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Cellulose paper derived from plants is used for daily writing and recording and has historically played an important role in promoting cultural dissemination and inheritance. However, it has attracted increasing attention in recent years, serving as a flexible platform or substrate for environment and energy applications, which is attributed to its many inherent advantages such as biocompatibility, biodegradability, sustainability, low cost, and great capability to be modified. With the development of various industries, especially the flexible electronics industry, the demand for two-dimensional (2D) paper-like materials have increased. Several types of inorganic paper are manufactured and have been widely used in many fields. Among them, hydroxyapatite (HAP)-based and carbon-based inorganic paper exhibit unique advantages and have been well applied in certain fields. In addition, there are many composite papers assembled by several raw materials (cellulose fibers, HAP, and carbon), exhibiting excellent characteristics. Cellulose paper is no longer limited to traditional writing applications and has great potential to be used in many aspects, achieving a stunning change in its role. The emergence of inorganic paper and hybrid paper has further demonstrated the application prospects of paper-like two-dimensional materials. Herein, initially, we present the characteristics of three types of paper and composite paper, and then summarize their typical applications in the environment and energy fields. [ABSTRACT FROM AUTHOR]

Solar-driven interfacial steam generation (SISG) has received increasing attention due to its continuous clean water generation under sunlight irradiation with high photothermal conversion efficiency. However, the inevitable waste of solar thermal energy and the poor adaptability of the photothermal material severely restrict its practical application. Herein, we report for the first time the fabrication of flexible and free-standing alkaline-earth metal ios-mediated graphene oxide nanoribbon paper (GONRs paper) by utilizing the ring-opening and cross-linking reactions of GONRs with M (Mg2+, Ca2+, Sr2+ or Ba2+). Owing to the unique structure, the as-created GONRs-M paper embraces all the desirable capabilities, including light absorption, thermal conversion, and wetting ability, and enables continuous clean water production from seawater and simulated wastewater with nearly 91.5% photothermal conversion efficiency under one solar intensity irradiation (1 kW m−2). In addition, complementary heat loss-induced thermoelectricity is harvested alongside SISG, ensuring simultaneous desalination and electricity production with high efficiency. This facile strategy opens an avenue for developing GONR paper-based durable steam generators, not merely for sustainable clean water production, but also for harvesting low-grade waste energy. [ABSTRACT FROM AUTHOR]

The global efforts in electrifying our society drive the demand for low-cost and sustainable energy storage solutions. In the present work, a novel material concept was investigated to enable fabrication of several 10 meter-long rolls of supercapacitor paper electrodes on a pilot-scale paper machine. The material concept was based on cationized, cellulose-rich wood-derived fibres, conducting polymer PEDOT:PSS, and activated carbon filler particles. Cationic fibres saturated with anionic PEDOT:PSS provide a conducting scaffold hosting the activated carbon, which functions as the active charge-storage material. The response from further additives was systematically investigated for several critical paper properties. Cellulose nanofibrils were found to improve mechanical properties, while carbon black enhanced both the conductivity and the storage capacity of the activated carbon, reaching a specific capacitance of 67 F g−1. This pilot trial shows that "classical" papermaking methods are fit for the purpose and provides valuable insights on how to further advance bio-based energy storage solutions for large-scale applications. [ABSTRACT FROM AUTHOR]

Uniformly dispersing silver nanowires (AgNWs) in polymer matrices is of paramount importance for developing high-performance electromagnetic interference (EMI) shielding materials. Herein, new flexible and robust high-efficiency bacterial cellulose (BC)-based EMI shielding papers were developed via a modified step-by-step in situ biosynthesis method, in which, AgNWs were well distributed in the BC network. The BC nanofibers and AgNWs could form an effective entangled network with hydrogen bonding, efficiently strengthening the produced BC/AgNW papers. An electrical conductivity of 608 365 S m−1 was achieved for a BC/AgNW paper with a AgNW content of 36.5 wt%, which is superior to almost all AgNW-containing papers reported so far. Moreover, the BC/AgNW paper could sustain mechanical deformation and vigorous washing, without losing electrical conductivity. Additionally, this paper presents an ultrahigh specific EMI shielding effectiveness of ∼6400 dB mm−1, which is higher than almost all previously reported AgNW-based polymer composites. The proposed approach in this study provides a facile and scalable fabrication route for producing flexible and highly conductive BC/AgNW papers, which are of great potential as electrically conductive components and EMI shielding elements in advanced applications. [ABSTRACT FROM AUTHOR]

