Bacterial cellulose carbon aerogel with ultra-high stress retention for flexible sensor.

In recent years, interest in biomass-derived conductive carbon aerogels for flexible wearable sensor devices has been increasing. This paper presents a novel, streamlined methodology for synthesizing nitrogen-phosphorus co-doped carbon aerogels from bacterial cellulose (BC) that exhibit exceptional mechanical and sensing properties. The strategic incorporation of ammonium and phosphate reduces defects during the carbonization phase.

Reconstructed Wood Carbon Aerogel with Single-Atom Sites for Flexible Zn-Air Batteries.

Single-atom catalysts (SACs) have become vital air cathodes for metal-air batteries, but fabricating monolithic SACs with high catalytic activity and mechanical strength is currently lacking. Herein, an all-natural wood carbon aerogel with single-atom sites is reconstructed via modulating the multi-interactions within lignocellulosic components. Cellulose nanofiber (CNF) constitutes an oriented scaffold via physical interweaving and strong electrostatic repulsion, while lignosulfonate, acting as a multifunctional bioligand, coordinates with metal ions and forms hydrogen bonds with CNF to prevent the agglomeration of adjacent metal atoms.

Constructing Pentagonal Topological Defects in Carbon Aerogels for Flexible Zinc-Air Batteries.

In the context of energy conversion, the design and synthesis of high-performance metal-free carbon electrocatalysts for the oxygen reduction reaction (ORR) is crucial. Herein, a one-step nitrogen doping/extraction strategy is proposed to fabricate 3D nitrogen-doped carbon aerogels (NCA-Cl) with rich pentagonal carbon topological defects. The NCA-Cl electrocatalyst exhibits superb ORR activity, displaying a half-wave potential of 0.

Polydopamine modified carbon fiber to improve the comprehensive properties of carbon paper for proton exchange membrane fuel cell.

In this study, polydopamine (PDA) was used to modify functional groups on the surface of carbon fiber (CF), and the effects of different dopamine hydrochloride (DPH) concentrations on the surface morphology, functional groups, contact angle and dispersion stability of CF were studied. Subsequently, the raw carbon paper (RCP), hot-pressed carbon paper (HPCP) and carbon paper (CP) were prepared successively using the modified CF through wet forming, impregnation/hot-pressing, and carbonization methods. The surface morphology, tensile strength, flexural strength, electrical resistivity, air permeability and pore size distribution were analyzed for these materials.

Controllable and Reversible Assembly of Nanofiber from Natural Macromolecules via Protonation and Deprotonation.

Nanofiber is the critical building block for many biological systems to perform various functions. Artificial assembly of molecules into nanofibers in a controllable and reversible manner will create "smart" functions to mimic those of their natural analogues and fabricate new functional materials, but remains an open challenge especially for nature macromolecules. Herein, the controllable and reversible assembly of nanofiber (CSNF) from natural macromolecules with oppositely charged groups are successfully realized by protonation and deprotonation of charged groups.

Tight Binding and Dual Encapsulation Enabled Stable Thick Silicon/Carbon Anode with Ultrahigh Volumetric Capacity for Lithium Storage.

Silicon (Si) is regarded as one of the most promising anode materials for high-performance lithium-ion batteries (LIBs). However, how to mitigate its poor intrinsic conductivity and the lithiation/delithiation-induced large volume change and thus structural degradation of Si electrodes without compromising their energy density is critical for the practical application of Si in LIBs. Herein, an integration strategy is proposed for preparing a compact micron-sized Si@G/CNF@NC composite with a tight binding and dual-encapsulated architecture that can endow it with superior electrical conductivity and deformation resistance, contributing to excellent cycling stability and good rate performance in thick electrode.

Assembling nanocelluloses into fibrous materials and their emerging applications.

Nanocelluloses, derived from various plants or specific bacteria, represent the renewable and sophisticated nano building blocks for emerging functional materials. Especially, the assembly of nanocelluloses as fibrous materials can mimic the structural organization of their natural counterparts to integrate various functions, thus holding great promise for potential applications in various fields, such as electrical device, fire retardance, sensing, medical antibiosis, and drug release. Due to the advantages of nanocelluloses, a variety of fibrous materials have been fabricated with the assistance of advanced techniques, and their applications have attracted great interest in the past decade.

