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Photonic materials with a tunable chiral nematic structure that can selectively reflect light dynamically are valuable for applications in smart responsive materials. Here, we prepared potential photonic composites with a chiral nematic structure by forming cellulose nanocrystals (CNCs) and waterborne polyurethane (WPU) composites with different compositions on different substrates by evaporation-induced self-assembly. With increasing WPU content, the reflected wavelength increased from 400 to 680 nm, which was mainly caused by the increase of the chiral nematic pitch. In addition, the mechanical properties were better for higher WPU content. WPU was sensitive to small amounts of moisture in ethanol owing to the swollen WPU after absorbing water will increase the helical pitch. The reversible red shift induced by moisture was approximately 100 nm. When wood was used as the substrate, the CNCs still self-assembled to form chiral nematic structures and the adhesion forces of the composites to the wood substrate were strong. By using MgCl 2 solution as an ink, invisible patterns can be written on the coating, which can be revealed temporarily by ethanol. In addition, the invisible pattern of photonic coating is rewritable. The easily prepared environmentally friendly photonic composite has great potential in sensors, anti-counterfeiting labels and smart decorative coatings., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Circularly polarized light (CPL) is key to asymmetric photochemistry as it could impart the chiral organization information into chemical products. Here, we demonstrate the circular polarization capacity of chiral cellulose nanocrystal (CNC) films to trigger photo-alignment of achiral supramolecular polymers into helical structures. Right-handed transmitted (T-) CPL was generated from self-assembled CNC films, which induced amorphous azobenzene (Azo) supramolecular polymers into chiral structures. The chiral induction effect of T-CPL is enhanced on Azo polymers with longer spacers. The absorptive dissymmetry factor (g abs ) values of liquid-crystal supramolecular polymers can be amplified significantly (over 10 times) after T-CPL irradiation. Moreover, by integrating carbon dots into CNC films, CPL emission with a considerable luminescence dissymmetry factor (g lum ) up to -0.66 was achieved, and it could be used for the photo-alignment of Azo polymers with high chiroptical properties. This work provides new insight for the photo modulation of supramolecular polymers by CPL-active materials., (© 2022 Wiley-VCH GmbH.)

Heavy metal ion contamination, in particular that associated with Pb 2+ , Cd 2+ , and Cu 2+ , poses a considerable threat to aquatic environments and human health. To obtain a highly efficient adsorbent, in this work, a facile hydrothermal method was applied to prepare acrylic acid grafted onto cellulose nanocrystal (AA-g-CNC) hydro/aerogel as an adsorbent for Pb 2+ , Cd 2+ , and Cu 2+ removal. The obtained AA-g-CNC hydrogels withstood up to 0.821 MPa of compression and showed good reciprocating performance when the deformation reached 40%. The as-formed AA-g-CNC aerogels had highly porous honeycomb structure, with many functional groups and a high zeta potential, all of which are essential features for an effective adsorbent. The maximum Pb 2+ , Cd 2+ , and Cu 2+ removal capacities of AA-g-CNC aerogels reached 1026, 898.8, and 872.4 mg/g respectively. Their adsorption followed the Freundlich isotherm model and fitted well with pseudo-second-order kinetic models. The adsorption mechanism mainly attributed to electrostatic chelation between metal ions with sulfonate and carboxylate groups.

