated. Finally, the challenges in the development of triboelectric materials are discussed, thereby guiding researchers in the large‐scale application of TENGs. [ABSTRACT FROM AUTHOR]

With the vigorous development of the Internet of Things and artificial intelligence, the active sensing system based on triboelectric nanogenerators plays an excellent performance potential and application value as a pioneering technology for smart manufacturing. Nevertheless, achieving material innovation to strike a good balance between active sensing systems and environmental friendliness remains a difficult task. As the most abundant biopolymer on earth, the sustainability potential and excellent performance of cellulose are of great importance for the development of smart sensing systems. This review intends to provide a new perspective on the sustainability of smart active sensing systems to design and fabricate cellulosic triboelectric materials for self‐powered sensing systems. Herein, the structure and advantageous properties of cellulosic triboelectric materials are briefly described. Furthermore, the structure–property–application relationship of the materials is addressed from the perspective of material design and structure optimization. Next, the latest applications of cellulose triboelectric materials are comprehensively described in smart sensing fields such as environmental monitoring, smart home, smart medical, human–machine interaction, and the Internet of everything. Lastly, the current challenges and future developments of cellulose triboelectric materials for smart sensor systems are presented. [ABSTRACT FROM AUTHOR]

Gas‐sensitive materials are capable of dynamic identification and content monitoring of specific gases in the environment, and their applications in the field of gas sensing are promising. However, weak adsorption properties are the main challenge limiting the application of gas‐sensitive materials. A highly adsorbent gas‐sensitive cellulose nanofibril (CNF)‐based triboelectric material with a layered structure is prepared here and it is applied to self‐powered gas sensing. The layered structure of the triethoxy‐1H,1H,2H,2H‐tridecafluoro‐n‐octylsilane cellulose nanofiber (PFOTES‐CNF)‐based gas‐sensitive material further enhances the adsorption of the material due to electrostatic adsorption in the electrostatic field induced by triboelectricity. It is found that the ammonia‐sensitive material obtained by loading Ti3C2Tx in PFOTES‐CNF has a fast response/recovery (12/14 s), high sensitivity response (Vair/Vgas = 2.1), high selectivity response (37.6%), and low detection limit (10 ppm) for 100 ppm of ammonia gas. In addition, the ammonia‐sensitive CNF‐based triboelectric material can accurately identify NH3 concentration changes in the range of 10–120 ppm and transmit the signal wirelessly to the user interface, facilitating real‐time online monitoring of NH3 in the environment. A novel strategy is provided here for designing and preparing high‐performance gas‐sensitive composites and the analysis of self‐powered gas sensing is guided. [ABSTRACT FROM AUTHOR]

Synthetic polymer materials such as paraformaldehyde and polyamides are widely used in the field of energy engineering. However, they pose a challenge to environmental sustainability because they are derived from petrochemicals that are non‐renewable and difficult to degrade in the natural environment. The development of high‐performance natural alternatives is clearly emerging as a promising mitigation option. Inspired by natural bamboo, this research reports a "three‐step" strategy for the large‐scale production of triboelectric materials with special nanostructures from natural bamboo. Benefiting from the special hierarchical porous structure of the material, Bamboo/polyaniline triboelectric materials can reach short‐circuit current of 2.9 µA and output power of 1.1 W m–2 at a working area of only 1 cm2, which exceeds most wood fiber‐based triboelectric materials. More importantly, it maintains 85% energy harvesting after an extreme environment of high temperature (200 °C), low temperature (−196 °C), combustion environment, and multiple thermal shocks (ΔT = 396 °C). This is unmatched by current synthetic polymer materials. This work provides new research ideas for the construction and application of biomass structural materials under extreme environmental conditions. [ABSTRACT FROM AUTHOR]

Though visualizing perspiration constituents is crucial for physiological evaluation, inadequate material healing and unreliable power supply methods restrict its applications. Herein, a fully flexible self‐powered sweat sensor is fabricated from a cellulose‐based conductive hydrogel to address these issues. The hydrogel electrode is composed of a cellulose nanocomposite polymerized in situ with polyaniline and cross‐linked with polyvinyl alcohol/borax. The cellulose nanocomposites furnish the sweat sensor with tensile and electrical self‐healing efficiencies exceeding 95% within 10 s, a stretchability of 1530%, and conductivity of 0.6 S m−1. The sweat sensor quantitatively analyzes Na+, K+, and Ca2+ contents in perspiration, to sensitivities of 0.039, 0.082, and 0.069 mmol–1, respectively, in real time via triboelectric effect and wirelessly transmits the results to a user interface. This fabricated sweat sensor with high flexibility, stability, and analytical sensitivity and selectivity provides new opportunities for self‐powered health monitoring. [ABSTRACT FROM AUTHOR]