Mass Production of Sulfur-Tuned Single-Atom Catalysts for Zn-Air Batteries.

Single-atom catalysts (SACs) show great potential for rechargeable Zn-air batteries (ZABs); however, scalable production of SACs from sustainable resources is difficult owing to poor control of the local coordination environment. Herein, lignosulfonate, a by-product of the papermaking industry, is utilized as a multifunctional bioligand for the mass production of SACs with highly active MN S sites (M represents Fe, Cu, and Co) via strong metalnitrogen/sulfur coordination. This effectively adjusts the charge distribution and promotes the catalytic performance, leading to highly durable and excellent performance in oxygen reduction and evolution reactions for ZABs.

Cytomembrane-Inspired MXene Ink with Amphiphilic Surfactant for 3D Printed Microsupercapacitors.

Two-dimensional (2D) material-based hydrogels have been widely utilized as the ink for extrusion-based 3D printing in various electronics. However, the viscosity of the hydrogel ink is not high enough to maintain the self-supported structure without architectural deformation. It is also difficult to tune the microstructure of the printed devices using a low-viscosity hydrogel ink.

Shape-Memory and Anisotropic Carbon Aerogel from Biomass and Graphene Oxide.

Biomass, as the most abundant and sustainable resource on the earth, has been regarded as an ideal carbon source to prepare various carbon materials. However, manufacturing shape-memory carbon aerogels with excellent compressibility and elasticity from biomass remains an open challenge. Herein, a cellulose-derived carbon aerogel with an anisotropic architecture is fabricated with the assistance of graphene oxide (GO) through a directional freeze-drying process and carbonization.

Iron Single Atom Catalyzed Quinoline Synthesis.

The production of high-value chemicals by single-atom catalysis is an attractive proposition for industry owing to its remarkable selectivity. Successful demonstrations to date are mostly based on gas-phase reactions, and reports on liquid-phase catalysis are relatively sparse owing to the insufficient activation of reactants by single-atom catalysts (SACs), as well as, their instability in solution. Here, mechanically strong, hierarchically porous carbon plates are developed for the immobilization of SACs to enhance catalytic activity and stability.

Xylan-Derived Light Conversion Nanocomposite Film.

A new type of sustainable light conversion nanocomposite film was fabricated by using carboxymethyl xylan as matrix and xylan-derived carbon dots (CDs) as both light conversion regents and nano reinforcements. The results demonstrate that CDs can not only significantly enhance the mechanical strength of the nanocomposite film because of chemical reaction between CDs and carboxymethyl xylan, but also impart the film with excellent optical properties. With 1.

An Iron-Decorated Carbon Aerogel for Rechargeable Flow and Flexible Zn-Air Batteries.

Mechanically stable and foldable air cathodes with exceptional oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activities are key components of wearable metal-air batteries. Herein, a directional freeze-casting and annealing approach is reported for the construction of a 3D honeycomb nanostructured, N,P-doped carbon aerogel incorporating in situ grown FeP/Fe O nanoparticles as the cathode in a flexible Zn-air battery (ZAB). The aqueous rechargeable Zn-air batteries assembled with this carbon aerogel exhibit a remarkable specific capacity of 648 mAh g at a current density of 20 mA cm with a good long-term durability, outperforming those assembled with commercial Pt/C+RuO catalyst.

Functional Chitosan-based Materials for Biological Applications.

Background: Bio-based materials, as the plentiful and renewable resources for natural constituents which are essential for biomedical and pharmaceutical applications, have not been exploited adequately yet. Chitosan is a naturally occurring polysaccharide obtained from chitin, which has recently attracted widespread attention owing to its excellent activity. This review shows the methods of extraction and modification of chitosan and provides recent progress of synthesis and use of chitosan-based materials in biological applications.

Cobalt Single-Atom-Intercalated Molybdenum Disulfide for Sulfide Oxidation with Exceptional Chemoselectivity.