Nanocellulose fibers (NCFs) aerogels were prepared from poplar alkaline peroxide mechanical pulp (APMP) using physical ultrasonication method. As raw materials, the unique mechanical effects of APMP cause the fiber folding and loose during the pulping process, which was beneficial to further chemical purification and subsequent treatment for long and entangled NCFs. The obtained NCFs exhibited higher crystallinity (77.8%) compared with that of APMP (72.6%) together with diameters range from 20 to 90 nm and self-assembled to network. The primary thermal degradation of NCFs occurred at 331.5°C. The prepared NCFs network aerogels acted as matrix which can prevent the growth and aggregation of ferromagnetic CoFe2O4 nanoparticles. The ratio of the CoFe2O4 of magnetic composites increased from 34 wt% to 75 wt%, and the magnetic properties were all increased with increasing the reaction concentration of FeSO4/CoCl2 salt., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Rod-shaped nanocrystalline cellulose (NCC) was prepared from microcrystalline cellulose (MCC) using the purely physical method of high-intensity ultrasonication. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction was used for the characterization of the morphology and crystal structure of the material. The thermal properties were investigated using thermogravimetric analysis. The reinforcement capabilities of the obtained NCC were investigated by adding it to poly(vinyl alcohol) (PVA) via the solution casting method. The results revealed that the prepared NCC had a rod-shaped structure, with diameters between 10 and 20 nm and lengths between 50 and 250 nm. X-ray diffraction results indicated that the NCC had the cellulose I crystal structure similar to that of MCC. The crystallinity of the NCC decreased with increasing ultrasonication time. The ultrasonic effect was non-selective, which means it can remove amorphous cellulose and crystalline cellulose. Because of the nanoscale size and large number of free-end chains, the NCC degraded at a slightly lower temperature, which resulted in increased char residue (9.6-16.1%), compared with that of the MCC (6.2%). The storage modulus of the nanocomposite films were significantly improved compared with that of pure PVA films. The modulus of PVA with 8 wt.% NCC was 2.40× larger than that of pure PVA., (Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.)

The highly toxic and flammable nature of CO lead to high handling demand for its use and storage, undoubtedly constricting its further academic exploration for carbonylative reactions in laboratory. Although many CO surrogates have been developed and applied in carbonylative reactions instead of CO gas, exploration of more versatile CO surrogates for diverse carbonylations is still highly desirable. Here we report a cellulose‐based CO surrogate (cellulose‐CO), which prepared from cheap and abundant cellulose through a simple and green process. The very mild and efficient CO release makes this reagent a highly competitive candidate for providing CO in carbonylation. This surrogate is compatible with a wide variety of functional groups in various carbonylative reactions due to the excellent compatibility of cellulose‐CO. Moreover, the cellulose‐CO exhibits excellent chemical stability which can be stored exposed to air for 12 months, making this CO surrogate a robust and general reagent in CO chemistry. [ABSTRACT FROM AUTHOR]

Circularly polarized light (CPL) is key to asymmetric photochemistry as it could impart the chiral organization information into chemical products. Here, we demonstrate the circular polarization capacity of chiral cellulose nanocrystal (CNC) films to trigger photo‐alignment of achiral supramolecular polymers into helical structures. Right‐handed transmitted (T‐) CPL was generated from self‐assembled CNC films, which induced amorphous azobenzene (Azo) supramolecular polymers into chiral structures. The chiral induction effect of T‐CPL is enhanced on Azo polymers with longer spacers. The absorptive dissymmetry factor (gabs) values of liquid‐crystal supramolecular polymers can be amplified significantly (over 10 times) after T‐CPL irradiation. Moreover, by integrating carbon dots into CNC films, CPL emission with a considerable luminescence dissymmetry factor (glum) up to −0.66 was achieved, and it could be used for the photo‐alignment of Azo polymers with high chiroptical properties. This work provides new insight for the photo modulation of supramolecular polymers by CPL‐active materials. [ABSTRACT FROM AUTHOR]

Phosphorus‐doped carbon materials are promising alternatives to noble metal‐based catalysts for the highly selective oxidation of benzyl alcohol to benzaldehyde, but it is challenging to achieve high loadings of high‐activity P dopants in metal‐free catalysts. Here, the preparation of high‐loading and well‐dispersed P atoms confined to the surfaces of cellulose‐derived carbon via a dissolving‐doping strategy is reported. In this method, cellulose is dissolved in phosphoric acid to generate a cellulose‐phosphoric supramolecular collosol, which is then directly carbonized. The as‐prepared carbon possesses a high specific surface area of 1491 cm3 g−1 and a high P content of 8.8 wt%. The P‐doped nanoporous carbon shows a superior catalytic activity and cyclic stability toward benzyl alcohol oxidation, with a high turnover frequency of 3.5 × 10−3 mol g−1 h−1 and a low activation energy of 35.6 kJ mol−1. Experimental results and theoretical calculations demonstrate that the graphitic C3PO species is the leading catalytic active center in this material. This study provides a novel strategy to prepare P dopants in nanoporous carbon materials with excellent catalytic performance. [ABSTRACT FROM AUTHOR]