Flexible energy storage devices are of significant interest for wearable device applications. In this regard, paper, which is thin, light, flexible, and highly porous, has emerged as a next-generation energy-storage material. Here, we introduce a facile technology for fabricating a supercapacitor based on a single sheet of paper, in which the electrodes are vertically separated by the patterning of hydrophobic barriers. The positive and negative electrodes can be simultaneously sectionalized as active layers and current collectors in a single-layer porous paper supercapacitor, such that the gel electrolyte infiltrates the device without any additional assembly. The solid-state supercapacitor with vertically layered electrodes exhibits a large areal capacitance of 560.2 mF cm−2 at 0.2 mA cm−2 and stable flexibility and foldability. The maximum power and energy densities were 1.597 mW cm−2 and 28.74 μW h cm−2, respectively, which highly exceed those of previously reported multi-sheet paper-based supercapacitors. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) have been widely used for self-powered gas sensors recently. However, limitations such as low sensitivity especially for trace concentrations of NH3 and narrow detection ranges inevitably pose serious challenges. Herein, a kind of highly sensitive self-powered gas sensor based on a PANI/cellulosic hierarchical structure (PC-TENG) was developed to detect NH3 gas. The hierarchical structure provides excellent gas permeability and huge numbers of gas adsorption sites. Meanwhile, the most effective structure design of the integrated self-powered NH3 sensors (PANI acts as the electrode/tribo-material) was identified by a comparison of different structure designs (PANI plays a single role of the electrode or tribo-material, or double roles of the both). Benefitting from the abundant gas adsorption sites, and the coordinate regulation of the PANI's surface tribo-state and impedance caused by protonation–deprotonation of PANI, the rationally designed PC-TENG exhibits outstanding sensing properties, with a minimum detection limit as low as 100 ppb and a maximum limit of 500 ppm, wherein the maximum output voltage and current of the PC-TENG are 23 V and 0.17 μA, respectively. And the sensitivity of the PC-TENG was up to 45.41% ppm−1 from 0.1 to 1 ppm, and 15.17% ppm−1 from 1 to 50 ppm. In particular, the sensitivity for trace concentrations of NH3 (0.1 to 50 ppm) is the highest value among reported studies. In addition, the mature processing technique of commercial nitro-cellulosic paper and its eco-friendly nature further provide the feasibility of large-scale production and application of environmentally friendly self-powered NH3 sensors. [ABSTRACT FROM AUTHOR]

Commercial paper as an indispensable material in our daily life is extremely easily destroyed by water and fire. And obtaining paper with the writable, non-flammable and superhydrophobic properties is still a challenging issue. Inspired from nature, biomimetic nanowires made from hydroxyapatite (HAP) can be used as raw materials to fabricate functional paper. In this study, we present a superior, fire-resistant and repairable superhydrophobic PFDS-paper@ZnO exhibiting remarkable oil absorption–combustion performance. In particular, the layered structure of the paper might be the reason of its excellent superhydrophobicity even after 20 abrasion cycles with sandpaper (400 cW). In contrast, the common paper was destroyed after 5 abrasion cycles with sandpaper under identical conditions. It was observed that the intrinsic fire-resistant nature of the paper was expected to reduce the risk of fire and might be used as an absorbent for flammable oil. On the one hand, such burnt paper can recover its original superhydrophobicity by facile modification after multiple cycles, achieving the repairable performance of its superhydrophobic surface. On the other hand, the burnt paper without subsequent modification exhibits superhydrophilicity in air and also underwater superoleophobicity, which can be used for efficient surfactant-stabilized oil-in-water emulsion separation. This study expands the potential applications of functional paper, which might be a breakthrough for traditional papermaking industries. [ABSTRACT FROM AUTHOR]

Solar-driven evaporators (SDEs) have attracted increasing attention in producing potable freshwater. Developing a multitasking SDE with stable self-floating performance, long-term salt resistance, effective heat management, pollutant degradation capability and good scalability for industrial production is significant but challenging. This work demonstrates the fabrication of a cellulose paper-based SDE with rough photothermal coating, controlled Janus wettability and a hierarchical Fenton catalyst for advanced solar desalination. Through the surface deposition of an urchin-like nanocatalyst and polypyrrole coating, a rough photothermal top layer for enhanced light trapping (98.6%) and a Fenton catalytic bottom layer for in situ pollutant degradation (98.1%) are constructed. Benzophenone-terminated polydimethylsiloxane is designed to realize facile asymmetric photo-grafting on porous paper, which further endows the evaporator with controlled Janus wettability, stable self-floating performance, long-term salt resistance, efficient heat management and rapid water transfer. Benefiting from such advantages, high solar-to-vapor efficiency (95.3%) and evaporation rate (1.88 kg m−2 h−1) are obtained. This cellulose paper-based evaporator also exhibits mechanical flexibility, portability and cost-effectiveness. Furthermore, the preparation process, including simple deposition and cleaner photo-grafting, is feasible and scalable for industrial production. This work provides innovative concepts for developing advanced paper evaporators to realize multitasking solar desalination. [ABSTRACT FROM AUTHOR]

