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Electronic paper displays rely on electrokinetic effects in nonpolar solvents to drive the displacement of colloidal particles within a fluidic cell. While Electrophoresis (EP) is a well-established and frequently employed phenomenon, electro-osmosis (EO), which drives fluid flow along charged solid surfaces, has not been studied as extensively. We hypothesize that by exploiting the interplay between these effects, an enhanced particle transport can be achieved. In this study, we experimentally investigate the combined effects of EP and EO for colloidal particles in non-polar solvents, driven by an electric field. We use astigmatism micro-particle tracking velocimetry (A- μ PTV) to measure the motion of charged particles within model fluidic cells. Using a simple approach that relies on basic fluid flow properties we extract the contributions due to EP and EO, finding that EO contributes significantly to particle transport. The validity of our approach is confirmed by measurements on particles with different magnitudes of charge, and by comparison to numerical simulations. We find that EO flows can play a dominant role in the transport of particles in electrokinetic display devices. This can be exploited to speed up particle transport, potentially yielding displays with significantly faster switching times. Interplay of electrokinetic effects : Driven by the applied electric field, both electro-osmosis (EO, top left), which drives a flow along the surfaces of the fluidic cell, and electrophoresis (EP, top right), which drives a migration of particles relative to the background liquid, occur in our system. A typical example of the resultant particle velocity field (bottom) illustrates the important role of EO on particle transport in the fluidic cell. • Studied electrokinetics of particles in nonpolar solvent using astigmatism micro-PTV. • Both electrophoresis (EP) and electro-osmosis (EO) play important roles. • Combination of EO and EP could be exploited in faster switching e-paper displays. [ABSTRACT FROM AUTHOR]

[Display omitted] SERS measurements for monitoring bactericides in dairy products are highly desired for food safety problems. However, the complicated preparation process of SERS substrates greatly impedes the promotion of SERS. Here, we propose acoustofluidic one-step synthesis of Ag nanoparticles on paper substrates for SERS detection. Our method is economical, fast, simple, and eco-friendly. We adopted laser cutting to cut out appropriate paper shapes, and aldehydes were simultaneously produced at the cutting edge in the pyrolysis of cellulose by laser which were leveraged as the reducing reagent. In the synthesis, only 5 μL of Ag precursor was added to complete the reaction, and no reducing agent was used. Our recently developed acoustofluidic device was employed to intensely mix Ag+ ions and aldehydes and spread the reduced Ag nanoparticles over the substrate. The SERS substrate was fabricated in 1 step and 3 min. The standard R6G solution measurement demonstrated the excellent signal and prominent uniformity of the fabricated SERS substrates. SERS detection of the safe concentration of three bactericides, including tetracycline hydrochloride, thiabendazole, and malachite green, from food samples can be achieved using fabricated substrates. We take the least cost, time, reagents, and steps to fabricate the SERS substrate with satisfying performance. Our work has an extraodinary meaning for the green preparation and large-scale application of SERS. [ABSTRACT FROM AUTHOR]

[Display omitted] The complex spreading dynamics of blood on paper matrix is likely to be quantitatively altered with variations in the fractional occupancy of red blood cells in the whole blood (haematocrit). Here, we presented an apparently surprising observation that a finite volume blood drop undergoes a universal time-dependent spreading on a filter paper strip that is virtually invariant with its hematocrit level within physiologically healthy regime, though distinctively distinguishable from the spreading laws of blood plasma and water. Our hypothesis was ascertained by performing controlled wicking experiments on filter papers of different grades. Spreading of human blood samples of different haematocrit levels ranging between 15% and 51% and the plasma separated from therein were traced by combined high-speed imaging and microscopy. These experiments were complemented with a semi-analytical theory to decipher the key physics of interest. Our results unveiled the exclusive influence of the obstructing cellular aggregates in the randomly distributed hierarchically structured porous pathways and deciphered the role of the networked structures of the various plasma proteins that induced hindered diffusion. The resulting universal signatures of spontaneous dynamic spreading, delving centrally on the fractional reduction in the interlaced porous passages, provide novel design basis for paper-microfluidic kits in medical diagnostics and beyond. [ABSTRACT FROM AUTHOR]

[Display omitted] The quest for efficient hydrogen production highlights the need for cost-effective and high-performance catalysts to enhance the electrochemical water-splitting process. A significant challenge in developing self-supporting catalysts lies in the high cost and complex modification of traditional substrates. In this study, we developed catalysts featuring superaerophobic microstructures engineered on microspherical nickel-coated Chinese rice paper (Ni-RP), chosen for its affordability and exceptional ductility. These catalysts, due to their microspherical morphology and textured surface, exhibited significant superaerophobic properties, substantially reducing bubble adhesion. The nickel oxy-hydroxide (NiO x H y) and phosphorus-doped nickel (PNi) catalysts on Ni-RP demonstrated effective roles in oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), achieving overpotentials of 250 mV at 20 mA cm−2 and 87 mV at −10 mA cm−2 in 1 M KOH, respectively. Moreover, a custom water-splitting cell using PNi/Ni-RP and NiO x H y /Ni-RP electrodes reached an impressive average voltage of 1.55 V at 10 mA cm−2, with stable performance over 100 h in 1 M KOH. Our findings present a cost-effective, sustainable, and easily modifiable substrate that utilizes superaerophobic structures to create efficient and durable catalysts for water splitting. This work serves as a compelling example of designing high-performance self-supporting catalysts for electrocatalytic applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A flexible rechargeable Ag 2 O-Zn battery was in situ constructed on the filter paper. • The tree-root-like interfacial design was achieved between Ag 2 O and filter paper. • The interlocking interface favored high mechanical stability for the Ag 2 O-Zn battery. Flexible zinc–silver oxide (Zn–Ag 2 O) batteries have attracted extensive attention for comfortable wearable electronics owing to their stable output voltage, inherent safety, and environmental benignity. However, they suffer from inferior specific capacity and poor mechanical stability due to the low utilization of Ag 2 O cathodic material and weak interfacial adhesion of active material/substrate. Inspired by the nature of the tree root system, we develop an interface-engineered cathode, in which Ag 2 O nanoparticles are rooted on an Au, Ni co-modified filter paper substrate (CFP) through an electroless plating followed by an in situ electrochemical oxidation. The staggered-stacked Ag 2 O nanoparticles provide abundant electrochemically active sites and convenient ion diffusion paths, and the unique biological tree-root-like structure of the electrode material creates robust interlocking interfaces. A quasi-solid-state Zn–Ag 2 O battery assembled with a tree-root-like Ag 2 O/CFP cathode delivers a high areal specific capacity of 1.08 mAh cm−2 and long-term cycling durability with a capacity retention of 77.3% even after 100 cycles. Moreover, the device presents good mechanical stability under various flexural deformations, including bending, folding, and twisting, and exhibits minimal capacity changes after 1000 bending cycles. These findings suggest that the bio-inspired interface-engineered electrode structure is an efficient approach for developing flexible batteries with excellent electrochemical performance and mechanical properties. [ABSTRACT FROM AUTHOR]

[Display omitted] Lithium metal is deemed a promising anode material for the next-generation batteries with high specific energy. Unfortunately, the growth of Li dendrites and infinite volume change during cycling, caused by the "hostless" feature of metallic Li, have posed a great challenge to the commercialization of Li metal anode. The introduction of appropriate host materials for Li metal is highly desirable. In this work, a N, P dual-doped 3D carbon derived from low-cost quantitative filter paper (NPCQP) is designed and fabricated for direct using as a host for Li metal anode. The resulting NPCQP host achieves a high deposition/stripping Coulombic efficiency of above 97.5 % with a low nucleation overpotential. Moreover, the NPCQP@Li symmetric cells enable an excellent long-term cycling performance (1000 h) with an ultralow voltage hysteresis (12 mV) and stable interface behavior. When paired with the commercial LiFePO 4 cathode, the full cell with NPCQP@Li anode displays impressive long-term cyclic stability and rate capability, outperforming the counter cell with bare Li anode. This contribution sheds light on the rational design of viable host for practical lithium metal anodes. [ABSTRACT FROM AUTHOR]