Separating oil and water remains a serious challenge because various oil/water mixtures are generated in large quantities by industrial processes, unexpected accidents, and daily life. Various systems containing materials with specific structures and wettabilities have been investigated as possible solutions to this issue. As a sustainable biological material, wood and its derivatives have many advantageous properties for practical applications. The present review mainly focuses on recent progress in using wood‐derived systems for sustainable oil/water separation. Various types of materials that can be produced from wood are briefly introduced. Strategies for constructing wood‐derived separation materials based on direct use and integration, modification, and carbonization are then highlighted. Next, the use of wood‐derived systems for separating oil/water layered mixtures and oil/water emulsions by filtration and absorption methods are systematically discussed. The review concludes with a brief summary of some of the remaining challenges to be overcome. [ABSTRACT FROM AUTHOR]

A flexible, transparent, and renewable mesoporous cellulose membrane (mCel-membrane) featuring uniform mesopores of ≈24.7 nm and high porosity of 71.78% is prepared via a facile and scalable solution-phase inversion process. KOH-saturated mCel-membrane as a polymer electrolyte demonstrates a high electrolyte retention of 451.2 wt%, a high ionic conductivity of 0.325 S cm−1, and excellent mechanical flexibility and robustness. A solid-state electric double layer capacitor (EDLC) using activated carbon as electrodes, the KOH-saturated mCel-membrane as a polymer electrolyte exhibits a high capacitance of 110 F g−1 at 1.0 A g−1, and long cycling life of 10 000 cycles with 84.7% capacitance retention. Moreover, a highly integrated planar-type micro-supercapacitor (MSC) can be facilely fabricated by directly depositing the electrode materials on the mCel-membrane-based polymer electrolyte without using complicated devices. The resulting MSC exhibits a high areal capacitance of 153.34 mF cm−2 and volumetric capacitance of 191.66 F cm−3 at 10 mV s−1, representing one of the highest values among all carbon-based MSC devices. These findings suggest that the developed renewable, flexible, mesoporous cellulose membrane holds great promise in the practical applications of flexible, solid-state, portable energy storage devices that are not limited to supercapacitors. [ABSTRACT FROM AUTHOR]

Abstract: Multifunctional bionanocomposite foams with 3D interconnected networks showing advantageous mechanical properties, thermal insulation, underwater oleophobicity, and biocompatibility, were made from a chitosan matrix reinforced with nanofibrillated cellulose (NFC). The density of the NFC–chitosan nanocomposite foams can be controlled by varying the NFC/chitosan weight ratio and solid content of the suspension in the fabrication process. The mechanical properties and thermal stability of the nanocomposite foams were significantly improved by increasing the ratio of NFC, and effective thermal insulating performance was exhibited for temperature extremes at 0 °C and 70 °C. Moreover, the NFC–chitosan nanocomposite foams showed a highly efficient oil/water separation capacity even at a severe temperature of 90 °C. In addition, the nanocomposite foams possessed good biocompatibility toward L929 mouse fibroblasts. Therefore, the bionanocomposite foams are available for a number of applications, including as disposable and high‐performance filtration media for water purification, packaging, and biological scaffolds. [ABSTRACT FROM AUTHOR]