Even in the age of electronic information, paper has always played an important role in most fields. Conventional cellulose-based paper is highly porous, rough, hydrophilic and possesses a single function. In this review, the development and challenges of cellulose-based paper are illustrated. In this case, inorganic paper can be regarded as the candidate material for the paper-making field. This review aims to summarize the most recent progress on inorganic paper. Significantly, different kinds of inorganic raw materials for designing inorganic paper will be presented, followed by a summary of their emerging applications. The raw materials can be divided into four parts: hydroxyapatite-based, silicon-based, carbon-based, as well as metal–organic framework-based materials. The inorganic paper produced by these raw materials has many applications, such as fire-resistance, pollutant treatment, actuator, flexible electronics and energy storage. The development of inorganic paper may provide new inspiration for the paper-making field. [ABSTRACT FROM AUTHOR]

In recent years, the development of multi-functional supercapacitors with high flexibility and strong environmental adaptability has gradually become a focus of attention. In this work, a multi-functional paper-based supercapacitor with excellent temperature adaptability, plasticity, tensile strength, strong adhesion, and self-healing properties is obtained by introducing PVA and ZnCl2 into carbonized paper-based materials (APC-PVA@ZnCl2). The as-obtained APC-PVA@ZnCl2 supercapacitor has excellent adaptability to the environment, even in a low-temperature environment below zero, still maintaining a high volumetric specific capacitance of 3438.45 mF cm−3 and high volumetric specific energy density of 44 mW h cm−3. Moreover, the APC-PVA@ZnCl2 supercapacitor can be stretched beyond 2400–2500% strain, indicating good tensile properties. In addition, the APC-PVA@ZnCl2 composite can also be used as a sensing material to detect current signals with different characteristics generated by the movement of different parts of the human body, showing excellent sensing performance. Besides, the APC-PVA@ZnCl2 composite also displays outstanding thermoelectric properties. It is hoped that this work can provide a reference for the development of green multi-functional supercapacitors. [ABSTRACT FROM AUTHOR]

With the rapid development of wearable electronic devices, multifunctional ultrarobust, thermoconductive, nonflammable, and electromagnetic interference (EMI) shielding films which are widely utilized to efficiently dissipate heat generated from electronic components are in high demand. The poor scalability and mechanical flexibility of multifunctional papers usually hinder their practical application. In this study, mass-scalable ultrarobust graphene nanoplatelet (GnP) cross-linked aramid nanofiber (ANF) papers with a nacre-bioinspired structure are fabricated via an evaporation-induced self-assembly approach. By chemical cross-linking between two-dimensional GnPs and one-dimensional ANFs in the nacre-bioinspired structure by a phosphorus agent, the excellent toughness and folding endurance of the GnP based ANF papers have been successfully achieved with simultaneous integration of high-level multifunctional properties. Specifically, the ultrarobust GnP based ANF paper with 50 wt% GnP loading exhibits exceptional ultimate tensile strength (437 MPa), Young's modulus (19.7 GPa) and toughness (23.9 MJ m−3) as well as superb folding endurance after 10 000 bending cycles. Moreover, the highly ordered alignment of GnP induced an unprecedented thermal/electrical conductivity, and the GnP (50 wt%) based ANF papers with an ultrathin thickness of 21 μm show a superb in-plane thermal conductivity (up to 68.2 W m−1 K−1) and outstanding absolute effectiveness EMI shielding (up to 11 060 dB cm2 g−1) and are comparable with some commercial metals/alloys. These outstanding mechanical flexibility integrated superb thermal/EMI properties along with mass-scale production pave the way for practical applications of GnP based ANF papers in the development of advanced thermal management materials in autonomous cars, air vehicles and wearable devices. [ABSTRACT FROM AUTHOR]