A bilayer photothermal paper-based 3D cone flowing evaporator with high solar light absorption, low water evaporation enthalpy and excellent salt-rejecting performance is fabricated using multilayered MXene, ultralong hydroxyapatite nanowires, and hydrophilic polymers. The 3D cone flowing evaporator cooperates with a siphon effect-driven unidirectional fluid transportation unit to guide concentrated saline flows out from the evaporating surface, leading to high water evaporation rate and salt-rejecting stable seawater desalination performance. [Display omitted] • A bilayer photothermal paper-based cone flowing water evaporator is reported. • The evaporator exhibits excellent properties for solar seawater desalination. • The evaporator exhibits much higher water evaporation rate than most reported values. • The evaporator can effectively prevent salt accumulation on the evaporating surface. Solar energy-driven water evaporation technology is a promising, low-cost and sustainable approach to alleviate the global clean water shortage, but usually suffers from low water evaporation rate and severe salt deposition on the water evaporation surface. In this work, a hydrophilic bilayer photothermal paper-based three-dimensional (3D) cone flowing evaporator was designed and prepared for stable high-performance seawater desalination with excellent salt-rejecting ability. The as-prepared bilayer photothermal paper consisted of MXene (Ti 3 C 2 T x) and HAA (ultralong hydroxyapatite nanowires, poly(acrylic acid), and poly(acrylic acid-2-hydroxyethyl ester)). The accordion-like multilayered MXene acted as the efficient solar light absorber, and ultralong hydroxyapatite (HAP) nanowires served as the thermally insulating and supporting skeleton with a porous networked structure. A siphon effect-driven unidirectional fluid transportation unit in the 3D cone flowing evaporator could guide the concentrated saline flowing away from the evaporating surface to prevent salt deposition on the evaporation surface, avoiding severe deterioration of the performance in solar water evaporation. Furthermore, combining high solar light absorption and high photothermal conversion efficiencies, low water evaporation enthalpy (1838 ± 11 J g−1), and additional energy taken from the ambient environment, the as-prepared cone flowing evaporator exhibited a high water evaporation rate of 3.22 ± 0.20 kg m−2 h−1 for real seawater under one sun illumination (1 kW m−2), which was significantly higher than many values reported in the literature. This study provides an effective approach for designing high-performance solar energy-driven water evaporators for sustainable seawater desalination and wastewater purification. [ABSTRACT FROM AUTHOR]

[Display omitted] Energy consumption from air cooling systems in summer, water scarcity in hot regions, and the functional reusability of waste paper are emerging environmental problems. Finding solutions to these problems simultaneously remains a significant challenge. Herein, a superhydrophobic passive cooling Cellulose-CaCO 3 film with hierarchical nano-sheets was fabricated to realize daytime radiative cooling with a temperature drop of 15–20 °C in summer and water harvesting with harvesting efficiency of 387 mg cm−2h−1 bd utilization of recycled waste paper. The superhydrophobic Cellulose-CaCO 3 film demonstrates its self-cleaning properties against inorganic and organic pollutants. Furthermore, the superhydrophobicity of the film was maintained after base/acid corrosions, dynamic water flushing, and thermal treatment at 100 °C for 7 h, exhibiting good durability of the superhydrophobicity. Moreover, the superhydrophobic Cellulose-CaCO 3 film is nonflammable after exposure to fire combustion for 1 min. In addition to waste paper, waste maize straws, and pasteboards were also collected to produce superhydrophobic passive cooling films. Results indicate that the above three cellulose-based raw materials can be well used to prepare durable superhydrophobic passive cooling materials. Environmental toxicology assessments confirm the safety of the material. This study not only provides a protocol for preparing superhydrophobic materials; but also demonstrates their potential for passive cooling and water harvesting. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bilayered V 2 O 5 nH 2 O xerogel constructed 2D nanopapers were synthesized. • The V 2 O 5 nH 2 O Xerogel combines oxygen defect engineering. • Oxygen defect improves Zn2+/Mg2+ insertion/extraction kinetics. Aqueous zinc ion batteries (AZIBs) and aqueous magnesium ion batteries (AMIBs) offer powerful alternatives for large-scale energy storage because of their high safety and low cost. Consequently, the design of high-performance cathode materials is essential. In this paper, we present a simple strategy that combines oxygen defect (O d) engineering with a 2D-on-2D homogeneous nanopape-like bilayer V 2 O 5 nH 2 O xerogel (BL-HVO d NPS). This strategy employs O d to improve Zn2+/Mg2+insertion/extraction kinetics and reduce irreversible processes for high-performance AZIBs/AMIBs. And interlayer water molecules serve as an effective spacer to stabilize the expanded interlayer gap in BL-HVO d NPS, thereby providing extended diffusion channels for Zn2+/Mg2+ during insertion/extraction. The interlayer water molecules help shield the electrostatic interaction between Zn2+/Mg2+ and BL-HVO d NPS lattice, which improves diffusion kinetics during repeated. In addition, electrochemical characterization results indicate that the BL-HVO d NPS can effectively the surface adsorption and internal diffusion of Zn2+/Mg2+. More importantly, the successfully prepared unique 2D-on-2D homogenous nanopaper structure enhances electrolyte/electrode contact and reduces the migration/diffusion path of electrons/Zn2+ and Mg2+, thus greatly improving rate performance. As a result, the BL-HVO d NPS as AZIBs/AMIBs electrodes offer better reversible capacity of 361.8 and 162.8 mA h g−1 (at 0.2 A g−1), while displaying impressively long cycle lifes. This method provides a way to prepare advanced xerogel cathode materials for AZIBs and AMIBs. [ABSTRACT FROM AUTHOR]

The MXene-modified papers with high-uniform loading of polypyrrole and excellent conductivity have been fabricated via a multiple self-assembly and in-situ polymerization strategy, which achieves boosting areal capacitance. [Display omitted] • Multiple self-assembly and in-situ polymerization strategy is proposed tofabricate paper-based supercapacitors. • Alternate adsorption of MXene and polypyrrole on paper yields an ultra-high polypyrrole loading of 10.0 mg/cm2. • The paper-based supercapacitor shows a boosting areal capacitance of 2316 mF/cm2. Despite the intriguing features of freestanding flexible electronic devices, such as their binder-free nature and cost-effectiveness, the limited loading capacity of active material poses a challenge to achieving practical high-performance flexible electrodes. We propose a novel approach that integrates multiple self-assembly and in-situ polymerization techniques to fabricate a high-loading paper-based flexible electrode (MXene/Polypyrrole/Paper) with exceptional areal capacitance. The approach enables polypyrrole to form a porous conductive network structure on the surface of paper fiber through MXene grafting via hydrogen bonding and electrostatic interaction, resulting in an exceptionally high polypyrrole loading of 10.0 mg/cm2 and a conductivity of 2.03 S/cm. Moreover, MXene-modified polypyrrole paper exhibits a more homogeneous pore size distribution ranging from 5 to 50 μm and an increased specific surface area of 3.11 m2/g. Additionally, we have optimized in-situ polymerization cycles for paper-based supercapacitors, resulting in a remarkable areal capacitance of 2316 mF/cm2 (at 2 mA/cm2). The capacitance retention rate and conductivity rate maintain over 90 % after undergoing 100 bends.The maximum energy density and cycling stability are characterized to be 83.6 μWh/cm2 and up to 96 % retention after 10,000 cycles. These results significantly outperform those previously reported for paper-based counterparts. Overall, our work presents a facile and versatile strategy for assembling high-loading, paper-based flexible supercapacitors network architecture that can be employed in developing large-scale energy storage devices. [ABSTRACT FROM AUTHOR]