Processing lignin into super-hydrophilic graphite by room-temperature chemical carbonization. [Display omitted] • Room-temperature carbonization has cost-effective and eco-friendly features. • Room-temperature carbonization afforded an 87% graphite yield. • Lignin-derived graphite has super-hydrophilicity. • Graphite-encapsulated liquid metal patterns have superb conductivity of 4.9 × 106 S/m. A cost-effective, and low-energy room-temperature cascade catalytic carbonization strategy is demonstrated for converting lignin into graphite with a high yield of 87 %, a high surface potential of −37 eV and super-hydrophilicity. This super-hydrophilic feature endows the lignin-derived graphite to be dispersed in a variety of polar solvents, which is important for its future applications. Encapsulating of liquid metals with the graphite for electrical circuit patterning on flexible substrates is also advocated. These written patterns show superb conductivity of 4.9 × 106 S/m, offering good performance stability and reliability while being repeatedly stretched, folded, twisted, and bent. This will offer new designs for flexible electronic devices, sensors, and biomedical devices. [ABSTRACT FROM AUTHOR]

[Display omitted] Lithium carboxymethyl cellulose (CMC-Li) is a promising novel water-based binder for lithium-ion batteries. The direct synthesis of CMC-Li was innovatively developed using abundant wood dissolving pulp materials from hardwood (HW) and softwood (SW). The resulting CMC-Li-HW and CMC-Li-SW binders possessed a suitable degree of substitutions and excellent molecular weight distributions with an appropriate quantity of long- and short-chain celluloses, which facilitated the construction of a reinforced concrete-like bonding system. When used as cathode binders in LiFePO 4 batteries, they uniformly coated and dispersed the electrode materials, formed a compact and stable conductive network with high mechanical strength and showed sufficient lithium replenishment. The prepared LiFePO 4 batteries exhibited good mechanical stability, low charge transfer impedance, high initial discharge capacity (∼180 mAh/g), high initial Coulombic efficiency (99 %), excellent cycling performance (<3% loss over 200 cycles) and good rate capability, thereby outperforming CMC-Na and the widely used cathode binder polyvinylidene fluoride. [ABSTRACT FROM AUTHOR]

[Display omitted] • DES improved cellulase activity by mainly rising βG activity with 20–35% increase. • DES improved cellulase stability by compacting the spatial structure. • DES formed a protective layer to prevent unproductive adsorption of lignin on cellulase. • DES significantly increased the saccharification efficiency of corn stover and poplar. The introduction of specific choline chloride (ChCl)- and betaine (Bet)-based deep eutectic solvents (DESs) into the conventional acetic acid–sodium acetate solution led to a significant increase in cellulase activity and stability. In particular, a higher enhancement in β-glucosidase activity was obtained, which plays a key role in improving cellulase function. The DESs prolonged the half-life of cellulase. The addition of 10 % (v/v) ChCl/1,3-propanediol (1:2) and 5 % (v/v) Bet/glycerol (1:2) resulted in the most significant improvement, with the half-life of cellulase reaching three times the initial half-life value. The above both DESs allowed the cellulase to maintain an excellent level of activity over time, even after 72 h. The DESs tightened the structure of the enzyme by changing its secondary structure, which had a stabilizing effect on the overall conformation. The density functional theory calculations of DESs revealed that the DES with a more stable structure more effectively protected the active conformation. The molecular dynamics simulation on β-glucosidase indicated that the hydrogen bond donor end of the DES primarily formed hydrogen bonds with the enzyme, which induced a spatially compact conformation by increasing the α-helix content while reducing the β-sheet content. It also restricted the movement of amino acids, particularly stabilizing the active site, and increased the hydrophilic region, thereby enhancing enzyme activity and stability. In addition, the DES formed a protective layer that prevented the unproductive adsorption of lignin on the enzymes during the hydrolysis of lignocellulosic feedstocks. These multiple improvements provided by DESs significantly increased the enzymatic saccharification efficiency of corn stover and poplar. [ABSTRACT FROM AUTHOR]