Composites with high thermal conductivity and excellent electromagnetic interference (EMI) shielding performance are in urgent demand in the fields of wireless communication technologies and portable intelligent electronic devices. However, it remains a great challenge to simultaneously improve thermal conductivity and EMI shielding effectiveness (SE) for polymer composites. This work reports a feasible and scaled method relating to vacuum-assisted filtration and compression-molding to fabricate nylon/graphene nanoplatelet (GNP) composite papers using commercial nylon gauze and GNPs. The results show that the composite papers exhibit good flexibility and multifunctional performances. At 11.8 wt% GNPs, the three-layered composite nylon/GNP paper, which had a thickness of about 180 μm, showed high thermal and electrical conductivities of 15.8 W m−1 K−1 and 24.3 S cm−1, respectively, and an outstanding EMI SE of 58.1 dB at the X-band (8.2–12.4 GHz). The compromise of thermal conductivity and EMI SE of the composite paper is much greater than that of other multifunctional composites reported in the literature. Specifically, the composite papers also show greatly enhanced hydrophobicity and flame resistance and satisfactory mechanical properties. To sum up, this work paves the way for the real engineering application of nylon-based composite papers in next-generation electronic devices. [ABSTRACT FROM AUTHOR]

This work reports a flexible yet robust Ti3C2Tx MXene/bamboo microfibril (BF) composite paper via a simple vacuum filtration process. Due to the excellent compatibility between MXene and BF, the MXene/BF composite paper demonstrates simultaneously an excellent tensile strength of 49.5 MPa, higher than that of both MXene sheet and BF film alone and also among the top values compared with those in the literature, an excellent electrical conductivity as high as 4.8 × 103 S m−1 which is also higher even at a lower MXene content than those reported in the literature, and outstanding electrical stability with no detectable deterioration after 1000 cycles of stretching, bending and compression. As a result, the MXene/BF composite paper shows versatility for making various high-performance wearable electronics. Specifically, the as-prepared flexible pressure sensor by stacking exhibits a high sensitivity of 0.153 kPa−1 and a linear sensing performance in the pressure range of 0 to 2.5 kPa; the as-fabricated electric heater displays outstanding electrothermal performance, giving a temperature difference of 20 °C in air at the lowest input voltage of 2.5 V compared with those of the literature; the produced wearable symmetric all-solid-state supercapacitor achieves large enhancements in volumetric capacitance and gravimetric capacitance compared with the neat MXene supercapacitor and outstanding energy storage stability upon varied deformations. The MXene/BF composite paper with the above virtues is appealing for wide applications in multifunctional wearable electronics. [ABSTRACT FROM AUTHOR]

The mechanical properties of thermally conductive composites are the key to realize their applications. Strength of materials is of significance, furthermore the toughness of materials also should attract more concern. Actually, few researchers have reported the simultaneous improvement of strength and toughness of anisotropic thermally and electrically conductive composites. Therefore, this study aims to obviously improve the in-plane thermal and electrical conductivities of nylon composites, which display superior tensile strength and toughness, compared to other thermally conductive composites. The nylon composite papers, prepared through a facile method involving vacuum-assisted filtration and compression molding processes, present a laminate structure and compact graphene nanoplatelet (GNP) stacks inside composites. On account of the special structure, the nylon composite papers show a super-high in-plane thermal conductivity of 16.0 W m−1 K−1 and electrical conductivity of 18.0 S cm−1 at a filler loading of 14.6 wt%. Surprisingly, the composite papers still exhibit a high strength of 48.3 MPa, which is comparable to that of a pure nylon film. In addition, the elongation at break of the composite paper with 14.6 wt% GNPs is as high as 34.2%, ultimately endowing the composite papers with a good toughness of 13.15 MJ m−3. The nylon composite papers successfully achieve the integration of excellent thermal and electrical conductivities, and superior strength and toughness, showing huge application values in the field of intelligent electronic device. [ABSTRACT FROM AUTHOR]

A flexible composite paper is designed by imitation of the conch shell structure, comprising graphene (RGO) and a two-dimensional transition metal (Ti3C2, MXene) as a cuticle layer, and cellulose nanofibrils (CNFs) as the nacre layer. The multi-component interconnected structure provided the RGO/CNFs/Ti3C2 composite with high conductivity and specific capacitance, as well as stable stimulus-response capability, enabling efficient modulation of interface performance or electronic/ionic transfer under complex environmental stimulations and creating interrelated functioning responses. The RGO/CNFs/MXene composite paper shows an excellent response to pressure, temperature and light. Besides, the fabricated flexible micro-supercapacitor (MSC) exhibits a total volumetric capacitance of 148.25 F cm−3 (vs. the whole device), excellent cycle stability, and volumetric energy density of 20.5 mW cm−3. Thus, the composite paper can act as both a multi-sensing unit to pressure/temperature/light and a flexible micro-supercapacitor (MSC) electrode to assemble a mechanically robust integrated device with a reliable stimulus response and moderate electrochemical capacitance to identify users and monitor vital signs by detecting different signal stimuli (motion, pulse, voice and signature), revealing its potential in human motion monitoring, and anti-counterfeiting recognition. This work demonstrates the feasibility of the use of a single functional material to fabricate multi-functional sensors, as well as high-performance supercapacitors, which provides a significant reference for new-generation portable intelligent integrated devices. [ABSTRACT FROM AUTHOR]