[Display omitted] Solar interfacial evaporation is one of the most efficient and environmentally-friendly clean freshwater production technologies. Plasma metal nanoparticles are excellent optical absorption materials, but their high cost and inherent resonance narrow bandwidth absorption limit their application. In this work, commercial cellulose papers are used as substrates to synthesize Ag-Ni/cellulose paper by the seed-mediated method. The Ag-Ni/cellulose paper exhibits high light absorption at the full wavelength (200–2500 nm) resulting from the synergistic effect of localized surface plasmon resonance (LSPR) of Ag NPs and the interband transitions (IBTs) of Ni. Under one-sun irradiation (1 kW m−2), the energy utilization efficiency of Ag-Ni/cellulose paper is as high as 93.8%, and the water evaporation rate is 1.87 kg m−2 h−1. Diffusion inhibition experiment results show that the Ag-Ni/cellulose paper exhibits excellent antibacterial performance, and the antibacterial performance is highly related with Ag NPs content. These provide new opportunities for commercial production of competitive cost, green, and portable solar evaporators for different application sceneries. [ABSTRACT FROM AUTHOR]

[Display omitted] • Paper mill sludge-based calcium-containing biochar was cleanly prepared. • The maximum phosphorus adsorption capacity of an as-prepared biochar could be up to 68.49 mg·g−1. • Phosphorus was immobilized onto the as-prepared biochar in the forms of CaHPO 4 and Ca 5 (PO 4) 3 (OH). With the increased awareness of reusing solid wastes for higher sustainability and the concern of water pollution associated with phosphorus over-emission, there are strong interests in developing solid waste based adsorbents for purifying phosphorus-containing wastewater. As a rich calcium resource, paper mill sludge (i.e., a major solid waste from pulping industry) can be used as phosphorus removal adsorbent after calcination. Thus, in this work, a simple and clean thermally treating route has been proposed for preparing calcium-containing biochar from paper mill sludge. The effect of the physicochemical properties of paper mill sludge and its carbonization condition on phosphorus adsorption has been analyzed. Moreover, the influence of some key adsorption parameters, e.g., biochar dosage, initial pH of solution, co-existing anions, initial phosphorus concentration and contact time has also been investigated. The results showed that the phosphorus adsorption data could be fitted well with pseudo-second-order kinetic and Langmuir isothermal models. The calculated maximum adsorption capacity of the as-prepared optimal calcium-containing biochar could reach to 68.49 mg·g−1 at 25 °C. Combined with the characterization results, it can be reasonably inferred that the adsorption process was chemisorption-dominated. Lastly, the application of this spent adsorbent in agriculture field has also been discussed. In brief, this work provided a feasible strategy for converting paper mill solid waste to an environmental functional material (i.e., calcium-rich biochar) for remediation of eutrophic water. [ABSTRACT FROM AUTHOR]

• Filter paper was selected as the template for synthesis of 1D NiO/NiCo 2 O 4 composite. • Ultra simple synthetic procedures of only metal salts adsorption and calcination was referred. • The effective bandwidth is up to 6.08 GHz at thin thickness of 1.88 mm. Filter paper, as a widely used and low-cost lab consumable, can serve as template for the synthesis of one-dimensional (1D) materials since it is composed of 1D cellulosic fiber. In this work, 1D NiO/NiCo 2 O 4 composite was simply fabricated by adsorption of Ni and Co acetate on the filter paper and subsequent calcination process. The precursors were obtained without further treatment to filter paper or chemical reaction between metal salts. Calcination process leads to the removal of template and formation of binary NiO/NiCo 2 O 4 composite. Electromagnetic (EM) wave absorption performance of NiO/NiCo 2 O 4 composite could be tuned by adjusting the calcination temperatures and dosage of metal salts. For the optimized absorber (calcination temperature of 600 °C and dosage of Ni and Co acetate with 2 mmol and 4 mmol), a wide absorption bandwidth of 6.08 GHz could be achieved with thickness of 1.88 mm and minimum reflection loss value was up to −57.4 dB by changing the thickness. The facile synthetic route may also inspire the preparation of other high-performance one-dimensional EM wave absorbing materials. [ABSTRACT FROM AUTHOR]

A new kind of nanocomposite filter paper consisting of ultralong hydroxyapatite nanowires, cellulose fibers and double metal oxide nanosheets has been developed for high-performance dye separation. Simultaneous enhancement in water flux and removal efficiency during the filtration process remains a big challenge for separation membranes. The porous structure of the filter paper can provide many channels for water transportation, but the separation performance is generally poor. The purpose of this study is to develop a new kind of filter paper consisting of ultralong hydroxyapatite (HAP) nanowires, cellulose fibers (CFs) and double metal oxide (LDO) nanosheets, and to achieve the simultaneous enhancement of both water flux and removal efficiency for high-performance dye separation. In this work, a novel kind of LDO/HAP/CF nanocomposite filter paper consisting of ultralong HAP nanowires and CFs and LDO nanosheets has been developed for rapid water filtration and highly efficient dye adsorption. Positively charged LDO nanosheets can adsorb on the surface of negatively charged ultralong HAP nanowires and embed in the porous networked structure of the LDO/HAP/CF nanocomposite filter paper, which can provide a porous structure for rapid water transportation and can adjust the pore size of the nanocomposite filter paper. As a result, the pure water flux of the LDO/HAP/CF nanocomposite filter paper can be adjusted. The optimized pure water flux of the LDO/HAP/CF nanocomposite filter paper can reach 783.6 L m−2 h−1 bar−1, which is 1.51 times that of the HAP/CF filter paper without LDO nanosheets (518.6 L m−2 h−1 bar−1). More importantly, the adsorption capacity of LDO nanosheets is high for dye molecules, the rejection percentage of Congo red (CR) by the as-prepared HAP/CF filter paper is only 59.8%, and its water flux is 534.7 L m−2 h−1 bar−1. The optimized rejection percentage and water flux of the LDO/HAP/CF nanocomposite filter paper for CR are significantly enhanced (98.3% and 736.8 L m−2 h−1 bar−1, respectively) compared to those of the HAP/CF filter paper. The size of LDO nanosheets has a significant effect on the water flux and dye rejection percentage of the LDO/HAP/CF nanocomposite filter paper. The as-prepared LDO/HAP/CF nanocomposite filter paper is promising for the applications in highly efficient purification of wastewater containing dye molecules. [ABSTRACT FROM AUTHOR]

[Display omitted] An abundance of early warning graphene-based nano-materials and sensors have been developed to avoid and prevent the critical fire risk of combustible materials. However, there are still some limitations that should be addressed, such as the black color, high-cost and single fire warning response of graphene-based fire warning materials. Herein, we report an unexpected montmorillonite (MMT)-based intelligent fire warning materials that have excellent fire cyclic warning performance and reliable flame retardancy. Combining phenyltriethoxysilane (PTES) molecules, poly(p-phenylene benzobisoxazole) nanofiber (PBONF), and layers of MMT to form a silane crosslinked 3D nanonetwork system, the homologous PTES decorated MMT-PBONF nanocomposites are designed and fabricated via a sol–gel process and low temperature self-assembly method. The optimized nanocomposite paper shows good mechanical flexibility (good recovery after kneading or bending process), high tensile strength of ∼81 MPa and good water resistance. Furthermore, the nanocomposite paper exhibits high-temperature flame resistance (almost unchanged structure and size after 120 s combustion), sensitive flame alarm response (∼0.3 s response once exposure onto a flame), cyclic fire warning performance (>40 cycles), and adaptability to complex fire situations (several fire attack and evacuation scenarios), showing promising applications for monitoring the critical fire risk of combustible materials. Therefore, this work paves a rational way for design and fabrication of MMT-based smart fire warning materials that combine excellent flame shielding and sensitive fire alarm functions. [ABSTRACT FROM AUTHOR]