Cellulose acetate (CA)-based electrospun nanofiber aerogel (ENA) has drawn extensive attention for wastewater remediation due to its unique separation, inherent porosity and biodegradability. However, the low mechanical strength, poor durability, and limited adsorption ability hinder its further applications. We herein propose using silane-modified ENA, namely T-CA@Si@ZIF-67 (T-ENA), with enhanced resilience, hydrophobicity, durability and hetero-catalysis to remediate a complex wastewater containing oil and drug residues. The robust T-ENA was fabricated by pre-doping tetraethyl orthosilicate (TEOS) and ligand in its spinning precursors, followed by in-situ anchoring of porous ZIF-67 on the electrospun nanofibers (ENFs) via seeding method before freeze-drying and thermal curing (T). Results show that the T-ENA displays enhanced mechanical stability/resilience and hydrophobicity without compromise of its high porosity (>98 %) and low density (10 mg/cm3) due to the silane cross-linking. As a result, the hydrophobic T-ENA shows over 99 % separation efficiency towards different oil-water solutions. Meanwhile, thanks to the enhanced adsorption-catalytic ability and the activation of peroxymonosulfate (PMS) from the porous ZIF-67, fast degradation of carbamazepine (CBZ) residue in the wastewater can be achieved within 20 min. This work might provide a novel strategy for developing CA aerogels to remove organic pollutants. [ABSTRACT FROM AUTHOR]

[Display omitted] Triboelectric properties of materials play an essential role in liquid energy harvesting and emerging application. The triboelectric properties of materials can be controlled by chemical functionalization strategy, which can improve the utilization of liquid energy resources or reduce the hazards of electrostatic effects. Herein, the latest research progress in molecular modification based on chemical functionalization to control triboelectric properties of materials is systematically summarized. By introducing the mechanism of contact electrification between liquid and solid materials and the developmental history of liquid–solid contact electrification, the influence of solid surface charge density, wettability and liquid properties on contact electrification of liquid and solid materials is described. Research progress on chemical functionalization for improving the hydrophobicity of solid materials, surface charge density of solid materials and triboelectric properties of liquid materials is highlighted. The focus then turns to the significance of enhanced liquid–solid contact electrification in energy harvesting, self-powered sensors and metal corrosion protection. Recent advances in chemical functionalization strategies for weakening the triboelectric properties of solid and liquid materials are also highlighted. Finally, an outlook of the potential challenges for developing chemical functionalization strategies in the field of solid surface modification and liquid molecular modification is presented. [ABSTRACT FROM AUTHOR]

• TENG significantly improves membrane fouling in ceramic membrane filtration. • A roller-coupled rolling belt TENG with high stability and high electrical output. • The system effectively adjusts the dust migration pattern and morphology. • The system significantly reduces enterprise production costs. Effectively controlling membrane fouling is critically important for enhancing the lifespan of membrane materials and reducing operational costs. This paper introduces a novel approach to control the fouling of gas–solid separation ceramic membranes using a triboelectric negative air ion (NAI) generator. The triboelectric NAI generator mainly consists of a roller-coupled rolling belt triboelectric nanogenerator (RCB-TENG), a boosting circuit, and a NAI emission head module. The RCB-TENG is used to harness the waste kinetic energy in the circular pipeline, and the boosting circuit converts it into high-voltage electrical energy to drive the NAI generator. This study investigated the effects of membrane fouling control, revealing a significant reduction in membrane pressure drop rate by 51.2 % and a decrease in the rate of flux reduction by 78.1 % upon using a triboelectric NAI generator. The backwashing regeneration of the membrane was notably enhanced. The mechanism of membrane fouling control was investigated and it was found that the main control method was through regulating the charge, morphological evolution, and migration characteristics of moving particles. This strengthens the interception and capture on the membrane surface, weakens the inertial collision and diffusion capture effects within the membrane, thereby controlling membrane fouling. This study provides a new perspective for effectively controlling membrane fouling. [ABSTRACT FROM AUTHOR]