Power generation from renewable sources is important for sustainable development due to the depletion of traditional fossil fuels and related environmental pollution. In this work, paper is used to generate electricity under moisture ingress. As a result, a piece of untreated print paper (1.5 cm2 in area) can induce a voltage of 0.25 V and a current of 15 nA. The power output can be conveniently tuned by changing the humidity, temperature and number of devices by simple series/parallel connections. Such paper-based moist-electric generators (PMEGs) are expected to find their applications in the daily ambient environment owing to the wide availability and low cost of paper materials. A 'power' book is then fabricated to prove the concept, providing new insights into moist-electric power generation and a viable approach for designing extremely simple power generators for various applications. [ABSTRACT FROM AUTHOR]

Passive daytime radiative cooling (PDRC) is a promising energy-saving cooling method to cool objects without energy consumption. Although numerous PDRC materials and structures have been proposed to achieve sub-ambient temperatures, the technique faces unprecedented challenges brought on by complicated and expensive fabrication. Herein, inspired by traditional Chinese oil-paper umbrellas, we develop a self-cleaning and self-cooling oil-foam composite (OFC) made of recycled polystyrene foam and tung oil to simultaneously achieve efficient passive radiative cooling and enhanced thermal dissipation of objects. The OFCs show high solar reflectance (0.90) and high mid-infrared thermal emittance (0.89) during the atmospheric transparent window, contributing to a sub-ambient temperature drop of ∼5.4 °C and cooling power of 86 W m−2 under direct solar irradiance. Additionally, the worldwide market of recycled packaging plastics can provide low-cost raw materials, further eliminating the release of plastics into the environment. The OFC offers an energy-efficient, cost-effective and environmentally friendly candidate for building cooling applications and provides a value-added path for plastic recycling. [ABSTRACT FROM AUTHOR]

Highly foldable and flexible energy materials are a requisite for actual applications in self-powered wearable electronics and complex environments. Unfortunately, thermoelectric (TE) materials showing excellent foldability and flexibility under external mechanical stresses have rarely been reported so far. Herein, foldable and flexible TE materials based on Chinese traditional Xuan paper (a bio-based material) and commercialized conducting polymer of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) are reported. With a facile dip-coating and subsequent drying process, PEDOT:PSS is wrapped on the surfaces of cellulose fibers of Xuan paper via hydrogen-bond interactions. The resulting composite films exhibit outstanding mechanical and decent TE properties. In particular, the PEDOT:PSS/Xuan paper composite films exhibit excellent foldability and flexibility, and can be easily processed into various shapes with no distinct damage to their electrical conductivity and TE performances. This work paves the way for imparting TE performance to insulating paper-based materials, and the unique foldability may widen the TE applications in complex and extreme environments. [ABSTRACT FROM AUTHOR]

Large-scale and openly available material science databases are mainly composed of computer simulation results rather than experimental data. Some examples include the Materials Project, Open Quantum Materials Database, and Open Catalyst 2022. Unfortunately, building large-scale experimental databases remains challenging due to the difficulties in consolidating locally distributed datasets. In this work, focusing on the catalysis literature of CO2 reduction reactions (CO2RRs), we present a machine learning (ML)-based protocol for selecting highly relevant papers and extracting important experimental data. First, we report a document embedding method (Doc2Vec) for collecting papers of greatest relevance to the specific target domain, which yielded 3154 CO2RR-related papers from six publishers. Next, we developed named entity recognition (NER) models to extract twelve entities related to material names (catalyst, electrolyte, etc.) and catalytic performance (Faradaic efficiency, current density, etc.). Among several tested models, the MatBERT-based approach achieved the highest accuracy, with an average F1-score of 90.4% and an F1-score of 95.2% in a boundary relaxation evaluation scheme. The accurate and accelerated NER-based data extraction from a large volume of catalysis literature enables temporal trend analyses of the CO2RR catalysts, products, and performances, revealing the potentially effective material space in CO2RRs. While this work demonstrates the effectiveness of our ML-based text mining methods for specifically CO2RR literature, the methods and approach are applicable to and may be used to accelerate the development of other catalytic chemical reactions. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers (CNFs) and boron nitride nanotubes (BNNTs) are light-weight, eco-friendly and flexible materials with diverse chemical, physical, mechanical, piezoelectric and energy storage properties. In particular, their exceptional properties have been exploited in piezoelectric and supercapacitor applications. However, it is fairly challenging to enhance the supercapacitor and piezoelectric performances of ultrathin paper. Thus, a new strategy with a BNNT/CNF–inorganic ternary nanostructure is required in which the outstanding energy storage and conversion of inorganic materials simultaneously enhance the performance of supercapacitors and their piezoelectric properties. Herein, we have synthesized ZnO nanoparticles (NPs) on CNF and BNNT surfaces through cost-effective and facile hydrothermal method to give a ternary nanostructure and explored the electrochemical and piezoelectric performance. The BNNT–CNF/ZnO ternary nanostructure displays a remarkable specific capacitance of 300 F g−1 with high energy (37.5 W h kg−1) and power density (0.9 kW kg−1) at a current density of 1 A g−1. In terms of the flexibility of BNNT–CNF/ZnO, an ultra-thin flexible solid-state symmetric supercapacitor was fabricated, which demonstrated a high specific capacitance of 94 F g−1 under 1 A g−1 current density along with noticeable cycling stability (97% over 5000 cycles) and remarkable energy density (30.3 W h kg−1 at 1.3 kW kg−1). Furthermore, we examined the piezoelectric effect by employing a specific force on the BNNT–CNF/ZnO nanostructure flexible paper with different paper thicknesses. The BNNT–CNF/ZnO paper-based device presented an effective piezoelectric coefficient (d33) of −12.6 pC N−1 with 90 μm thick paper which is higher than that of the BNNT–CNF paper (−7.9 pC N−1). Therefore, this work will pave the way for the development of innovative next-generation flexible energy storage devices to generate recycled energy. [ABSTRACT FROM AUTHOR]