Novel multifunctional hard core/soft shell colloidal nanoparticles have been developed by introducing the elastic compounds into the shell and the rigid compounds into the core via Semi-continuous seed emulsion polymer method. these core/shell nanoparticles can facile self-assemble into large-scale dense ordered structure film via dried at room temperature due to the relatively low glass transition temperature (Tg) of the shell layers. The as-formed papers not only possess the capacity to solvent (water/ethanol) rewritable and multicolor painting, but also can rapidly reversible mechanochromic. With these outstanding features, it can be concluded that this kind of novel multifunctional PCs papers can be served as a promising candidate for next-generation rewriteable and environment-friendly papers, anti-counterfeiting tags and smart tunable bio-sensors, etc. [Display omitted] Photonic crystals film that possesses periodic dielectric structure have shown great prospect in developing environmentally friendly paper alternatives due to the unique properties of dye free and non-photobleaching, but their practical application is limited by the weak interaction between colloidal particles. Although some progress has been obtained, it is still a challenge to develop photonic paper with the desired mechanical and optical properties. Herein, multifunctional hard core/soft shell nanoparticles with controlled size are fabricated by semi-continuous seed emulsion polymerization method. Compared with convention colloidal particles, these core/shell nanoparticles can facile self-assemble into large-scale dense ordered structure film via dried at room temperature due to the relatively low glass transition temperature (Tg) of the shell layers. The facile fabrication route enables the continuous high-through put production of the photonic papers. The as-formed papers not only possess the capacity to solvent (water/ethanol) rewritable and multicolor painting, but also can rapidly reversible mechanochromic. Moreover, due to the good compatibility of core/shell interface, these photonic films possess excellent mechanical properties, demonstrating that this multifunctional film makes the fabrication of novel robust rewritable papers possible and enables visual monitoring of deformation degree. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel route to carbon quantum dots (CQDs) of customized surface functionality. • CQDs with amine functionality obtained from modified paper precursors. • Amine functionalized CQDs demonstrated as efficient probes for DNA binding studies. We report a novel synthesis route for preparing carbon quantum dots (CQDs) of customized surface functionality from readily available precursors. The synthetic strategy is based on the chemical modification of paper precursors prior to preparing CQDs from them. The pre-synthesis modification of paper precursors with (3-Aminopropyl) triethoxy silane (APTES) enabled us to synthesize CQDs with amine functional groups on the surface. The silane coupling via condensation between the ethoxy group of APTES and the cellulose hydroxyl group on the paper resulted in the tethering of amine groups on the paper substrates, which are retained as surface-bound species during the synthesis of CQDs from the modified paper. Amine functionalization on the surface of CQDs helped us use them in applications such as DNA binding. We analyzed the interaction of CQDs with calf thymus DNA (CT-DNA), and the results imply their propensity as an efficient biological probe. The synthetic strategy presented here can also be extended to other functional groups. [ABSTRACT FROM AUTHOR]

[Display omitted] The O-vacancy Bi 2 WO 6 /SrTiO 3 heterojunction photocatalyst with Z scheme photogenerated electron transfer mechanism was loaded on cellulose fibers to construct a visible light-responsive photocatalytic composite paper for efficient and recyclable degradation of organic dyes in water. The introduction of O vacancies in Bi 2 WO 6 by alkali etching increased the utilization rate of Bi 2 WO 6 for visible light and achieved effective regulation of the energy band structure and Fermi level, which transformed Bi 2 WO 6 /SrTiO 3 type-II heterojunction into Z scheme heterojunction. The light-excited electrons in the conduction band of O-vacancy Bi 2 WO 6 directly migrated to the valence band of SrTiO 3 , which improved the separation efficiency of photogenerated carriers and maximized the redox capability of semiconductors. Compared with other control papers, O-vacancy Bi 2 WO 6 /SrTiO 3 paper exhibited the best photocatalytic performance, and its degradation rate for rhodamine B could reach 71.1% under 100 min of Xe lamp irradiation. The O-vacancy Bi 2 WO 6 /SrTiO 3 paper also showed good photocatalytic cycle stability. Loading heterojunction on the cellulose fibers solved the problem of poor reusability and difficult in recovery for powder semiconductor photocatalyst in practical applications. This study provides a novel strategy for constructing Z scheme heterogeneity on cellulose fibers to prepare composite paper with high photocatalytic activity and good reusability. [ABSTRACT FROM AUTHOR]

[Display omitted] Enhancing the interfacial dispersion and suspension stability is crucial for magnesium hydroxide (Mg(OH) 2) nanomaterials in the long-term deacidification of paper-based cultural relics. However, because of the low specific surface area and the poor solvent compatibility of as-prepared large-sized Mg(OH) 2 , it often tends to agglomerate and settle down during the usage and storage, that is harmful for paper protection due to its unevenly deacidification and nonuniformly distribution on paper cellulose. Herein, we propose a feasible preparation of colloidal Mg(OH) 2 ultrathin nanoflakes with high dispersion stability via a simple one-step surfactant-assisted strategy. The surfactant acts as both a structure-direct agent to confine the growth of Mg(OH) 2 with rich active sites and a surface modifier to enhance its solvent adaptability and dispersion stability, avoiding the common fussy procedure with additional steric stabilizer. Owing to the evenly interaction with free acid species therein and the uniformly distribution on the paper fiber as alkaline reserve, the as-obtained Mg(OH) 2 presents the superior paper protection performance characterized by its safer pH of 7.29 for the original aged paper (pH = 5.03) and the excellent long-term anti-acidification effect with competitive pH of 5.47 after accelerated-aging at 105 °C for 5 months. Furthermore, Mg(OH) 2 nanoflakes with surfactant-modified structure also endue them as an improved flame retardant for multifunctional paper protection. The protection with Mg(OH) 2 has little effect on the paper surface properties and cellulose crystallinity, in line with the principle of least intervention. This work will put forward a feasible way toward colloidal Mg(OH) 2 nanoflakes with excellent paper protection performance, shedding light on the development of emerging protection materials for paper-based cultural relics. [ABSTRACT FROM AUTHOR]

[Display omitted] Investigation of sluggish redox kinetics and polysulfide shuttling is crucial to design advanced lithium sulfur battery. Cerium oxide (CeO 2) has remarkable polysulfide adsorption capability and has been recently investigated in lithium sulfur battery application. With the goal of bridging towards commercialization of lithium sulfur battery, cellulose paper derived carbon fiber decorated with CeO 2 nanorods using hydrothermal method has been fabricated and used as interlayer material for lithium sulfur battery. In this novel design, the carbon fiber provides physical confinement with its 3-D interconnected conductive structure and CeO 2 adsorbs lithium polysulfides chemically to reduce shuttle effect to achieve long lifetime and high capacity for lithium sulfur battery. With a sulfur content of 2 mg, a high capacity of 1177 mAhg−1 was achieved at 0.2C with an excellent stability of only 0.11% capacity decay per cycle over 300 cycles. The improved performance is attributed to the binding of lithium polysulfides by CeO 2 and the blocking of polysulfides physically by the compact conducting carbon fiber. [ABSTRACT FROM AUTHOR]

[Display omitted] Soybean-oil-based polymer is a promising bio-based water barrier coating on paper packaging but the application is challenged due to its poor water dispersibility. In this present study, 3-aminopropyltriethoxysilane (APTES) modified nanocrystalline cellulose (NCC) was used to implement a stable dispersion of acrylated epoxidized soybean oil (AESO) in water and thus synergistically improved the water vapor barrier properties after coating on paper. APTES-NCC was successfully prepared, and displayed a better interface compatibility with AESO through the Michael addition reaction. Compared with NCC, APTES-NCC displayed an improved hydrophobicity and wettability with AESO, with an increase of contact angle from 38.0° to 76.4°, and a decrease of interfacial tension from 91.5 ± 3.5 mN/m to 82.9 ± 1.8 mN/m. As an emulsifier, APTES-NCC can be more effectively adsorbed on the oil–water interface to form a more stable emulsion than NCC, with a decrease of AESO droplets size from 4.8 µm to 3.1 µm, and a remarkable improvement in static and centrifugal stability. In rheological measurement, the APTES-NCC/AESO emulsion showed a wider linear viscoelastic region (3.4%), better viscoelasticity and thermal curing properties than that of NCC/AESO emulsion, which further explained that the stability of APTES-NCC/AESO emulsion were improved. Therefore, APTES-NCC/AESO emulsion as a coating on paper cured into a continuous barrier film can effectively improve the water vapor barrier properties of paper, and the water vapor transmission rate (WVTR) of paper can be reduced from 1392.8 g/m2•24 h (NCC/AESO emulsion-coated) to 1286.3 g/m2 24 h (APTES-NCC/AESO emulsion-coated), both are significantly lower than that of base paper (1926.7 g/m2•24 h). CLSM testing showed that APTES-NCC could interact effectively with AESO to forming a tight barrier on paper surface and at the same time, sealing the pores inside the paper to resist water vapor penetration. The high-stable AESO emulsion prepared by APTES-NCC is expected to facilitate the utilization of NCC and AESO as a value-added material in making sustainable barrier packaging. [ABSTRACT FROM AUTHOR]