A green and facile synthesis of anisotropic 3D architecture high-performance carbon catalyst has been a hot research topic. Herein, a facile and scalable strategy was developed to fabricate an N, S co-doped microcellular carbon from natural polymers of chitosan (N-source) and lignosulfonate (S-source), with the properties enhanced as a result of pre-cryocrushing of natural polymer-based carbon precursors. The as-prepared 3D architecture carbon is mechanically strong and contains cross-linked hierarchical porous micro-sheets and micro-channels. This N and S co-doped carbon, prepared from pre-cryocrushing of chitosan (60%) and lignosulfonate (40%) precursor (NSC/CC-C/L (60/40)), annealed at 900 °C shows unique structures, with significant defects, rough edges, rich micro/meso-pores, large surface area, N and S doping, and high pyridinic-N and thiophene-S contents. The NSC/CC-C/L (60/40)-900 sample exhibits superior performance with favorable kinetics, methanol resistance, and excellent durability as an ORR catalyst, all of which are much better than a commercial Pt/C and most reported metal-free catalysts. Impressively, the onset potential of the NSC/CC-C/L-900 sample reaches 1.08 V (vs. reversible hydrogen electrode) and the half-wave potential is 0.98 V, which are compared to 1.02 and 0.92 V for Pt/C. Image 1 [ABSTRACT FROM AUTHOR]

In the current work, a novel triterpene saponin, named ursolic acid 3-O-[α-L-rhamnopyranosyl(1"→6')]-β-D-glucopyranosyl-28-O-β-D-glucuronopyranoside (1), together with two known flavonol glycosides, kaemferol 3-O-α-L-rhamnopyranoside (2) and quercetin 3-O-β-D-glucopyranoside (3), was isolated from the stem outer barks of Pinus pumila by repeated column chromatography and vacuum liquid chromatography. The chemical structures of the secondary metabolites 1–3 were characterized by their spectroscopic data and other physico-chemical evidence, as well as by comparison with the literature. The secondary metabolites 2 and 3 were found in this species for the first time. [ABSTRACT FROM AUTHOR]

Herein, a green facile approach to improve the flexibility of unbleached bamboo kraft pulp (UBKP) via an immobilized enzyme technology is proposed. Polydopamine (PDA) acts as versatile modification and coating materials of cellulose nanocrystals (CNC) for assembling versatile bio-carriers (PDA@CNC). Cellulase biomacromolecules are efficiently immobilized on PDA@CNC to form cellulase@PDA@CNC nanocomposites. The relative enzyme activity, temperature/pH tolerance, and storage stability of cellulase were significantly improved after immobilization. The degree of polymerization treated UBKP decreased by 5.42 % (25 U/g pulp) compared to the control sample. The flexibility of treated fibers was 6.61 × 1014/(N·m2), which was 96.93 % higher (25 U/g) compared to the control and 3.88 times higher than that of the blank fibers. Cellulase@PDA@CNC performs excellent accessibility to fiber structure and induces high degree of fibrillation and hydrolysis of UBKP fibers, which contributes high softness of obtained tissue handsheets. The bio-carrier PDA@CNC within paper framework may further enhance tissue tensile strength. This study proposes a practical and environmentally friendly immobilization approach of cellulase@PDA@CNC for improving the hydrolysis efficiency and flexibility of UBKP fibers, which provides the possibility to maintain the strength of tissue paper while improving its softness, thus broadening the high-value application of immobilized enzyme technology in tissue production. [Display omitted] • Cellulose nanocrystals (CNC) were modified with polydopamine for assembling versatile bio-carriers. • Cellulase biomacromolecules were efficiently immobilized on bio-carriers via a facile process. • The immobilized cellulase possessed excellent relative activity and stability compared with the control. • The flexibility of pulp fiber was significantly enhanced by immobilized cellulase. • The prepared tissue sheets performed improved softness and other physical properties. [ABSTRACT FROM AUTHOR]