Multivalent Al metal anodes (AMAs) can deliver high specific/volumetric capacities (2980 mA h g−1/8046 mA h cm−3) in chloroaluminate ionic liquid-based electrolytes (ILEs). However, strong corrosion of their surfaces and poor charge transfer kinetics in acidic ILEs remain critical obstacles to realizing high-performance AMAs. In this study, a 3D-structured bifunctional MXene paper electrode (3D-BMPE), which has distinctive material properties, such as high electrical conductivity, high elastic modulus, a large number of nanopores, and multitudinous oxygen functional groups, was fabricated to protect Al deposition/dissolution reactions with improved redox kinetics. The 3D-BMPE obstructed Al corrosion during the long rest time in the ILE and consecutive cycling process, resulting in a significantly stable cycling performance of the 3D-BMPE-based AMA over 2000 cycles. Furthermore, Al nucleation and growth reactions were catalyzed in the nanoporous structure surrounded by the highly functionalized MXene surfaces, which reduced overpotentials by one-sixth, resulting in highly improved coulombic efficiencies of ∼99.9%. Moreover, the excellent electrochemical performance of the 3D-BMPE-based AMA was confirmed in Al-based dual-ion battery full cells, demonstrating the significant role played by 3D-BMPEs for AMAs. [ABSTRACT FROM AUTHOR]

On-chip energy units are urgently required for the rapid development of the Internet of Things and flexible electronics. Herein, a flexible integrated platform by incorporating paper microfluidic technology with a pencil-drawing approach is presented for self-charging/recharging, self-powered electropolymerization and sensing. By adopting a double bottom-up growth strategy based on paper microfluidics and a wax printing process, gold networks attached on intertwined cellulose fibers with extremely low horizontal sheet resistance (1.6 Ω sq−1) and good vertical conductivity (44.58 S cm−1) were achieved. Then, a low-cost pencil-drawing method based on the porosity of the paper substrate was introduced to overcome the key technical issue of reversible control for fluid and current. Utilizing the unique platform produced, a flexible power paper with a magnesium anode and a Prussian blue cathode was explored. The obtained output controllable power device was applied to drive the electropolymerization of polypyrrole film and a polyaniline network, and electrochemiluminescence images with competitive performance. It is believed that this work offers new insights into the formation of flexible green power and may be instructive for the future design of integrated platforms. [ABSTRACT FROM AUTHOR]