Ideally, if the corrosion resistance coating on carbon paper (CP) can be endowed with the self-healing property, the service life and the reliability of the carbon paper will be greatly increased as the gas diffusion layer. In this paper, different cycles of s branched poly (ethyleneimine) (bPEI) and poly (acrylic acid) (PAA) were modified on the surface of the carbon paper via layer-by-layer (LbL) self-assembly technology. The prepared polyelectrolyte multilayered coatings can not only protect the carbon fiber from corrosion, but also take advantages of the surrounding water to quickly repair themselves after damaged. The effects of the assembly cycles on morphology, resistance, air permeability and the contact angle of carbon papers were investigated, then the differences of the carbon papers in electrolysis process were explored. The results reveal that all the prepared coatings can protect carbon papers from corrosion, while when the assembly cycles was 10, the coatings are most efficient. [ABSTRACT FROM AUTHOR]

Flexible and conductive polypyrrole (PPy) paper shows the potential use in electromagnetic shielding, antistatic packaging, and electrochemical materials due to its low cost and facile manufacturing procedure. However, the poor mechanical strength and relatively low electrical stability of PPy paper is still challenging. In this study, we use horseradish peroxidase polymerized sulfonated alkaline lignin (HSAL) as a dispersant and dopant for PPy and demonstrate mechanically strong and electrically stable PPy paper by a combination of multiple impregnations and in-situ polymerization. The abundant sulfonic, carboxyl, and phenolic hydroxyl groups of HSAL could significantly improve the interfacial interaction between cellulose fibers and PPy. Meanwhile, its high molecular weight facilitated the uniform distribution of pyrrole along the fiber axial direction during in-situ polymerization. As a result, the resulting PPy paper exhibits enhanced mechanical properties and electrical stability, as well as high conductivity (24.84 S cm−1). More significantly, we investigated the influences of the dosage of HSAL and the cycles of multilayer impregnations on the electrical and mechanical properties of PPy paper. This work sheds light on the design and fabrication of flexible and conductive PPy paper with superior mechanical robustness and stable electrical performance. [ABSTRACT FROM AUTHOR]

• Nacre-like GO-PTA paper is prepared by evaporation-induced self-assembly method. • Fire sensor-based GO-PTA exhibits ultrasensitive and durable warning response. • Enhancement in fire resistance of GO is attributed to in situ phosphorus doping. A novel nacre-like flame-retardant paper based on graphene oxide (GO), and phytic acid (PTA) is fabricated via evaporation-induced self-assembly. This facile method is time saving and low energy consuming. A facile approach is proposed to improve thermal oxidative stability of GO paper by in situ phosphorus doping during flame exposure. Then fire-alarm system is designed based on the high-temperature thermal reduction characteristic of GO. The GO paper functionalized with PTA (GO-PTA) can provide ultrasensitive, reliable and longtime fire early-warning signal. Fire alarm can be triggered at approximately 0.50 s when GO-PTA samples are attacked by fire. Phosphorus atoms are in situ doped into graphene layers during fire exposure, endowing GO-PTA paper with outstanding thermal oxidative stability, and thus alarm duration time of GO is greatly improved. The work develops advanced fire detection and early-warning sensors that provide reliable and continuous signals, which provide more available time for fire evacuation. [ABSTRACT FROM AUTHOR]

Paper is kind of essential materials in our daily life. However, it can be easily destroyed by water owing to its superhydrophilic surface. Here, we reported a simple and green fabrication of coloured superhydrophobic paper via swelling and approximate dissolution of cotton followed by precipitation of cellulose and doping coloured stearates. The obtained paper exhibited uniform colour and superhydrophobicity, of which the colour was consistent with the doped stearates owing to the adhesion of stearate powders to the tiny floc fiber surface and we proved that the superhydrophobicity could not be damaged after abrasion resulting from the inner and outer superhydrophobicity and the increased surface roughness. This coloured superhydrophobic paper would be avoided from moisture damage and may be useful in different fields. [ABSTRACT FROM AUTHOR]

The demand for high-quality graphene for electronic applications is increasing due to its high carrier mobility and electrical conductivity. In this connection, printing technology is a reliable method towards the fabrication of conductive, disposable graphene-based electrode for low-cost sensor application. Herein, we aimed to report the synthesis of high-quality graphene nanosheets obtained by electrochemical exfoliation of biomass-derived from corn cob. The conductive ink was prepared from this exfoliated graphene and was utilized for the preparation of paper-based graphene electrode towards double stranded DNA (dsDNA) sensor application. This paper, based graphene electrode opens the possibility of direct electrochemical analysis of analyte without any sample preparation. In this study, two irreversible oxide peaks were obtained from paper-based printed graphene electrode, corresponds to oxidation of guanine (G) and adenine (A) of dsDNA in the linear range of 0.2 pg mL−1 to 5 pg mL−1 with the detection limit of 0.68 pg mL−1 and the sensitivity of 0.00656 mA pg−1 cm−2. Further, a small-scale printable circuit is fabricated using this graphene shows good conductivity of 1.145x103(S/m). [ABSTRACT FROM AUTHOR]

• Ni@FP photocatalytic material was firstly prepared by a facile and low-cost method. • Ni@FP photocatalyst had strong magnetic properties and can be easily recycled. • Ni@FP photocatalyst's photocatalytic degradation rate reached to 93.40% within 5 min. • Ni@FP photocatalytic material possessed strong antibacterial ability. Photocatalytic materials have been widely used to remove dyes from printing and dyeing wastewater. However, difficulty in recycling of photocatalysts is the great concern in the real catalytic applications, which significantly raises the application cost. This study developed a low-cost catalyst by loading magnetic Ni onto filter paper (FP) via an easy going in-situ reaction. The characterization results displayed that the Ni particles were uniformly anchored onto the FP. The Ni@FP material presented a strong magnetic ability which was evidenced by a saturation magnetization (Ms) of 5.014 emu·g−1, a remanent magnetization (Mr) of 2.067 emu·g−1 and a coercivity (Hc) of 133.868 Oe. Meanwhile, the magnetic Ni@FP material displayed a recyclable advantage in photocatalytic degradation of methyl orange (MO) via an external magnetic field. There existed an optimal photocatalytic degradation rate of 93.40% within 5 min when MO concentration was 15 mg·L−1 at pH 8.0. Three cycle experiments confirmed that the Ni@FP possessed a satisfied stability and recycling ability. Moreover, the Ni@FP material presented a strong antibacterial activity which can prevent it from being contaminated by microorganisms. The versatility of the newly proposed photocatalyst in this study demonstrated its great application prospect in dyeing wastewater treatment. [ABSTRACT FROM AUTHOR]

Porous carbon encapsulated non-precious metal nanocatalysts have recently opened the ways towards the development of high-performance water remediation and energy conversion technologies. Herein, we report a facile, scalable and green synthetic methodology to fabricate porous carbon encapsulated transition metal nanocatalysts (M@TP: M = Cu, Ni, Fe and Co) using commercial tissue paper. The morphology, crystalline structure, chemical composition and textural properties of the M@TP nanocatalysts were thoroughly characterized. The catalytic activity of the M@TP nanocatalysts was investigated for the degradation of Congo red (CR) via peroxymonosulfate activation. Co@TP-6 was found to be the most active catalyst allowing 97.68% degradation in 30 min with a higher rate constant of 0.109 min−1. The nanocatalysts also displayed a carbon shell thickness-dependent electrocatalytic hydrogen evolution reaction (HER) activity, most likely due to the shielding effect of the carbon layers over the electron transfer (ET) processes at the metal core/carbon interfaces. Remarkably, the Ni@TP-6 electrocatalyst, with the smaller carbon shell thickness, showed the best electrocatalytic performance. They delivered an ultralow onset potential of −30 mV vs RHE, an overpotential of 105 mV at a current density of 10 mA·cm−2 and an excellent electrochemical stability to keep the 92% of the initial current applied after 25000 s, which is comparable with the HER activity of the state-of-the-art Ni-based catalysts. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Hypothesis The rate of stain growth of a sessile droplet deposited on paper has been previously studied (Kissa, 1981; Danino and Marmur, 1994; Kawase et al., 1986; Borhan and Rungta, 1993) but is not fully understood. In particular, the mechanism by which the abrupt decrease in growth rate occurs is unknown. This process is expected to follow a model where the disappearance of the droplet is represented by a change to the boundary condition at the droplet-paper interface when the volume of the fluid inside the paper is equal to the volume of the simulated droplet. Experiments The stain size of sessile droplets on paper was monitored against time. A series of fluids varying in surface tension and viscosity was studied. The kinetics of stain growth was modelled and compared with experiments and existing models of stain growth. Findings The measured stain area formed by a sessile droplet deposited on paper follows a two regime mechanism (Danino and Marmur, 1994). In the initial regime, the dynamics are governed by the filling of pores. However, in the later stage, the process is influenced by the emptying/redistribution of fluid. Simulations show that experimental results are well described by a model that identifies the change in boundary conditions after the droplet is no longer present above the paper, coupled with the change to a redistribution dominated mechanism. [ABSTRACT FROM AUTHOR]