The identification of chemoselective oxidation process en route to fine chemicals and specialty chemicals is a long-standing pursuit in chemical synthesis. A vertically structured, cobalt single atom-intercalated molybdenum disulfide catalyst (Co -in-MoS ) is developed for the chemoselective transformation of sulfides to sulfone derivatives. The single-atom encapsulation alters the electron structure of catalyst owing to confinement effect and strong metal-substrate interaction, thus enhancing adsorption of sulfides and chemoselective oxidation at the edge sites of MoS to achieve excellent yields of up to 99% for 34 examples.

Cellulose carbon aerogel/PPy composites for high-performance supercapacitor.

Energy storage and conversion systems have recently attracted great interest in application of various electronic devices. Conductive polymers are promising pseudocapacitive materials for supercapacitors due to their low cost, low environmental impact, high pseudo capacitance, and ease of fabrication. However, the poor cycling stability limits their application.

Lignin Nanosphere-Supported Cuprous Oxide as an Efficient Catalyst for Huisgen [3+2] Cycloadditions under Relatively Mild Conditions.

In this work, low-cost lignin nanospheres were fabricated and further applied as an efficient and sustainable support for preparing cuprous oxide (Cu₂O) "green" catalyst by using electrospraying technology. The unalloyed lignin, a special three-dimensional molecular structure, was successfully processed into uniform nanospheres under an electrospraying condition. The synthesized lignin-supported Cu₂O catalyst had a well-defined nanosphere structure, and Cu₂O nanoparticles with sizes less than 30 nm were supported by exposed layers of lignin nanospheres.

Hierarchically Porous Carbon Plates Derived from Wood as Bifunctional ORR/OER Electrodes.

Porous carbon electrodes have emerged as important cathode materials for metal-air battery systems. However, most approaches for fabricating porous carbon electrodes from biomass are highly energy inefficient as they require the breaking down of the biomass and its subsequent reconstitution into powder-like carbon. Here, enzymes are explored to effectively hydrolyze the partial cellulose in bulk raw wood to form a large number of nanopores, which helps to maximally expose the inner parts of the raw wood to sufficiently dope nitrogen onto the carbon skeletons during the subsequent pyrolysis process.

Tailoring the physicochemical properties of chitosan-derived N-doped carbon by controlling hydrothermal carbonization time for high-performance supercapacitor application.

Although a few methods have been employed to fabricate N-doped porous carbons from various N-containing biomass resources, it is still a big challenge to obtain porous carbons with high supercapacitance performances. Herein, we demonstrate that aN-doped porous carbon with superior supercapacitance can be prepared from chitosan by properly controlling hydrothermal carbonization (HC). The physicochemical and supercapacitance properties of the HC-derived carbon are highly time-dependent and can be readily tailored.

Synthesis and characterization of biofunctional quaternized xylan-Fe2O3 core/shell nanocomposites and modification with polylysine and folic acid.

The aims of this study are to prepare quaternized xylan-FeO (QX-FeO) core/shell nanocomposites and explore their potential application in the biomedical fields. γ-FeO nanoparticles synthesized by a facile solvothermal process are coated with QX via reverse microemulsion method and further modified by polylysine (PLL) and folic acid (FA) to prepare PLL-QX-FeO and FA-QX-FeO nanoparticles. An obvious strong absorption of γ-FeO at 580 cm in the spectra of QX-FeO is observed, the Fe element content of QX-FeO is 30-75 μg/mL and the saturation magnetization of QX-FeO nanoparticles is 1.

Solvothermally Controlled Synthesis of Organic-Inorganic Hybrid Nanosheets as Efficient pH-Universal Hydrogen-Evolution Electrocatalysts.

Electrocatalysts with a high efficiency and durability for the hydrogen evolution reaction (HER) hold tremendous promise for next-generation energy conversion. Among the state-of-art catalysts for HER, organic-inorganic hybrid nanosheets exhibit a great potential with the merits of high activity, good durability, and low cost. Nevertheless, there is no general method for the synthesis of binary metal phosphide hybrid nanosheet HER catalysts with a tunable morphology and composition.