Transparent power sources are required for emerging electronics and energy devices. However, most transparent materials/systems present certain problems: they are often fragile and unsuitable for shaping into fixed three-dimensional structures. Here, we attempted to overcome these challenges by constructing a cellulose-based multilayer film as a single-electrode triboelectric nanogenerator (TENG). The TENG was simply fabricated by the step-by-step deposition of a cellulose triboelectric layer, a silver nanowire electrode layer, and a protective cellulose layer. The tightly packed thin film is transparent, flexible and foldable. Four TENGs were spontaneously assembled into one film, and various spatial configurations were generated by a series of cutting and folding processes. We proved the practicality of a TENG-containing cellulose-based multilayer film by developing a multi-dimensional touch password switch, and expect that it will be widely used in film-based intelligent electronics. [Display omitted] • We propose a strategy to develop transparent and foldable cellulose-based single-electrode triboelectric nanogenerator. • Four TENGs were assembled in one piece of film, and various spatial configurations were fabricated by cutting and folding. • Concealment touching password switch was realized simply by finger touching the film at various spatial positions. [ABSTRACT FROM AUTHOR]

Nanocellulose fibrils (NCFs) were isolated from bleached hard kraft pulp (BHKP) using high-intensity ultrasonication, and their reinforcement capabilities for poly (vinyl alcohol) films were investigated. Scanning electron microscopy (SEM), thermogravimetric analysis (TG), and X-ray diffraction (XRD) were used to characterize the fibrils and films. The results revealed that the prepared NCFs were long filaments with a cellulose I crystal structure. The filaments were 50-150 nm in diameter, and had lengths longer than 500 μm. The crystallinity and thermal stability of the NCFs were increased compared with BHKP because of the removal of hemicellulose. A NCFs content of 4 wt% was found to give the best light transmittance and mechanical properties in the PVA composites. The PVA composites exhibited a visible light transmittance of 75 %, and the tensile strength and Young's modulus were significantly improved, with values 1.86 and 1.63 times larger than that of neat PVA. [ABSTRACT FROM AUTHOR]

Fast water permeable filters with an efficient rejection ratio are desirable for nanoparticle separation and water/air purification. Ultrathin nanoporous filters are effective because of their features, including narrow and tunable pore size distributions capable of handling a high solvent flux. However, it remains challenging to develop antifouling filters that maintain a stable flux with high rejection efficiency over long‐term filtration of nanoparticle solutions. Here, a facile and low‐cost approach is reported to fabricate biocompatible hydrogel filters with interconnected nanofiber network structures through the use of high aspect ratio, wood‐derived nanofibrillated cellulose (NFC). The super‐hydrophilia and high porosity of these materials endow the NFC hydrogel filters (NFC‐HFs) with high solvent permeance. Nanofibrous networks and interconnected nanoporous structures of NFC‐HFs promote efficient rejection and precise size‐selective separation of nanoparticles. Specifically, small and irregular nanopores of NFC‐HFs fail to match the size of relatively large nanoparticles, which ensures a relatively stable flux of the NFC‐HFs over the whole filtration process, even under continuous filtration of highly concentrated nanoparticle solutions. [ABSTRACT FROM AUTHOR]

Embedding luminogens into a well-selected rigid matrix has been a particularly attractive way of preparing long afterglow materials. On this basis, seeking green, low-cost and sustainable materials or strategies, remains challenging but desirable. Prompted by the generation of wood fluorescence, a general strategy for preparing long afterglow materials successfully developed by embedding biomass-derived carbon dots into cellulose fibrils. Internal hydrogen bonding interactions between cellulose fibrils and carbon dots strongly erected a confinement effect for protecting the triplet exciton from quenching, leading to an increase of phosphorescence lifetime by seven orders of magnitude. These properties, which originated from such a green and convenient approach, were able to match most of reported long afterglow examples. Moreover, thanks to the humidity sensitivity of cellulose, the materials can behave a unique humidity-dependent phosphorescence property, showing superior potential application in advanced anti-counterfeiting and encryption. Image 1 [ABSTRACT FROM AUTHOR]