An ultrafast and efficient strategy is developed to produce homogeneous GQDs through instantaneous photothermal gasification and recrystallization, revealing the promising potential for large-scale production. [Display omitted] Graphene quantum dots (GQDs) are attractive fluorescent nanoparticles that have wide applicability, are inexpensive, nontoxic, photostable, water-dispersible, biocompatible and environmental-friendly. Various strategies for the synthesis of GQDs have been reported. However, simple and efficient methods of producing GQDs with control over the size of the GQDs, and hence their optical properties, are sorely needed. Herein, an ultra-fast and efficient laser writing technique is presented as a means to produce GQDs with homogeneous size from graphene produced by the instantaneous photothermal gasification and recrystallization mechanism. Controlling the laser scan speed and output power, the yield of GQDs can reach to be about 31.458 mg/s, which shows promising potential for large-scale production. The entire process eliminates the need for chemical solvents or any other reagents. Notably, the prepared laser writing produced GQDs (LWP-GQDs) exhibit blue fluorescence under UV irradiation of 365 nm and the Commission Internationale de L'Eclairage (CIE) chromaticity coordinates is measured at (0.1721, 0.123). Overall, this method exhibits superior advantages over the complex procedures and low yields required by other existing methods, and thus has great potential for the commercial applications. [ABSTRACT FROM AUTHOR]

Mechanisms of inkjet ink spreading and absorption on a coated paper have been studied using a polyelectrolyte multilayering technique. By applying alternating sequences of cationic and anionic polyelectrolyte layers on a mineral coated paper, the role of the interfacial chemistry was evaluated. The polyelectrolyte multilayer was created to imitate a thin resin-like liquid-absorptive layer and to clarify the role of the charge of the protruding polyelectrolyte layer on ink spreading and colorant fixation. The formation of a thin polyelectrolyte layer and coating coverage was confirmed by X-ray photoelectron spectroscopy (XPS). A submolecular mechanical imaging of the polyelectrolyte complexes with an atomic force microscope (AFM) revealed differences in modulus and different nanosize agglomerates were identified which were ascribed to polyion complexes. The polyelectrolyte coatings significantly affect the solid–liquid interaction and particularly the ink spreading revealed as intercolor bleeding and wicking. The interfacial interaction between the ink and the applied polyelectrolyte layers showed differences between dye- and pigment-based colorants, which could be emphasized by the polyelectrolyte chemistry. [ABSTRACT FROM AUTHOR]

[Display omitted] From environmental waste to energy storage, waste boxes converted into conductive electrodes to further grow active materials has been an interesting way of upcycling. In this study, we transformed waste boxes of KIMTECH Kimwipes® into conductive f-MWCNTs light and flexible substrate (LFS) as current collectors. Then, undoped and P-doped active materials consisting of layered quadruple hydroxides (LQH) was successfully grown on the conductive f-MWCNTs/LFS. Specifically, P-doped f-MWCNTs/LQH demonstrates 1.8 times the capacitance of an undoped f-MWCNTs/LQH. Such conversion of waste boxes not only offers a useful way of reusing waste papers which commonly ends in landfills, but the inexpensive method also offers an extreme way of cutting cost in developing conductive substrates. Also, the effective strategy of synthesizing active materials on the conductive f-MWCNTs/LFS paves its way as potential cheap electrodes of the future generation. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract In this work, we constructed a sensing system on Janus paper with hydrophilic side and hydrophobic side via depositing polymer precursor onto one side of qualitative filter paper. Water in humid environment (including liquid water, condensed moisture airflow and gaseous humid atmosphere) will be captured and gathered in the hydrophilic region of Janus paper due to the asymmetric hydrophobicity and hygroscopicity, which can induce the novel directional deformation. Additionally, MWCNTs (multiwalled carbon nanotubes) were loaded onto hydrophobic region beforehand to construct conductive network. The resistance of the conductive network changes synergistically as the Janus paper deforms in humid environment. Thus, the novel Janus paper realized the induction of environment humid factors, and conversion from the deformation signals to the desirable electric signals. The Janus paper also shows excellent stability in cycle use. [ABSTRACT FROM AUTHOR]

Hypotheses (1) The equilibrium size and characteristics of a radially wicked fluid on porous material such as paper is expected to be dependent on the fluid properties and therefore could serve as a diagnostic tool. (2) The change in wicked stain size between biological fluids is dependent on a change in solid-liquid surface interfacial energy due to protein adsorption. Experiments Sessile droplets of increasing volume of blood, its components, and model fluids were deposited onto paper and the equilibrium stain size after coming to a halt was recorded. The contact angle of fluid droplets on model cellulose surfaces was measured to quantify the effect that blood protein adsorption at the solid-liquid interface has on radially wicked equilibrium size. Finally the significance of droplet evaporation for the time scale of interest was analysed. Findings The final stain area of all fluids tested on paper scales remarkably linearly with droplet volume. Different fluids were compared and the gradient of this linear relation was measured. Model fluids varying in surface tension and viscosity all behave similarly and exhibit a constant gradient. Blood and its components produce smaller stains, demonstrated by lower gradients. The gradient is a function of protein concentration, thus the mechanism of this phenomenon was identified as protein adsorption at the cellulose-liquid interface. The slope of the area/volume relationship for droplets is an important quantitative mechanistic variable. [ABSTRACT FROM AUTHOR]

In this work, three adsorbents were produced by using as precursor primary paper mill sludge and applying KOH, NaOH or ZnCl 2 as chemical activating agents (PS800-10KOH, PS800-10NaOH and PS800-10ZnCl 2 ) and subjected to pyrolysis. The produced materials were tested for removal of fluoxetine from water, reported as one of the most persistent pharmaceuticals in the aquatic environment. Also, primary sludge pyrolysed under the same conditions but without activation (PS800-10) and a commercial activated carbon (PBFG4) were studied for comparison. Physical and chemical properties of the materials were determined and adsorption kinetic and equilibrium studies were performed in batch experiments. Equilibrium studies allowed testing the capacity of the produced materials for adsorb fluoxetine-HCl, showing no apparent correlation between the S BET areas and the adsorption capacities of the materials. The maximum adsorption capacity (mg g −1 ) was of 191.6 ± 4.8 for PS800-10KOH; 136.6 ± 9.6 for PS800-10NaOH; 28.4 ± 0.3 for PS800-10ZnCl 2 ; 120.4 ± 2.5 for PS800-10 and 96.2 ± 1.0 for PBFG4. It was demonstrated that many factors influence the removal of fluoxetine from solution and that the surface area is not the main factor in the process. Also the activation process did not enhance the properties of the produced materials. [ABSTRACT FROM AUTHOR]