Herein, a green facile approach to improve the flexibility of unbleached bamboo kraft pulp (UBKP) via an immobilized enzyme technology is proposed. Polydopamine (PDA) acts as versatile modification and coating materials of cellulose nanocrystals (CNC) for assembling versatile bio-carriers (PDA@CNC). Cellulase biomacromolecules are efficiently immobilized on PDA@CNC to form cellulase@PDA@CNC nanocomposites. The relative enzyme activity, temperature/pH tolerance, and storage stability of cellulase were significantly improved after immobilization. The degree of polymerization treated UBKP decreased by 5.42 % (25 U/g pulp) compared to the control sample. The flexibility of treated fibers was 6.61 × 1014/(N·m2), which was 96.93 % higher (25 U/g) compared to the control and 3.88 times higher than that of the blank fibers. Cellulase@PDA@CNC performs excellent accessibility to fiber structure and induces high degree of fibrillation and hydrolysis of UBKP fibers, which contributes high softness of obtained tissue handsheets. The bio-carrier PDA@CNC within paper framework may further enhance tissue tensile strength. This study proposes a practical and environmentally friendly immobilization approach of cellulase@PDA@CNC for improving the hydrolysis efficiency and flexibility of UBKP fibers, which provides the possibility to maintain the strength of tissue paper while improving its softness, thus broadening the high-value application of immobilized enzyme technology in tissue production. [Display omitted] • Cellulose nanocrystals (CNC) were modified with polydopamine for assembling versatile bio-carriers. • Cellulase biomacromolecules were efficiently immobilized on bio-carriers via a facile process. • The immobilized cellulase possessed excellent relative activity and stability compared with the control. • The flexibility of pulp fiber was significantly enhanced by immobilized cellulase. • The prepared tissue sheets performed improved softness and other physical properties. [ABSTRACT FROM AUTHOR]

• Residual lignin as reducing agents and stabilisers to embed Ag into lignocellulose matrix in situ. • Hybridization of coarse and fine fibers to balance pressure drop and filtration efficiency. • The self-charging enhancement boasts impressive submicron particle removal (99.70%). • The filter displayed consistent performance and durability in high humidity conditions of 80% RH. The moisture sensitivity and structural defects found in natural cellulose materials limit their ability to serve as substitutes for petroleum-based masks. This study uses a combination of methods, including retaining lignin, embedding silver particles in situ, and using a mixture of coarse and fine fibers to enhance the wet resistance, antibacterial properties, and triboelectric output of lignocellulosic materials. This approach also aimed to balance pressure drop and filtration efficiency. A triboelectric filter (Ag-LCTEF) using a perforated fluorinated ethylene propylene (FEP) film sandwiched between two sheets of Ag-embedded lignocellulose (Ag-LC) was assembled. The resulting Ag-LCTEF enabled self-powered continuous monitoring of breathing signals, boasting impressive submicron particle removal (99.70 %) and antibacterial efficiency (99.18 %), all while maintaining a relatively low-pressure drop of 76 Pa. Notably, the Ag-LCTEF displayed consistent performance and long-term durability even in high humidity conditions of 80 % RH. These remarkable achievements have spurred the suggestion of integrating respiratory protection, monitoring, and diagnostic functions, showcasing its potential for the next generation of wearable electronics. Moreover, naturally safe and biodegradable lignocellulose serves as an environmentally friendly replacement for petroleum-based materials. [ABSTRACT FROM AUTHOR]

A triboelectric nanogenerator (TENG) can convert energy in the surrounding environment to electricity. Therefore, in recent years, research related to TENGs has significantly increased owing to its simple and low‐cost manufacturing process, high portability, and high efficiency. The principle of the TENG lies in the coupling effect of contact electrification and electrostatic induction. Its output performance is directly proportional to the square of the surface charge density, which is related to friction materials. To increase the output power of a TENG and continuously provide electricity for other electronic equipment, many scholars have conducted detailed studies on the triboelectric properties of materials. Particularly, there has been research interest in the chemical functionalization of TENGs due to their unique advantages, such as high triboelectric charge density, durability, stability, and self‐cleaning properties. This Progress Report highlights the research progress in chemical modification methods for improving the charge density of TENGs, and classifies their modification methods according to their mechanisms. The effects of chemical reaction, surface chemical treatment, and chemical substance doping on the output performance of TENGs are systematically elaborated. Furthermore, the applications of chemically modified TENG in self‐powered sensors and emerging fields, including wearable electronic devices, human‐machine interfaces, and implantable electronic devices, are introduced. Lastly, the challenges faced in the future developments of chemical modification methods are discussed, thereby guiding researchers to the use of chemical modification methods for the improvement of charge density for further exploration. [ABSTRACT FROM AUTHOR]