High internal phase emulsion is a novel emulsion type for a range of applications, while its preparation is limited by low stability and the selection of proper emulsifiers. Herein, an edible sunflower oil-in-water high internal phase Pickering emulsion (HIPPE) stabilized by complexation of cellulose nanofibrils (CNF) and nanochitin (NCh) is prepared using a two-step method. The stabilization capacity of the CNF/NCh complexes stems from restricted coalescence, droplet breakage, and coarsening upon HIPPE formation, showing the minimal droplet size at 80 μm. This is the result of a dual stabilization mechanism including: enhanced adsorption of the complexes at the oil-water interfaces by existence of the acetyl groups in the complexes and structuring the aqueous phase to form networking structures within HIPPEs. The CNF/NCh complex suspensions exhibit tolerance to changes in pH (3–5) and salinity (0–500 mM), showing capability of forming and stabilizing HIPPEs with minimal alteration to droplet size and morphology. The complex-stabilized HIPPEs remain stability after at least 2-year storage at ambient condition. Overall, complexation of CNF and NCh greatly extend the conditions on forming highly stable, tuneable HIPPEs, offering potential on engineering applications relevant to clean-label, green foodstuffs. [Display omitted] • Edible high internal phase Pickering emulsions (HIPPEs) were stabilized with the cellulose nanofibril/nanochitin complexes. • Addition of nanochitin facilitates adsorption of cellulose nanofibrils at the water-oil interface. • High stability of HIPPEs was originated from dual stabilization mechanism. • The complexes were tolerable to change in pH and salinity for HIPPE preparation. [ABSTRACT FROM AUTHOR]

In this review, we discuss the application of cellulose nanoparticles as a sustainable and cost-effective source of green stabilizers for formulation of foodstuff. Fibrillar cellulose nanocrystal and nanofibril stabilize Pickering systems because of their ability to adsorb at the oil/water interfaces, forming protective layers. They also form associative structures in the continuous phase, increasing their viscoelastic properties and preventing flocculation. We describe the chemical and structural features of nanocelluloses and discuss the principles that support their utilization as stabilizers, especially in the context of recent prospects in food and health domains, given safety and regulatory advances. In addition, we describe the benefits of combining nanocelluloses with other food ingredients to extend their functional attributes. Particularly, nanocellulose-based Pickering emulsions are used to create edible soft materials with multiple functionalities. This article is expected to stimulate the use of nanocelluloses as functional ingredients to create food products with improved performance and novel properties. [Display omitted] • Plant-based nanocellulosic particles are sustainable and economic natural nanoparticles. • Cellulose nanocrystals and nanofibrils are effective stabilizers in Pickering emulsions. • Novel food emulsions are being created from cellulose nanoparticles and composites. • Nanocellulose-stabilized emulsions provide new or improved functionalities in foods. [ABSTRACT FROM AUTHOR]

[Display omitted] • N-doped sulfonated acid-base bifunctional catalyst was synthesized. • Appropriate acid/base ratio favored 5-HMF production with a yield of 50.04%. • Medium basicity and pyridinic N content affected 5-HMF yield and selectivity. • DFT calculation reveled pyridinic N significantly reduced reaction energy barrier. • Glucose isomerization proceeded by pyridinic N-triggered proton transfer mechanism. Considering the essential role of acidic/basic sites in efficient 5-hydroxymentylfurfural (5-HMF) production from cellulose, the superiority of acid-base bifunctional catalysts was unfolded. However, the lack of in-depth research on catalytic mechanism of active sites, especially the basic sites, greatly hinders its chemical utilization. Herein, N-doped sulfonated bifunctional catalysts were rationally designed. The synthesized NCS-1H catalyst exhibited outstanding activity and recyclability. Favorable 5-HMF yield of 50.0 % with 62.9 % of selectivity was obtained. Spin polarized density function theory (DFT) analysis revealed a pyridinic N-triggered proton-shift mechanism of glucose isomerization. Catalyzed by pyridinic N, the proton of glucose on C2 was shifted to O5, leading to the cleavage of C1-O1 bond. As a result, an enol intermediate was formed and converted to fructose. Compared to pyrrolic N and graphitic N, pyridinic N significantly reduced the reaction energy barrier of rate-determining step to 0.79 eV, i.e., C1-O1 bond cleavage. [ABSTRACT FROM AUTHOR]

