Rational Design of Amorphous Carbon-Coated Laminar-Structured Wood for Integrating Repeatable Early Fire Detection and High-Temperature Affordable Flexible Pressure Sensing in One System.

High-temperature affordable flexible polymer-based pressure sensors integrated with repeatable early fire warning service are strongly desired for harsh environmental applications, yet their creation remains challenging. This work proposed an approach for preparing such advanced integrated sensors based on silver nanoparticles and an ammonium polyphosphate (APP)-modified laminar-structured bulk wood sponge (APP/Ag@WS). Such integrated sensors demonstrated excellent fire warning performance, including a short response time (minimum of 0.44 s), a long-lasting alarm time (>750 s), and reliable repeatability. Moreover, it achieved high-temperature affordable flexible pressure sensing that exhibited an almost unimpaired working range of 0-7.5 kPa and a higher sensitivity (in the low-pressure range, maximum to 226.03 kPa-1) after fire. The high stability was attributed to reliable structural elasticity, and the wood-derived amorphous carbon is capable of repeatable fire warnings. Finally, a Ag@APP/WS-based wireless fire alarm system that realized reliable house fire accident detection was demonstrated, showing great promise for smart firefighting application.

Rational Manipulation of Active CNT Encapsulated Fe Doped NiCoP Nanoparticles In Situ Grown in Hierarchically Carbonized Wood for High-Current-Density Water Splitting.

Precise morphology design and electronic structure regulation are critically significant to promote catalytic activity and stability for electrochemical hydrogen production at high current density. Herein, the carbon nanotube (CNT) encapsulated Fe-doped NiCoP nanoparticles is in-situ grown in hierarchical carbonized wood (NCF0.5 P@CNT/CW) for water splitting. Coupling merits of porous carbonized wood (CW) substrate, CNT encapsulating and Fe doping, the NCF0.5 P@CNT/CW features remarkable and durable electrocatalytic activity. The overpotentials of NCF0.5 P@CNT/CW at 50 mA cm-2 mV and 205 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) and features high current density of 800 mA cm-2 within 300 mV for both OER and HER. Moreover, NCF0.5 P@CNT/CW displays outstanding overall water splitting performance (η50 = 1.62 V and η100 = 1.67 V), outperforming Pt/C║RuO2 (η50 = 1.74 V), and can achieve the current density of 700 mA cm-2 at a lower cell voltage of 1.78 V. Overpotential is only 4.0 % decay after 120 h measurement at 50 mA cm-2 . Density functional theory (DFT) calculations reveals Fe doping optimizes the binding energy and Gibbs free energy of intermediates, and regulates d-band center of NCF0.5 P@CNT/CW. Such synergistic strategy of morphology manipulation and electronic structure optimization provides a spark for developing effective and robust bifunctional catalysts.

Strong, Lightweight, and Shape-Memory Bamboo-Derived All-Cellulose Aerogels for Versatile Scaffolds of Sustainable Multifunctional Materials.

Strong, lightweight, and shape-memory cellulose aerogels have great potential in multifunctional applications. However, achieving the integration of these features into a cellulose aerogel without harsh chemical modifications and the addition of mechanical enhancers remains challenging. In this study, a strong, lightweight, and water-stimulated shape-memory all-cellulose aerogel (ACA) is created using a combination strategy of partial dissolution and unidirectional freezing from bamboo. Benefiting from the firm architecture of cellulose microfibers bridging cellulose nanofibers /regenerated cellulose aggregated layers and the bonding of different cellulose crystal components (cellulose Iß and cellulose II), the ACA, with low density (60.74 mg cm-3 ), possesses high compressive modulus (radial section: 1.2 MPa, axial section: 0.96 MPa). Additionally, when stimulated with water, the ACA exhibits excellent shape-memory features, including highly reversible compression-resilience and instantaneous fold-expansion behaviors. As a versatile scaffold, ACA can be integrated with hydroxyapatite, carboxyl carbon nanotubes, and LiCl, respectively, via a simple impregnation method to yield functionalized cellulose composites for applications in thermal insulation, electromagnetic interference shielding, and piezoresistive sensors. This study provides inspiration and a reliable strategy for the elaborately structural design of functional cellulose aerogels endows application prospects in various multifunction opportunities.