As a green and sustainable porous material, wood has attracted more and more attention of researchers, especially in the field of energy storage. However, the poor conductivity of wood limits its application. Herein, a kind of non-carbonized lignin-free wood (LFW)@PANI supercapacitor material is fabricated for renewable energy storage application. The resultant hybrid used as electrode material of supercapacitor shows a good comprehensive electrochemical performance: 1) A high cycle stability of ~96% after experiencing 5000 cycles. 2) A high specific capacitance of ~800 F g−1 and 192 F cm−3 3) Good rate performance. 4) A high energy efficiency of more than 80%. 5) High energy densities of 41 Wh kg−1 (57 Wh L−1), meanwhile maintaining high power densities of 43 kW L−1 (68 kW kg−1). Compared with the way of carbonization, non-carbonized treatment not only save energy but also be greener. This work is expected to provide more insights and possibilities for application of renewable wood-based materials. Image 1 • Fabrication of LFW@PANI electrode by vacuum pumping and in situ self-polymerization. • Congenital and acquired pores from wood and PANI enhance energy storage performance. • The hybrid displays superior cycle stability, rate performance and energy efficiency. • Non-carbonization provides a simple way for developing high value wood-based hybrid. [ABSTRACT FROM AUTHOR]

• Phosphotungstic acid improved the levulinic acid production in DESs. • The maximum yield of levulinic acid from glucose was 98.9 %. • The maximum yield of levulinic acid cellulose was 88.6 %. • The kinetics of levulinic acid production from cellulose was investigated. A feasible approach to convert glucose and cellulose to levulinic acid applying phosphotungstic acid as catalyst in deep eutectic solvent was proposed. In our study, phosphotungstic acid was considered to be an effective catalyst for levulinic acid production. A considerable yield of levulinic acid (98.9 %) from glucose was achieved using 30 g/L phosphotungstic acid as catalyst at 468 K for 80 min. The peak levulinic acid yield from cellulose was 88.6 % for 120 min at the present temperature and phosphotungstic acid concentration. The reaction system exhibits efficient performance for the conversion of glucose and cellulose, which was due to the combation of phosphotungstic acid and deep eutectic solvent enhanced the levulinic acid production. Additionally, the kinetic study of levulinic acid formation from cellulose was investigated to supply a further insight on the whole biorefining process. The kinetic model agreed with the experiment data well. The activation energy for levulinic acid formation was 47.2 kJ/mol, which obtained from a modified Arrhenius equation. [ABSTRACT FROM AUTHOR]

Green and facile strategies for fabricating hollow microwave absorption materials without harmful solvent etching have attracted extensive attention but still remain a challenge. Herein, the cubic hollow Co/N/C@MnO 2 composites were prepared through metal–organic frameworks (MOFs) self-templated eco-friendly method with polydopamine (PDA) as carbon source and hierarchical MnO 2 nanosheets were incorporated for improving impedance mismatch caused by excessive permittivity in Co/N/C. Such a uniform distribution of Co particles in the N-doped porous carbon matrix, in association with the hollow structure and hierarchical MnO 2 nanosheets, endow the composites with enhanced electromagnetic (EM) wave absorption. Notably, Co/N/C@MnO 2 sample with a filler loading of 15 wt% shows extraordinary EM wave absorbing performance with the minimum reflection loss (RL) of −58.9 dB and wide absorption bandwidth of 5.5 GHz. Several minimum RL values at a thickness in the range of 1.5–5 mm, are below than −50 dB, outperforming many similar materials reported previously. Besides, the possible microwave absorption mechanism was elaborated in detail. Our work provides an environmentally friendly and facile route for fabricating MOFs self-templated hollow carbon-based microwave absorbers. Metal−organic frameworks self-templated cubic hollow Co/N/C@MnO 2 composites shows extraordinary electromagnetic wave absorbing performance due to synergetic effects of optimal impedance match and excellent EM attenuation ability. Image 1 [ABSTRACT FROM AUTHOR]