Herein, we report a new kind of highly flexible hydroxyapatite nanowire (HAPNW)-based layered catalytic paper with a high thermal stability, excellent fire resistance, and high catalytic efficiency for continuous flow catalysis. A simple process has been developed for preparing and loading gold nanoparticles (AuNPs) on the fire-resistant HAPNW paper to obtain the HAPNW/AuNP layered catalytic paper. Oleic acid molecules adsorbed on the surface of HAPNWs can effectively reduce Au(iii) ions to Au nanoparticles in situ in aqueous solution in the absence of an additional reducing reagent at room temperature. The size and weight percentage of AuNPs and surface hydrophilicity/hydrophobicity of the HAPNW/AuNP layered catalytic paper can be controlled. Benefiting from the nanoporous network and nanowire-based layered structure, the HAPNW/AuNP layered catalytic paper exhibits high catalytic activity for continuous flow reactions when the aqueous solution flows through the paper. Additionally, the HAPNW/AuNP layered catalytic paper can be easily recycled. Importantly, the HAPNW/AuNP layered catalytic paper shows excellent nonflammable properties and high catalytic stability after heat treatment. The HAPNW/AuNP layered catalytic paper has a high catalytic efficiency (100%), good recyclability, long-term stability, and high thermal stability in the continuous flow catalytic reduction of 4-nitrophenol. Furthermore, the catalytic degradation of organic dyes is also investigated. The HAPNW/AuNP layered catalytic paper is promising for applications in water treatment and high-temperature catalysis. In addition, the fire-resistant HAPNW-based paper can be used as an excellent support for various catalysts to prepare other kinds of catalytic paper for many applications. [ABSTRACT FROM AUTHOR]

Developing high-performance flexible film-like electrodes is still a primary task for the practical applications of wearable/portable planar supercapacitors. In this work, a facile and effective approach, i.e., stacking up layers of polyaniline (PANI)/carbon nanotube (CNT) composite networks inside air-laid papers, is proposed to fabricate highly flexible paper electrodes with large areal capacitance and superior rate capability. The layer-by-layer deposition of PANI/CNT networks endows the fabricated paper electrodes with high loading and uniform distribution of PANI; meanwhile, the good electrical conductivity and porous structure of these introduced PANI/CNT networks guarantee sufficient paths for electron movement and ion transportation in the electrodes. Consequently, when 4 layers of PANI/CNT networks (with optimal PANI content) are stacked inside papers, the areal capacitance of the prepared electrode is as high as 1506 mF cm−2 at a charge/discharge current of 10 mA cm−2 and 1298 mF cm−2 at 100 mA cm−2; the electrode also exhibits high flexibility and good cycling stability (with 82% capacitance retention after 11 500 charge/discharge cycles). These merits make our PANI/CNT/papers promising candidates for flexible planar supercapacitor electrodes. Besides, this work is believed to provide a new thought for producing high-loading and high-energy wearable/portable energy storage devices. [ABSTRACT FROM AUTHOR]

Wearable sweat biosensors, as the only noninvasive and measurable body-fluid sensors, serve as a very important means to monitor an individual's health status and more dynamic molecular-level information. The pursuit of wearable sweat biosensors includes not only detecting sweat components, but also integrating multiple functions, such as sweat-based health monitoring, near-field transmission and being self-powered. In this paper, we firstly bring forth a new idea of integrating sweat monitoring and dual electrical generation (hydrovoltaic and moisture electricity generation) for a multifunctional flexible device as a sweat-based health monitoring electronic (E)-skin. Herein, besides sweat composition analysis, a hydrovoltaic electricity generator is employed to detect the amount of sweat for the first time, and a dual electricity generator is used for self-supply of energy and skin-surface temperature measurement. Synergistic tandem nanogenerators are constructed using biomass carbon materials, and the power generation voltage can reach about 500 mV and is relatively stable. Our sweat E-skin (SE-skin) has five main functional areas, realizing real-time monitoring of sweat volume, sweat composition analysis skin-surface temperature measurement and power-supply functions. This new integrated design not only enables real-time monitoring of indicators of health in sweat, but also provides a new idea for future intelligent wearables for human beings. [ABSTRACT FROM AUTHOR]