Modulation of Electronic Synergy to Enhance the Intrinsic Activity of Fe5Ni4S8 Nanosheets in Restricted Space Carbonized Wood Frameworks for Efficient Oxygen Evolution Reaction.

Modulation of electronic structure and composition is widely recognized as an effective strategy to improve electrocatalyst performance. Herein, using a simple simultaneous carbonization and sulfidation strategy, NiFe double hydroxide-derived Fe5Ni4S8 (FNS) nanosheets immobilized on S-doped carbonized wood (SCW) framework by taking benefit of the orientation-constrained cavity and hierarchical porous structure of wood is proposed. Benefiting from the synergistic relationships between bimetal ions, the spatial confinement offered by the wood cavity, and the enhanced structural effects of the nanosheets array, the FNS/SCW exhibit enhanced intrinsic activity, increased accessibility of catalytically active sites, and convection-facilitated mass transport, resulting in an excellent oxygen evolution reaction (OER) activity and durability. Specifically, it takes a low overpotential of 230 mV at 50 mA cm-2 and potential increase is negligible (3.8%) at 50 mA cm-2 for 80 hours. Density functional theory (DFT) calculations further reveal that the synergistic effect of bimetal can optimize the electronic structure and lower the reaction energy barrier. The FNS/SCW used as the cathode of zinc-air battery shows higher power density and excellent durability relative to commercial RuO2, exhibiting a good application prospect. Overall, this research offers proposals for designing and producing effective OER electrocatalysts using sustainable resources.

Construction of Nanofibrillar Networked Wood Aerogels Derived from Typical Softwood and Hardwood: A Comparative Study on the In Situ Formation Mechanism of Nanofibrillar Networks.

The construction of networks within natural wood (NW) lumens to produce porous wood aerogels (WAs) with fascinating characteristics of being lightweight, flexible, and porous is significant for the high value-added utilization of wood. Nonetheless, how wood species affect the structure and properties of WAs has not been comprehensively investigated. Herein, typical softwood of fir and hardwoods of poplar and balsa are employed to fabricate WAs with abundant nanofibrillar networks using the method of lignin removal and nanofibril's in situ regeneration. Benefiting from the avoidance of xylem ray restriction and the exposure of the cellulose framework, hardwood has a stronger tendency to form nanofibrillar networks compared to softwood. Specifically, a larger and more evenly distributed network structure is displayed in the lumens of balsa WAs (WA-3) with a low density (59 kg m-3), a high porosity (96%), and high compressive properties (strain = 40%; maximum stress = 0.42 MPa; height retention = 100%) because of the unique structure and properties of WA-3. Comparatively, the specific surface area (SSA) exhibits 25-, 27-, and 34-fold increments in the cases of fir WAs (WA-1), poplar WAs (WA-2), and WA-3. The formation of nanofibrillar networks depends on the low-density and thin cell walls of hardwood. This work offers a foundation for investigating the formation mechanisms of nanonetworks and for expanding the potential applications of WAs.

N-Doped Carbon Fibers Derived from Porous Wood Fibers Encapsulated in a Zeolitic Imidazolate Framework as an Electrode Material for Supercapacitors.