In direct conversion process of cellulose to 5-hydroxymethylfurfural (5-HMF), undesirable degradation inevitably occurs in the presence of Brønsted acid. Here, a carbonaceous catalyst was synthesized by grafting phosphotungstic acid to directly depolymerize microcrystalline cellulose (MCC) to 5-HMF. This catalyst exhibits high Lewis acidity (43.10 μmol g⁻1) and low Brønsted acidity (4.15 μmol g⁻1) with pyridine as reference compound. To comprehensively analyze the factors affecting MCC depolymerization, central composite design and response surface methodology techniques, incorporating variables such as reaction time, reaction temperature, catalyst dosage and MCC dosage. The highest yield of 5-HMF, 5.88 %, was obtained after 4.90 h at 171 °C using 45 mg of catalyst and 50 mg of MCC in biphasic system consisting of 1-butyl-3-methylimidazole chloride ([BMIM]Cl) and 2- sec -butylphenol. The catalyst was easily recovered and reused five times without a significant loss of catalytic activity. This work highlights the promise of efficient biomass refining by synergizing catalysts with high Lewis acidity and low Brønsted acidity in the biphasic system. [Display omitted] • Functionalized carbonaceous catalyst with high Lewis acidity was prepared. • Direct depolymerized cellulose to 5-HMF in [BMIM]Cl/2- sec -butylphenol biphasic system. • 5-HMF formation was first established by response surface methodology techniques. • Studied the impact of four factors on 5-HMF formation: reaction time, temperature, catalyst, and MCC dosage. [ABSTRACT FROM AUTHOR]

Owing to the negative impact of water on catalyst activity, and the consequent side reactions, the hydrophobicity and acidity of the catalyst are important factors in the conversion of cellulose to 5-hydroxymethylfurfural in an aqueous solvent. In the present study, we prepared SBA-15 catalysts comprising hydrophobic methoxy groups, phosphotungstic acid as Lewis acid groups, and -SO 3 H Brønsted acid groups. The introduction of methoxy groups increased the contact angle of the catalyst from 57.42 to 87.80° and changed its morphology from stubby short rods to long curved sticks. The maximum 5-hydroxymethylfurfural yield (61.24%) was obtained using 2SBA-15-SO 3 H, which comprised 237.31 μmol·g−1 of the Brønsted acid and 14.44 μmol·g−1 of the Lewis acid and had a contact angle of 75.93°. The low yields of levulinic acid and formic acid (below 10%) confirmed the resistance of such SBA-15 catalysts to water. Furthermore, adequate hydrophobicity facilitated glucose isomerization, whereas the catalyst morphology, which tended to comprise short rods, improved the fructose dehydration rate. Density functional theory analysis of the acidity sites route revealed a 3-DG pathway for 1,4,5,6-tetrahydroxy-hexan-2-one generation with Lewis acid sites, and a free energy of 0.13 eV, paralleled by glucose isomerization to fructose through a 1,2-enediol. [Display omitted] • Introduction of methoxy groups changes water-tolerance and morphology of catalyst. • Adequate hydrophobicity of the SBA-15 catalysts facilitated glucose isomerization. • Short rod morphology of the SBA-15 catalysts improved fructose dehydration rate. • 5-HMF yield was reached as 61.24% and <10% of LA and FA was obtained using 2SBA-15-SO 3 H. • 1,4,5,6-tetrahydroxy-hexanone generated by Lewis acid sites through 3-DG pathway. [ABSTRACT FROM AUTHOR]