Bamboo is one of the fastest growing plants in the world, but their shoot buds develop very slowly. Information about the sugar storage and metabolism during the shoot growth is lacking. In the present study, we determined the activity of sucrose and starch metabolizing enzymes during the developmental period of Fargesia yunnanensis from shoot buds to the young culms that have achieved their full height. The soluble sugars and starch contents were also determined and analyzed in shoot buds and shoots at different developmental stages. The results showed that there were higher sucrose contents in shoot buds than shoots, which coincides with the sweeter taste of shoot buds. As the shoot buds sprouted out of the ground, the starch and sucrose were depleted sharply. Coupled with this, the activity of soluble acid invertase (SAI), cell wall‐bound invertase (CWI), sucrose synthase at cleavage direction (SUSYC) and starch phosphorylase (STP) increased significantly in the rapidly elongating internodes. These enzymes dominated the rapid elongation of internodes. The activities of SAI, CWI, SUSYC and STP and adenosine diphosphate‐glucose pyrophosphorylase were higher as compared to other enzymes in the shoot buds, but were far lower than those in the developing shoots. The slow growth of shoot buds was correlated with the low activity of these enzymes. These results complement our understanding of the physiological differences between shoot buds and elongating shoots and ascertain the physiological mechanism for the rapid growth of bamboo shoots. [ABSTRACT FROM AUTHOR]

Polymer composites based on blends of graphene quantum dots (GQDs) with thermoplastic starch (TPS) were prepared by melt-extrusion combined with hot pressing. The GQDs/TPS films were characterized as potential novel, high-performance, and ecofriendly composites replacing traditional non-biodegradable plastic packaging materials. GQDs stock solutions of different concentrations were incorporated into TPS matrices in order to analyze the solid-state fluorescent properties and conductive properties of GQDs/TPS films. The fluorescent, conductive, morphological, mechanical, and optical properties of the GQDs/TPS films were characterized by ultraviolet–visible spectroscopy, surface resistance measurement, scanning electron microscopy, Fourier-transform infrared (FT-IR) spectroscopy, tensile testing, and X-ray diffraction (XRD). FT-IR studies indicated hydrogen bonding between the oxygen-containing groups on GQDs surfaces and the –OH groups in the TPS. The mechanical testing results showed the optimum GQDs loading of 10.9 wt% in the blend. XRD and TEM studies indicated uniform graphene dispersions in the TPS matrix for ≤10.9 wt% GQDs loading; further increases in loading caused agglomeration. The maximum photoluminescence intensity and conductivity of the materials were obtained at 10.9 wt% GQDs loading. These materials have potential applicability in flexible optoelectronic packaging materials. [ABSTRACT FROM AUTHOR]