[Display omitted] The pulp and paper sectors are thriving yet pose significant environmental threats to water bodies, mainly due to the substantial release of pollutants. Lignin-derived compounds are among the most problematic of these contaminants. To address this issue, we present our initial results on utilizing organic semiconductor photocatalysis under visible light for treating lignin-derived compounds. Our investigation has been centered around creating a green and cost-effective organic semiconductor photocatalyst. This catalyst is designed using a structure of bagasse cellulose spheres to support PM6 (poly[(2,6-(4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)benzo[1,2- b :4,5- b' ]dithiophene))– co -(1,3-di(5-thiophene-2-yl)-5,7-bis(2-ethylhexyl)-benzo[1,2- c :4,5- c' ]dithiophene-4,8-dione))]: MeIC (3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-cyclopentane-1,3-dione[ c ]-1-methyl-thiophe))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3- d:2′ , 3′-d' ]-s-indaceno[1,2- b :5,6- b' ]-dithiophene)). This photocatalyst demonstrates remarkable efficiency, achieving over 91 % degradation of lignin-derived compounds. The superior photocatalytic performance is attributed to three main factors: (1) The ability of PM6 to broaden MeIC's absorption range from 300 to 800 nm, allowing for effective utilization of visible light; (2) the synergistic interaction between PM6 and MeIC, which ensures compatible energy levels and a vast, evenly spread surface area, promoting charge mobility and extensive donor/acceptor interfaces. This synergy significantly enhances the generation and transport of carriers, resulting in a high production of free radicals that accelerate the decomposition of organic materials; (3) The deployment of PM6:MeIC on biomass-based carriers increases the interaction surface with the organic substances. Notably, PM6: MeIC showcases outstanding durability, with its degradation efficiency remaining between 84 % and 91 % across 100 cycles. This study presents a promising approach for designing advanced photocatalysts aimed at degrading common pollutants in papermaking wastewater. [ABSTRACT FROM AUTHOR]

Highly catalytic two dimensional and metal-doped two-dimensional nanomaterials (MoS 2 and NiMoS) were deposited over free-standing graphene (FSG) paper using electrodeposition method and subsequently used as a counter electrode in quasi solid-state dye-sensitized solar cells (q-DSSCs). The replacement of FTO by FSG facilitates high electrical conductivity and electrodeposited metal sulphides provide electrocatalytic activity. The morphology, structural phase formation and chemical composition of FSG-MoS 2 and FSG-NiMoS were investigated using FESEM, XRD, Raman and XPS analysis. The electrochemical behavior of metal sulphide decorated FSG cathodes is investigated using an electrochemical workstation and their effects on the photo-conversion efficiency of DSSCs were assessed. NiMoS with FSG substrate is an intriguing counter electrode material that can be utilized at low fabrication cost than the conventional platinum-based counter electrodes. FSG along with the metallic-two dimensional nanoparticles (NiMoS) functions as an effective catalytic material thereby allowing DSSCs to achieve enhanced efficiency of ∼7% to provide better alternative of FTO and Pt. [ABSTRACT FROM AUTHOR]

Hypothesis Due to their highly retentive properties, innovative recently developed, semi-interpenetrated hydrogels made up of poly(vinyl pyrrolidone) (PVP) chains embedded in a poly(2-hydroxyethyl methacrylate) (p(HEMA)) network should be efficiently used as cleaning material for fragile and degraded paper artworks. In restoration practice, indeed the wet cleaning of these artworks is usually performed by immersion of paper in water, a procedure which may lead to several drawbacks, including paper fibers swelling and dissolution of water-soluble original components. Experiments This class of gels were yet presented in literature, but their interactions with paper materials and ability to be spiked with active enzymes (as cleaning agents), have not been analyzed. To establish the suitability of these hydrogels as paper cleaning materials, first, a rheological and microstructural characterization of the gels was performed. Moreover, diffusion of macromolecules inside gels was studied using fluorescence microscopy, to check if these innovative hydrogels can be used as carriers for hydrolytic enzymes. Indeed, pastes and glues are usually found in old paper artworks, and their removal is a very delicate operation that requires a selective action, which is granted by specific hydrolytic enzymes. At the same time, spectroscopic analyses on paper samples under investigation before and after cleaning treatment has been performed, thus assessing the capabilty of these gels as cleaning materials. Findings With the aim of demonstrating the versatility of these hydrogels, several case studies, i.e., the removal of grime and water-soluble cellulose degradation byproducts, the removal of animal glue and the removal of starch paste from real samples, are presented. Results obtained with these gels have been compared to those obtained by using another gel used for paper artworks cleaning, i.e., Gellan gel. [ABSTRACT FROM AUTHOR]

A macroscopic urea-functionalized CdS (CdS-U) is synthesized for the first time. The CdS-U material is formed through the interaction between NH 2 / NH groups on urea and COO − groups on sodium oleate-capped CdS nanoparticles (CdS-So NPs). The CdS-U material exhibites excellent visible light photocatalytic activity and plasticity and has the potential to be produced as rewritable papers. It is convenience to produce a large-scale film by CdS-U. Letters can be written on the CdS-U film and disappear through a dissolution-irradiation process, and then the CdS-U film can be recycled by drying. This novel CdS-U material might be of interest and provide a new chance to advance the application of visible light photocatalyst on rewritable papers. [ABSTRACT FROM AUTHOR]

[Display omitted] The commercialization of lithium metal batteries (LMBs) is encountering significant challenges due to the electrolyte incompatibility and poor mechanical properties of polyolefin separators, as well as the hazardous growth of lithium dendrites at the anode. Simultaneously, the development of safe and environmentally-friendly separators has become a central focus in rechargeable battery technology. In this study, we introduce a novel Janus separator (CP@SiO 2), featuring a composite structure with cellulose paper (CP) as the base layer and electrospun polyvinylidene fluoride (PVDF) nanofibers as the top layer. The nanofibers are uniformly coated with mesoporous SiO 2 nanoparticles through hydrogen bonding. The CP@SiO 2 separator leverages its three-dimensional lithium-ion channels and rigid ceramic particles to enhance electrolyte retention and stabilize lithium metal anodes (LMA). Shielded by this separator, LMA exhibits an impressive cycling performance, enduring a current density of 2 mA cm−2 for 350 h without short-circuiting, effectively doubling the cycle life compared to conventional PP separators. Furthermore, the Li/LiFePO 4 cell utilizing the CP@SiO 2 separator demonstrates a high capacity of 101 mAh·g−1 at 5C, with 90 % capacity retention after 1000 cycles. This outstanding electrochemical performance is attributed to the compatible anode/separator interface and the effective inhibition of lithium dendrite growth. The research presented in this work capitalizes on a synergistic configuration design, offering a promising pathway towards the development of high-safety and advanced lithium-ion separators. [ABSTRACT FROM AUTHOR]

Recycled paper with superhydrophobicity and flame-retardancy has been demonstrated here due to the synergistic action of dopamine-silica trimethylsilyl modified gel powder and stearic acid modified Mg(OH) 2 . This multifunctional recycled paper displays great self-cleaning and anti-fouling ability and can be used for oil-water separation. Surprisingly, the absorbed organic can be reused as fuel via simple combustion method for multiple cycles. This work will not only expand the usable range of paper but also ease the energy and environment crisis. [ABSTRACT FROM AUTHOR]