Developing highly porous and conductive carbon electrodes is crucial for high-performance electrochemical double-layer capacitors. We provide a method for preparing supercapacitor electrode materials using zeolitic imidazolate framework-8 (ZIF-8)-coated wood fibers. The material has high nitrogen (N)-doping content and a specific surface area of 593.52 m2 g-1. When used as a supercapacitor electrode, the composite exhibits a high specific capacitance of 270.74 F g-1, with an excellent capacitance retention rate of 98.4% after 10,000 cycles. The symmetrical supercapacitors (SSCs) with two carbon fiber electrodes (CWFZ2) showed a high power density of 2272.73 W kg-1 (at an energy density of 2.46 W h kg-1) and an energy density of 4.15 Wh kg-1 (at a power density of 113.64 W kg-1). Moreover, the SSCs maintained 81.21% of the initial capacitance after 10,000 cycles at a current density of 10 A g-1, which proves that the SSCs have good cycle stability. The excellent capacitance performance is primarily attributed to the high conductivity and N source provided by the zeolite imidazole framework. Because of this carbon material's unique structural features and N-doping, our obtained CWFZ2 electrode material could be a candidate for high-performance supercapacitor electrode materials.

Synthesis of Cu-Doped TiO2 on Wood Substrate with Highly Efficient Photocatalytic Performance and Outstanding Recyclability for Formaldehyde Degradation.

Photocatalytic oxidation is considered one of the most effective ways to remove formaldehyde from indoor air. However, the use of powder photocatalysts is limited by their low adsorption capacity and strong aggregation tendency. Hence, there is a need for a composite material with good cycling stability and high degradation efficiency. In the present study, a unique wood-based composite is produced by arranging Cu-TiO2 nanoparticles on porous structured wood. The porous structure of wood can adsorb formaldehyde, and the abundant functional groups on the surface can act as a reaction platform for anchoring the Cu-TiO2 nanoparticles. Cu doping facilitates electron interaction between TiO2 and Cu, promotes the transfer of charge carriers, lowers the electron-hole recombination rate, and improves the photocatalytic degradation efficiency of formaldehyde. The photocatalytic efficiency of the wood-based composites was highest (85.59%) when the n(Cu)/n(Ti) ratio was 7%. After nine cycles, the wood composites still had a high degradation rate, indicating good recyclability. Overall, this wood composite is an eco-friendly and promising material for indoor air filtration.

CoP Nanoparticle Confined in P, N Co-Doped Porous Carbon Anchored on P-Doped Carbonized Wood Fibers with Tailored Electronic Structure for Efficient Urea Electro-Oxidation.

Electronic structure optimization and architecture modulation are widely regarded as rational strategies to enhance the electrocatalysts catalytic performance. Herein, a hybridization of ZIF-67-derived CoP nanoparticles embedded in P, N co-doped carbon matrix (PNC) and anchored on P-doped carbonized wood fibers (PCWF) is constructed using a simple simultaneous phosphorization and carbonization strategy. Benefiting from the optimized surface/interface electronic structures, abundant exposed active sites, and outstanding conductivity, the CoP@PNC/PCWF can drive the urea oxidation reaction (UOR) with greater activity and better stability than most recently reported electrocatalysts, in which a potential as low as 1.32 V (vs reversible hydrogen electrode, RHE) is needed to reach 50 mA cm-2 and shows excellent durability. Furthermore, for overall urea splitting, using the CoP@PNC/PCWF electrocatalyst as the anode and commercial Pt/C supported on nickel foam as the cathode, an ultralow cell voltage of 1.50 V (vs RHE) is expected to achieve the 50 mA cm-2 and operate continuously for more than 50 h at 20 mA cm-2 . The reported strategy may shed light on the use of renewable resources to design and synthesize high-performance non-Ni-based phosphides UOR electrocatalysts for energy-saving H2 production.

Improvement of vincamine production of endophytic fungus through inactivated protoplast fusion.

Improvement of the production of vincamine in endophytic fungus VINI-7 was performed by using the inactivated protoplast fusion method. The preparation conditions of protoplasts were optimized by systematic trials with various parameters, and inactivated protoplast fusion was subsequently performed. The mycelium in logarithmic growth phase was treated with 1500 U/mL lywallzyme, 1500 U/mL lysozyme, 2000 U/mL cellulase, and 1000 U/mL snailase solution for 3 h at 30 °C and had the best conditions, in which the concentration of the protoplast was 3.17 × 107 cells/mL. Protoplasts were inactivated by heat, ultraviolet, microwave, sodium nitrite, and diethyl sulfate, respectively. Subsequently, protoplasts inactivated by different methods were subjected to respective protoplast fusion. The results showed that the yield of vincamine in fusants inactivated by mutagens was generally higher than that of fusants inactivated by heat. The highest yield of vincamine in two fusants (U-U1 and N-N1) was 31.6 and 38.7 mg, which increased to 162.24 and 221.16%, respectively, as compared to the parent strain (12.05 mg). LC-MS/MS analysis showed that U-U1 and N-N1 fusants could produce vincamine. Furthermore, the results of genetic stability experiments indicated that U-U1 and N-N1 were genetically stable.