• The kinetics of furfural production from Eucalyptus sawdust catalyzed by H-SAPO-34 were well studied. • The maximum yield of furfural of 99.28% was obtained in this study. • H-SAPO-34 possesses efficient catalytic activity for conversion of Eucalyptus sawdust into furfural. • Prediction of furfural yield from the generalized model at 210 °C was present in 3D bars and 2D contour plots. The production of platform chemicals from lignocellulosic biomass is scientifically valuable but technologically challenging. With the aim to establish a green reaction system for the production of furfural from lignocellulosic biomass, in the current work, H-SAPO-34 was investigated for catalysis of the conversion of Eucalyptus sawdust to furfural in γ-valerolactone (GVL). H-SAPO-34 was prepared and characterized by XRD, SEM, FTIR, BET, TGA and ammonia adsorbed FTIR. H-SAPO-34 possesses Brønsted and Lewis acid sites and a large specific surface area. The average pore diameter of H-SAPO-34 was 0.86 nm, which is beneficial for the spread of xylose and furfural and the inhibition of humin production. In this work, a peak furfural yield of 99.28% from Eucalyptus was achieved at 210 °C in 120 min with 30 g/L H-SAPO-34. The Brønsted/Lewis acid bifunctionality and the solvent effect of γ-valerolactone possibly contributed to the high furfural yield from real biomass. The kinetics of the conversion of Eucalyptus sawdust to furfural was also studied, and the activation energy for furfural production was calculated. Additionally, the catalytic activity and stability of the regenerated catalyst were estimated. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Carboxymethyl cellulose sodium (CMC) was used to in-situ synthesize foam HKUST-1. • CMC modulated HKUST-1 crystal into huge cubic shape (5.0 μm) with high surface area. • CMC embedded into foam HKUST-1 with Cu O clusters and formed a unique interface. • At P/Po ∼ 0.0026, foam HKUST-1 bared 5.2 times higher toluene uptake than MIL-101(Cr). • Chitosan modified foam HKUST-1 exhibited highest selectivity for acidic dipeptide. Abstract A green and in-situ metal-organic framework (MOF) shaping strategy was proposed to fabricate cellulose foam HKUST-1 and modify with polysaccharides for convenient adsorption applications. The obtained unique foam HKUST-1 not only maintains HKUST-1 intrinsic thermal stability and high surface area, but also exhibits unique crystal structure and interface for HKUST-1. Moreover, the surface and crystal size of foam HKUST-1s can be easily modulated with natural polysaccharides, and the crystal and novel interfaces awarded them 5.2 times higher adsorption uptake (4.52 mmol/g) for vapor-toluene than MIL-101 (Cr) under low pressure P/Po ≈ 0.0026 and high selectivity (1 0 7) for acidic/basic dipeptides EE/RR. Based on the above results, the novel foamed MOFs can be applied for volatile organic compounds (VOCs) adsorption under ambient condition and improve acidic dipeptides enrichment in liquid phase. It will play a significant role as adsorbent in practical adsorption applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • The simulation results successfully guided the preparation of the insulating paper. • Nano-SiO 2 enhances the interfacial binding and compatibility of composite fiber. • Nano-SiO 2 improved the mechanical and insulating properties of the insulating paper. • Nano-SiO 2 reduced the energy barrier of composite fiber and reduce polarization loss. Following the surge in power loads and continuous improvement in the voltage level, insulating papers' mechanical and electrical properties face new challenges. However, traditional inefficient "tentative" trial and error experiments are formidable to rapidly and efficiently prepare cellulose composite insulating paper because the direct scientific theory or simulation guidance is insufficient. To solve this problem, the nano-silica(nano-SiO 2)/polyimide(PI)/cellulose composite models were designed and their mechanical, and dielectric properties were predicted by molecular dynamics (MD) simulation. The preparation of corresponding nano-SiO 2 /PI/cellulose insulating paper was guided by the MD simulation results and their surface morphology, mechanical properties, and electrical properties were investigated. The experimental results are in good agreement with the MD simulation results and confirmed that P3 insulating paper possesses the best comprehensive performance, and its tensile strength, relative permittivity, dielectric loss, volume resistivity, and breakdown strength are 71.44 MPa, 2.39, 0.2%, 5.16 × 1015 Ω∙m, and 75.8 kV∙mm−1, respectively. This work proves the feasibility and effectiveness of using MD simulation to guide the development of new insulating papers, and compared with the existing traditional preparation methods, this method is expected to be applied to study various new materials in the future and promote the vigorous development of new materials. [ABSTRACT FROM AUTHOR]

Tobacco based cellulose nanofiber (TCNF) is a novel nanocellulose that has recently been used to replace undesirable wood pulp fibers in the preparation of reconstructed tobacco sheets (RTS). However, given the strict requirements for controlling toxic chemical content in tobacco products, there is a global interest in developing a green, efficient, and toxic-chemical free approach to isolate TCNF from tobacco stem as a bioresource. In this study, we propose a creative and environmentally friendly method to efficiently and safely isolate TCNF from tobacco stem pulp, which involves integrated biological pretreatment followed by a facile mechanical defibrillation process. Feruloyl esterase is used to pretreat the stem pulp by disrupting the ether and ester bonds between lignin and polysaccharide carbohydrates within the fiber wall, which effectively facilitates cellulase hydrolysis and swelling of the stem pulp fiber, as well as the following mechanical shearing treatment for TCNF isolation. The results demonstrate that TCNF obtained by the comprehensive feruloyl esterase/cellulase/mechanical process exhibit uniform and well-dispersed nanofiber morphology, higher crystallinity, and stronger mechanical properties than those of the control. The addition of 0.5 % TCNF can replace wood pulp by 18 wt% ~ 25 wt% in the production of RTS samples while maintaining their reasonable strength properties. [Display omitted] • A green, efficient and toxic-chemical free integrated method for TCNF preparation was proposed. • Feruloyl esterase facilitates cellulase hydrolysis efficiency of tobacco stem pulp pretreatment. • The synergistic effects of feruloyl esterase/ cellulase system facilitate TCNF isolation. • TCNF performs desirable particle size, morphology and surface charge properties. • TCNF can improve the mechanical properties of RTS by replacing 7 % wood pulp. [ABSTRACT FROM AUTHOR]