In this work, we report atomic-scale reconstruction processes in Fe-Ce oxide-based composites (hydrothermally precipitated at Fe-to-Ce dosage ratios of 1:0, 2:1, 1:1, 1:2, and 0:1), upon treatment at 300 °C. The structural changes are correlated with the adsorptive removal of arsenate, phosphate, fluoride, bromide, and bromate. The presence of the carbonate-based Ce-component and surface sulfate in precursor samples creates favorable conditions for phase transformation, resulting in the formation of novel (unknown) layered compounds of Fe and Ce. These compounds are of the layered double hydroxide type, with sulfate in the interlayer space. In spite of general awareness of the importance of surface area in adsorptive removal, the increase in surface area upon thermal treatment did not increase adsorption of the studied anions. However, EXAFS simulations and the adsorption tests provided evidence of regularities between local structures of Fe in composites obtained at 80 and 300 °C and adsorption performance of most studied anions. The best adsorption of tetrahedral anions was demonstrated by samples whose simulated outer Fe shells resulted from oscillations from both O and Fe atoms. In contrast, the loss of extended x-ray absorption fine structure was correlated with the decrease of adsorptive removal. Both Fe K-edge and Ce L 3 -edge EXAFS suggested the formation of solid solutions. For the first time, the utilization of extended x-ray absorption fine structure is suggested as a methodological approach (first expressed in the companion paper) to estimate the surface reactivity of inorganic materials intended for use as anion exchange adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] Although thousands of superhydrophobic composites have been reported, it is still a challenge to develop eco-friendly superhydrophobic materials by a simple and low-cost strategy. Here, a paper-based superhydrophobic material was prepared by carbon fiber powders and polydimethylsiloxane through a facile spraying method. This obtained material has excellent liquid resistance and self-cleaning properties, whose contact angle reaches 155°. In addition, it possesses excellent photothermal conversion characteristics with a stable surface temperature of 73.4 °C and good water evaporation performance with an evaporation rate up to 1.08 kg/(m2·h) under one solar intensity (100 mW/cm2). Also, it has outstanding self-deicing performance, whose deicing time is 120 s earlier than that of the untreated surface under one solar intensity. An adaptability test shows this strategy of functional coatings can also be applied to other fiber substrates (coating paper, kraft paper, non-woven fabric, paulownia veneer, etc.). Overall, this superhydrophobic material has a promising application prospect in many fields such as waterproof packaging, deicing materials, water evaporation materials, etc. [ABSTRACT FROM AUTHOR]

[Display omitted] • Trimetallic NiCoFe PBAs are electrodeposited homogeneously on CFP as precursors. • The NiCoFe-Se NCs grown on CFP as self-supported electrode for OER. • The NiCoFe-Se/CFP exhibits remarkable OER activity and desirable stability. • Trimetallic element regulation effectively improves the OER activity of selenides. The progress of inexpensive, high-efficiency, and steady oxygen evolution reaction (OER) electrocatalysts is of great importance to promoting water splitting for green hydrogen production. Herein, tri-metallic NiCoFe selenide catalyst backed up by carbon fiber paper (CFP) was synthesized by a facile selenization of NiCoFe Prussian blue analogues (PBAs) for OER in alkaline solutions. The NiCoFe-Se/CFP inherited the porous nanostructure of the metal-organic frameworks (MOFs) precursors prepared by rapid cyclic voltammetry electrodeposition. Benefiting from the 3D hierarchical porous structure, optimized electronic structure of NiCoFe selenides and high conductivity, the synthesized electrocatalyst exhibits outstanding catalytic activity to the corresponding mono-metallic or bi-metallic selenides. Specifically, the NiCoFe-Se/CFP electrode demands an overpotential of 221 mV to attain the 10 mA cm−2 current density in 1.0 M KOH solution and a low Tafel slope of 38.6 mV dec-1. The prepared catalyst also displays good stability and durability. These findings prove a feasible strategy to further improve the catalytic activities of non-precious metal based OER electrocatalysts by the cooperation of structure design and chemical component modification. [ABSTRACT FROM AUTHOR]

Environmentally switched superwetting surfaces that can be used for separating various oil/water mixtures are of particular interest due to the increasing difficulty and complexity in oily wastewater treatment. Here, a novel fluorine-free pH-responsive coating is prepared by surface modification of SiO 2 nanoparticles with dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride and (N, N-dimethyl-3-aminopropyl) trimethoxysilane. With the assistance of polyethylene imine as a binder, such coating can be used for different porous substrates, e. g. cotton fabric and filter paper, to develop separation materials having tunable superhydrophilicity/superhydrophobicity and high antibacterial property. Due to the well-controlled surface wettability upon the pH variation, the as-prepared materials can effectively separate various types of oil/water mixtures with efficiency higher than 99.9%, including the layered oil/water mixture, water-in-oil emulsions and oil-in-water emulsions stabilized by different types of surfactants. Additionally, the materials can resist strong acid/base solutions and various organic solvents as well as 50-cycle mechanical abrasion and 120-cycle tape-peeling without losing anti-wetting performance. Featuring the tunable surface wettability, chemical/mechanical robustness, and antibacterial activity, such coating holds promising applications for treating various oil/water mixtures in harsh and biological-contamination conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] Li-rich dual-phase Li-Cu alloy is a promising candidate toward practical application of Li metal anode due to its in situ formed unique three-dimensional (3D) skeleton of electrochemical inert LiCu x solid-solution phase. Since a thin layer of metallic Li phase appears on the surface of as-prepared Li-Cu alloy, the LiCu x framework cannot regulate Li deposition efficiently in the first Li plating process. Herein, a lithiophilic LiC 6 headspace is capped on the upper surface of the Li-Cu alloy, which can not only offer free space to accommodate Li deposition and maintain dimensional stability of the anode, but also provide abundant lithiophilic sites and guide Li deposition effectively. This unique bilayer architecture is fabricated via a facile thermal infiltration method, where the Li-Cu alloy layer with an ultrathin thickness around 40 μm occupies the bottom of a carbon paper (CP) sheet, and the upper part of this 3D porous framework is reserved as the headspace for Li storage. Notably, the molten Li can quickly convert these carbon fibers of the CP into lithiophilic LiC 6 fibers while the CP is touched with the liquid Li. The synergetic effect between the LiC 6 fibers framework and LiCu x nanowires scaffold can ensure a uniform local electric field and stable Li metal deposition during cycling. As a consequence, the CP capped ultrathin Li-Cu alloy anode demonstrates excellent cycling stability and rate capability. [ABSTRACT FROM AUTHOR]

The oxygen-rich vacancies and crystalline/amorphous Ru doping CoCu+Ru 10 -LDH/NF were successfully synthesized using MOF as precursor and template. The combination of heteroatom doping, interface engineering, and defect engineering can significantly improve the conductivity, intrinsic activity, and active site utilization of the catalyst to achieve efficient OER performance. This design concept presented in this paper provides a new way to develop high performance OER electrocatalysts. [Display omitted] Reinforcing the development of efficient and robust electrocatalysts is pivotal in addressing the challenges associated with oxygen evolution reactions (OER) in water splitting technology. Here, an amorphous/crystalline low-ruthenium-doped bimetallic layered double hydroxide (LDH) electrocatalyst (a/c-CoCu + Ru x -LDH/NF) with massive oxygen vacancy on nickel foam was fabricated via ion-exchange and chemical etching, facilitating efficient OER. Among the various catalyst materials tested, the a/c-CoCu + Ru 10 -LDH/NF exhibits remarkable performance in the OER when employed in an alkaline electrolyte containing 1 M KOH. Achieving a minimal overpotential at 10 mA cm−2 of 214 mV, exhibiting a low Tafel slope value of 64.3 mV dec−1 and exceptional durability lasting for over 100 h. Theoretical calculations demonstrate that the electron structure and d-band center of CoCu-LDH can be effectively regulated through the utilization of a strategy possessing abundant oxygen vacancies and a Ru-doped crystalline/amorphous heterostructure. It will lead to optimized adsorption free energy of reactants and reduced energy barriers for OER. The construction strategy proposed in this paper for catalysts with amorphous/crystalline heterointerfaces offer a novel opportunity to achieve highly efficient OER. [ABSTRACT FROM AUTHOR]

As a high-active metal-free electrocatalyst for NH 3 production via NO reduction reaction, honeycomb carbon nanofiber achieves an NH 3 yield of 22.35 μmol h−1 cm−2 with a high Faradaic efficiency of 88.33%. [Display omitted] Electrocatalytic NO reduction is a promising technology for ambient NO removal with simultaneous production of highly value-added NH 3. Herein, we report that honeycomb carbon nanofiber coated on carbon paper acts as an efficient metal-free catalyst for ambient electroreduction of NO to NH 3. In 0.2 M Na 2 SO 4 solution, such catalyst achieves an NH 3 yield of 22.35 μmol h−1 cm−2 with a high Faradaic efficiency of up to 88.33%. Impressively, it also shows excellent stability for 10-h continuous electrolysis. Theoretical calculations reveal that the most active center of functional groups is –OH group for NO reduction with a low energy barrier (ΔG of 0.29 eV) for the potential-determining step (*NO + H → *HNO). [ABSTRACT FROM AUTHOR]