A Temperature-Controlled, Conductive PANI@CNFs/MEO2 MA/PEGMA Hydrogel for Flexible Temperature Sensors.

Electrically conductive, yet stimuli-responsive hydrogels are highly desirable for many technological applications. However, the discontinuous conductivity of hydrogels during the response process has become a bottleneck that limits their application. To overcome this constraint, a linearly tunable, electrically conductive hydrogel is prepared using in-situ polymerized polyaniline (PANI) on a CNFs/MEO2 MA/PEGMA hydrogel (PANI@CMP hydrogel) substrate. The PANI@CMP hydrogel exhibits temperature-tunable electrical conductivity due to the liner relationship between thermosensitivity and temperature of the CMP hydrogel substrate. Furthermore, the stiffness and elasticity of the resultant hydrogel after PANI introduction is enhanced via physical interactions, and the compression load is improved by 42%. A highly sensitive temperature sensor is therefore fabricated with PANI@CMP hydrogel as the flexible induction element, and this sensor achieves temperature monitoring from 20 to 60 °C. This new temperature-controllable conductive hydrogel has excellent mechanical properties, showing great potential for applications in flexible smart sensors, conductive fillers, and medical devices.

Cellulose Nanofibrils Aerogel Cross-Linked by Poly(vinyl alcohol) and Acrylic Acid for Efficient and Recycled Adsorption with Heavy Metal Ions.

Cellulose nanofibrils (CNFs), disintegrated from natural fibers, are promising alternatives in wastewater purification for the porous structure and numerous hydroxyls. The pristine CNFs aerogel has limited mechanical strength and are vulnerable to collapse when exposed to water. In this work, eco-friendly and recycled CNFs aerogel adsorbents were successfully prepared using cellulose nanofibrils (CNFs), which cross-linked by poly(vinyl alcohol) (PVA) and acrylic acid (AA). The combination of PVA and AA endowed CNFs aerogel strong three-dimensional porous structure and desirable adsorption properties. The heavy metal ions were adsorbed on the CNFs-PVA-AA (CPA) adsorbents efficiently and the maximum adsorption capacities for Cu2+ and Pb2+ approached 30.0 mg/g and 131.5 mg/g, respectively. The CPA adsorbent also showed excellent reusability and their adsorption capacities maintained 89% and 88% for Cu2+ and Pb2+ after 5 repeated uses. The adsorption of these heavy metal ions were confirmed to follow pseudo-second-order kinetic and Langmuir isotherm model. The functions of C ═ O and -OH were the major adsorption sites. Chemical adsorption combined with the porous physical adsorption made the CPA to be excellent adsorbent for the removal of heavy metal ions in wastewater.

Lightweight reinforced wood beams through compression of its surface layers combined with the removal of lignin and hemicellulose.

When wood is used as a stressed component of building materials, the parts most prone to failure are the upper and lower surfaces which can be called the weak structure. In a hydrothermal environment, lignin and hemicellulose in wood readily soften and dissolve, thus leading to their designation as the weak structure. The weak structures results in the wood having a low strength. In this paper, the sandwich beam material can be obtained by two steps from the skin self-reinforcement method, whereby the weak structure of the wood surface was removed by the delignification, and then the wood surface was densified. The authenticity of the sandwich structure is proved by a scanning electron microscope (SEM) and density profile analysis. When the moisture content (MC) is 10 %-12 % and the mass loss ratio is 23.04 %, the optimal resilience of the sandwich beam is only 1 %, the maximum modulus of rupture (MOR) and modulus of elasticity (MOE) are 1.42 and 2.1 times greater than those of natural wood, respectively. This finding shows that our method strengthens the weak structure of natural wood, which has good flexural performance and springback ratio.