Inspired by the tubular structures found in naturally occurring thermal-insulating materials, tubular cellulose aerogels with improved mechanical resistant, thermal-insulating and flame-retardant properties were prepared from kapok fibers via a facile process. In contrast to fragileness of traditional organic-inorganic composites, an optimized sample exhibited an ultra-high compressive strength of 32 MPa. The tubular structure of this material resulted in a 37.4 °C increase in heat preservation compared with that obtained from a pulp aerogel without this morphology. The H 3 PO 4 decomposed from (NH 4) 2 HPO 4 in the formulation crosslinked the outermost cellulose fibers to generate a clay-reinforced dense carbon layer in conjunction with montmorillonite, which restricted the movement of flames and the outflow of volatile compounds. The gaseous voids of internal tubular fibers interrupted the heat transport pathways to inhibit thermal transmission and trapped combustible volatiles to reduce the penetration pressure experienced by the dense carbon layer greatly. The combined effects of the carbon layer and tubular structure effectively limited the transfer of heat, oxygen and volatiles, leading to non-combustion of the optimal sample. This study provided a cost-effective and facile approach to prepare of thermal-insulating, fire-safe and high-strength aerogel showing promising applications in exterior wall insulation and vehicle interior. Inspired by the tubular structures in nature, tubular cellulose aerogels with improved mechanical resistant, thermal-insulating and flame-retardant properties were prepared from kapok fibers via a facile process. [Display omitted] • The bio-inspired tubular cellulose aerogel is simply fabricated from kapok fiber. • The tubular structure of aerogel results in a 37.4 °C increase in heat insulation. • The resultant aerogel self-extinguishes and exhibits excellent flame retardancy. • The resultant aerogel achieves an ultra-high compressive strength of 32 MPa. [ABSTRACT FROM AUTHOR]

[Display omitted] A solar-powered pump (SPP) was prepared by brushing CNT on the aerogel top surface which consisted of cellulose, PVA, and tannic acid. As-prepared SPP showed 48.6% higher uranium adsorption than the one without solar irradiation. The SSP has great potential in the recovery of various metal ions in the water under solar irradiation. As a result, the SPP was successfully used to collect uranium in spiked natural seawater. • A solar-powered pump (SPP) was prepared. • SPP showed 48.6% higher uranium adsorption than the one without solar irradiation. • SPP was successfully used to collect uranium in spiked natural seawater. Uranium is of great importance to the nuclear industry and a practical and economic method for recovering uranium from seawater could help to reduce the use of fossil fuels. Available technology for extracting uranium is, however, limited by recovery speed. Here, we report a solar-powered "pump" for recovery of uranium from seawater, as well as steam generation. This "pump" consists of a cellulose-reinforced tannin-functionalized aerogel coated with carbon nanotubes. Upon solar irradiation, the carbon nanotubes generate a local heating effect that can be used to generate steam, which increases the speed and capacity of uranium adsorption. Our work provides a new strategy for recovery of uranium from seawater and could also be used for recovery of other heavy metal ions from wastewater. [ABSTRACT FROM AUTHOR]

• A compressible anisotropic ternary carbon aerogel (CA) of rGO/CDs/CMF is reported. • CDs build electron-rich regions and promote the formation of N-Q to reduce R ct. • The scattered CDs do not sacrifice density, stability, or SSA of ternary CA. • CA has a specific capacitance of 330 F g-1 and deionization capacity of 32.59 mg g−1. Heteroatom-doped carbon materials have received great attention for applications in electrode materials. However, conventional heteroatom-doping methods sacrifice conductivity, stability, and specific surface area (SSA). Here, the carbon quantum dots (CDs) are used as carriers of N, P, O to form electron-rich regions promoting electron transport without decreasing stability and SSA. The CDs promote the formation of graphitic nitrogen in the composite, which effectively reduces their internal resistance by increasing the dielectric constant. Moreover, the orderly growth of ice crystals generates a unique bridged layer structure under bidirectional freeze-casting in a mixture of GO/CDs/microfibrillated cellulose, which gives the composite super-compressibility. Notably, the optimal sample has a 117% increase in specific capacitance. The CDs also improve wettability and thus reduce the charge transfer resistance giving a large desalination capacity of 32.59 mg g−1 (504 mg L−1 NaCl). This work illustrates the unique role of CDs in improving the electrochemical performance of composites. [ABSTRACT FROM AUTHOR]