Fluorescent cellulose nanofibrils-based hydrogel incorporating MIL-125-NH2 for effective adsorption and detection of iodide ion.

To remove iodine ion (I-) from wastewater, a novel hydrogel, the fluorescent cellulose nanofibrils-based hydrogel (FCNH), was synthesized to enable both detection and adsorption of I-. The FCNH comprised cellulose nanofibrils (CNs), silver nanoclusters (AgNCs), and MIL-125-NH2. It exhibited an excellent adsorption capacity for I-, with a maximum adsorption capacity of 373.7 mg/g, fitting both the Langmuir and pseudo-second-order models. Additionally, FCNH displayed excellent regeneration properties, retaining 88.0 % of its initial adsorption capacity after six adsorption-desorption cycles. Functioning as a fluorescent sensor, the synthesized FCNH enabled the detection of I- through dynamic quenching, with linear ranges of 5 to 200 mg/L and 0.2 to 1.0 µg/L, and a determination limit of 0.11 µg/L. Analysis of the adsorption and detection mechanisms revealed that FCNH's outstanding performance arose from its 3D porous structure comprising CNs, AgNCs, and MIL-125-NH2. Economic analysis indicated that FCNH was inexpensive compared to commercially available activated carbon. Thus, FCNH demonstrated significant potential as an economical and reusable adsorbent for iodine ion removal.

ß-Cyclodextrin/carbon dots-grafted cellulose nanofibrils hydrogel for enhanced adsorption and fluorescence detection of levofloxacin.

In this study, a novel hydrogel, ß-cyclodextrin/carbon dots-grafted cellulose nanofibrils hydrogel (ßCCH), was fabricated for removal and fluorescence determination of levofloxacin (LEV). A comprehensive analysis was performed to characterize its physicochemical properties. Batch adsorption experiments were conducted, revealing that ßCCH reached a maximum adsorption capacity of 1376.9 mg/g, consistent with both Langmuir and pseudo-second-order models, suggesting that the adsorption process of LEV on ßCCH was primarily driven by chemical adsorption. The removal efficiency of ßCCH was 99.2 % under the fixed conditions (pH: 6, initial concentration: 20 mg/L, contact time: 300 min, temperature: 25 °C). The removal efficiency of ßCCH for LEV still achieved 97.3 % after five adsorption-desorption cycles. By using ßCCH as a fluorescent probe for LEV, a fast and sensitive method was established with linear ranges of 1-120 mg/L and 0.2-1.0 µg/L and a limit of detection (LOD) as low as 0.09 µg/L. The viability of ßCCH was estimated based on the economic analysis of the synthesis process and the removal of LEV, demonstrating that ßCCH was more cost-effective than commercial activated carbon. This study provides a novel approach for preparing a promising antibiotic detection and adsorption material with the advantages of stability, and cost-effectiveness.

A Novel Flame-Retardant, Smoke-Suppressing, and Superhydrophobic Transparent Bamboo.

Silica glass, known for its brittleness, weight, and non-biodegradable nature, faces challenges in finding suitable alternatives. Transparent wood, made by infusing polymers into wood, shows promise but is hindered by limited availability of wood in China and fire risks associated with its use. This study explores the potential of utilizing bamboo, which has a shorter growth cycle, as a valuable resource for developing flame-retardant, smoke-suppressing, and superhydrophobic transparent bamboo. A 3-layered flame-retardant barrier, composed of a top silane layer, an intermediate layer of SiO2 formed through hydrolysis-condensation of Na2SiO3 on the surface, and an inner layer of Na2SiO3, has been confirmed to be effective in reducing heat release, slowing flame spread, and inhibiting the release of combustible volatiles, toxic smoke, and CO. Compared to natural bamboo and other congeneric transparent products, the transparent bamboo displays remarkable superiority, with the majority of parameters being notably lower by an entire order of magnitude. It achieves a long ignition time of 116 s, low total heat release (0.7 MJ/m2), low total smoke production (0.063 m2), and low peak CO concentration (0.008 kg/kg). Moreover, when used as a substrate for perovskite solar cells, the transparent bamboo displays the potential to act as a light management layer, leading to a marked efficiency enhancement of 15.29%. The excellent features of transparent bamboo make it an enticing choice for future advancements in flame-retardant glasses and optical devices.

Enhanced sorption and fluorescent detection of bisphenol A by using sodium alginate/cellulose nanofibrils/ZIF-8 composite hydrogel.

To address the issue of bisphenol A (BPA) contamination in wastewater, a novel hydrogel, sodium alginate/cellulose nanofibrils/ZIF-8 composite hydrogel (SCZC), was synthesized for efficient BPA removal. The SCZC exhibited an exceptional adsorption capacity of 1696 mg/g, aligning well with both Langmuir and pseudo-second-order models. Furthermore, it exhibited remarkable regeneration properties, maintaining 89.1 % of its adsorption capacity even after undergoing five adsorption-desorption cycles. The synthesized SCZC also acted as a fluorescent sensor for detecting BPA, employing dynamic quenching and offering linear detection ranges of 10-100 mg/L and 0.2-1.0 µg/L, with a low detection limit of 0.06 µg/L. Analysis of adsorption and detection mechanisms revealed that SCZC's exceptional performance could be attributed to the three-dimensional (3D) porous structure formed by sodium alginate and cellulose nanofibrils. Economic analysis indicated that SCZC, in comparison to commercially activated carbon, was relatively inexpensive. This study introduces a novel approach for designing and preparing a sodium alginate-based hydrogel incorporating metal-organic frameworks, offering simultaneous BPA detection and removal capabilities.

Cayratia albifolia C.L.Li exerts anti-rheumatoid arthritis effect by inhibiting macrophage activation and neutrophil extracellular traps (NETs).

BACKGROUND: Cayratia albifolia C.L.Li (CAC), commonly known as "Jiao-Mei-Gu" in China, has been extensively utilized by the Dong minority for several millennia to effectively alleviate symptoms associated with autoimmune diseases. CAC extract is believed to possess significant anti-inflammatory properties within the context of Dong medicine. However, an in-depth understanding of the specific pharmaceutical effects and underlying mechanisms through which CAC extract acts against rheumatoid arthritis (RA) has yet to be established. METHODS: Twenty-four Sprague-Dawley rats were divided into four groups, with six rats in each group. To induce the collagen-induced arthritis (CIA) model, the rats underwent a process of double immunization with collagen and adjuvant. CAC extract (100 mg/kg) was orally administered to rats. The anti-RA effects were evaluated in CIA rats by arthritis score, hind paw volume and histopathology analysis. Pull-down assay was conducted to identify the potential targets of CAC extract from RAW264.7 macrophage lysates. Moreover, mechanism studies of CAC extract were performed by immunofluorescence assays, real-time PCR and Western blot. RESULTS: CAC extract was found to obviously down-regulate hind paw volume of CIA rats, with diminished inflammation response and damage. 177 targets were identified from CAC extract by MS-based pull-down assay. Bioinformatics analysis found that these targets were mainly enriched in macrophage activation and neutrophils extracellular traps (NETs). Additionally, we reported that CAC extract owned significant anti-inflammatory activity by regulating PI3K-Akt-mTOR signal pathway, and inhibited NETosis in response to PMA. CONCLUSIONS: We clarified that CAC extract significantly attenuated RA by inactivating macrophage and reducing NETosis via a multi-targets regulation.

Cellulose nanofibril/titanate nanofiber modified with CdS quantum dots hydrogel with 3D porous structure: A stable photocatalytic adsorbent for Cr(VI) removal.

A novel cellulose nanofibril/titanate nanofiber modified with CdS quantum dots hydrogel (CTH) was synthesized as an effective, stable, and recyclable photocatalytic adsorbent using cellulose nanofibril (CN), titanate nanofiber (TN), and CdS quantum dots. Within the CTH structure, CN formed an essential framework, creating a three-dimensional (3D) porous structure that enhanced the specific surface area and provided abundant adsorption sites for Cr(VI). Simultaneously, TN modified with CdS quantum dots (TN-CdS) served as a nanoscale Z-type photocatalyst, facilitating the efficient separation of photoinduced electrons and holes, further increasing the photocatalytic efficiency. The morphological, chemical, and optical properties of CTH were thoroughly characterized. The CTH demonstrated the maximum theoretical adsorption capacity of 373.3 ± 14.2 mg/g, which was 3.4 times higher than that of CN hydrogel. Furthermore, the photocatalytic reduction rate constant of the CTH was 0.0586 ± 0.0038 min-1, which was 6.4 times higher than that of TN-CdS. Notably, CTH displayed outstanding stability, maintaining 84.9 % of its initial removal efficiency even after undergoing five consecutive adsorption-desorption cycles. The remarkable performance of CTH in Cr(VI) removal was attributed to its 3D porous structure, comprising CN and TN-CdS. These findings provide novel insights into developing a stable photocatalytic adsorbent for Cr(VI) removal.

Synergistic engineering of P, N-codoped carbon-confined bimetallic cobalt/nickel phosphides with tailored electronic structures for boosting urea electro-oxidation.

Bimetallic phosphides exhibit superior electrocatalytic activities and synergistic effects that make them ideal electrocatalysts for the urea oxidation reaction (UOR). Herein, P, N-codoped carbon-encapsulated cobalt/nickel phosphides derived from NiCo-MOF-74 (NiCoP@PNC) and anchored on P-doped carbonized wood fiber (PCWF) for UOR were prepared through synchronous carbonization and phosphorization. By benefiting from the synergistic effect of structural and electronic modulation, NiCoP@PNC/PCWF exhibits excellent UOR electrocatalytic performance under alkaline conditions, achieving a current density of 50 mA cm-2 with a potential of only 1.34 V (vs reversible hydrogen electrode, RHE) and continuous operation for more than 72 h. In addition, for the overall urea splitting, an electrolyzer using UOR replaced OER, which required only 1.50 V to achieve a current density of 50 mA cm-2 with excellent stability, 230 mV less than that required for the HER||OER system. In-depth theoretical analysis further proves that the strong synergistic effect between Co and Ni optimizes electronic structures, yielding excellent UOR properties. The synergistic strategy of structural and electrical modulation provides broad prospects for the design and synthesis of excellent UOR electrocatalysts for energy-saving hydrogen production by using renewable resources.

Self-assembling behavior of cellulose nanoparticles during freeze-drying: effect of suspension concentration, particle size, crystal structure, and surface charge.

Cellulose nanocrystals and cellulose nanofibers with I and II crystalline allomorphs (designated as CNC I, CNC II, CNF I, and CNF II) were isolated from bleached wood fibers by alkaline pretreatment and acid hydrolysis. The effects of concentration, particle size, surface charge, and crystal structure on the lyophilization-induced self-assembly of cellulose particles in aqueous suspensions were studied. Within the concentration range of 0.5 to 1.0 wt %, cellulose particles self-organized into lamellar structured foam composed of aligned membrane layers with widths between 0.5 and 3 µm. At 0.05 wt %, CNC I, CNF I, CNC II, and CNF II self-assembled into oriented ultrafine fibers with mean diameters of 0.57, 1.02, 1.50, and 1.00 µm, respectively. The size of self-assembled fibers became larger when more hydroxyl groups and fewer sulfates (weaker electrostatic repulsion) were on cellulose surfaces. Possible formation mechanism was inferred from ice growth and interaction between cellulose nanoparticles in liquid-crystalline suspensions.