Metal–organic framework (MOF)-derived transition metal chalcogenide (TMC) materials have been increasingly utilized owing to their superior electrocatalytic activity and durability. To prevent any limitations in the immobilization of nanocatalysts onto a working electrode substrate with binders, direct growth of MOF-derived TMC catalysts on a conductive substrate could be an improved fabrication strategy for realizing durable electrode systems. Herein, we report a facile method for growing cobalt-based zeolitic imidazolate framework-67 (ZIF-67) by using a cobalt hydroxide (Co(OH)2) layer electrodeposited on carbon paper (CP). Subsequently, ZIF-67 was used as a sacrificial template and converted into amorphous cobalt sulfide (CoxSy) to form CoxSy@Co(OH)2/CP by a post-treatment process (etching with thioacetamide). The final CP electrode incorporating the catalytic system (CoxSy@Co(OH)2/CP) exhibited remarkable oxygen evolution reaction (OER) performance with an overpotential of 180 mV at 10 mA cm−2 and stable activity after 24 h of continuous operation at a high current density of 50 mA cm−2. The excellent OER activity of the fabricated electrode system is attributed to the high surface area inherited from the MOF template, the robust structure of the catalytic system, the relatively large number of unsaturated surface sites of CoxSy, and the heterogeneous interface of amorphous CoxSy–crystalline Co(OH)2. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM) air pollution has been attracting much attention due to its great threat to human health. Herein, we report a new kind of air filter paper with high removal efficiencies for PM2.5 and PM10 prepared using ultralong hydroxyapatite (HAP) nanowires and cotton (CT) fibers as building blocks through a simple vacuum filtration process. Flexible and biocompatible ultralong HAP nanowires with lengths over 200 μm and diameters of approximately 20 nm are employed for significant improvement of the air filtration performance of commercial CT fibers. The ultralong HAP nanowires intertwine with CT fibers and form the highly porous HAP/CT air filter paper. In addition, by optimizing the proportion of HAP and CT, the as-prepared HAP/CT air filter paper exhibits high removal efficiencies of over 95% for PM2.5 and PM10; more importantly, it shows a lower pressure drop and a smaller thickness than a commercial breathing mask. Moreover, the fabrication of a large-sized HAP/CT air filter paper with desirable properties through a commercial sheet former is demonstrated. As a proof-of-concept, a homemade breathing mask is fabricated by imbedding the HAP/CT air filter paper into a commercial breathing mask. Furthermore, benefiting from the unique characteristics of ultralong HAP nanowires, other functions such as antibacterial activity can be achieved by the immobilization of silver nanoparticles as the representative bactericide, enabling the fabrication of multifunctional air filter paper. The experimental results suggest that the ultralong HAP nanowire-based air filter paper is promising for various applications in the environmental field. [ABSTRACT FROM AUTHOR]

Cellulosic materials are becoming more and more important in our daily life. However, if cellulose in its natural form such as paper is to be applied in advanced applications, it should exhibit unique characters in mechanical performance, barrier properties, etc. This paper describes a new method to design and fabricate a pure cellulosic composite with excellent mechanical and barrier properties via simple coating and cross-linking between original paper and regenerated cellulose. The cellulosic composite overcomes the shortcomings of the low mechanical and barrier performance of original paper. This material had an ultrahigh tensile strength, a high elongation and toughness at break of 76 MPa, 12% and 7 MJ m−1, and 13 MPa, 11% and 0.75 MJ m−3 under wet conditions, which were greater than those of original paper (dry: 20 MPa, 2.8%, 0.3 MJ m−3; wet: 1.08 MPa, 2.8%, 0.028 MJ m−3). Besides, the composite papers showed good barrier properties for small molecules such as polar molecules (H2O) and non-polar molecules (O2). Interestingly, the as-synthesized material exhibited shape-retention when the material was wetted with water. [ABSTRACT FROM AUTHOR]

Developing flexible microwave-absorbing film with efficient electromagnetic (EM) response and practicability is of great importance. However, it is still a big challenge for microwave-absorbing films to exhibit excellent EM response ability, good mechanical properties, and fine multifunctional features at the same time. Herein, novel microwave-absorbing papers (MAPs) are designed based on a facile poly(vinyl pyrrolidone)-assisted vacuum filtration assembly to take full advantage of the natural physical properties of carbon nanotubes and reduced graphene oxide. The constructed laminated papers not only keep the original performance characteristics of the conductive components, but also have new functionality by component integration and microscopic structure formation. Based on that, the minimum reflection loss value of MAPs is −49.6 dB at 1.5 mm and the effective absorption bandwidth reaches 6.2 GHz at 1.6 mm. Meanwhile, the optimum RCS reduction value reaches 17.5 dB m2 when the detection theta was set as 0°. Moreover, integrated functionalities are revealed in the MAPs, such as good flexibility, high tensile strength, light feature, having the nature of writing papers, machinability in architectures, and potential as thermal-protective coatings, demonstrating great potential for applications as microwave-absorbing devices or wearable smart electronics. [ABSTRACT FROM AUTHOR]

The surface of a negatively charged paper fiber was coated with quaternized chitosan (QCS) by electrostatic self-assembly to form a homogeneous positive coating due to the highly positive charge and excellent film-forming properties of QCS. Gold chloride acid acted as a precursor to prepare gold nanoparticles (AuNP) on a graphene oxide (GO) sheet. Then, this negatively charged AuNP-loaded graphene oxide sheet was directly absorbed by QCS on the surface of fibers via further electrostatic self-assembly in water. Finally, AuNP–reduced graphene oxide/QCS/cellulose composite paper (AuNP–rGO/QCS/cellulose) was fabricated by a papermaking process, following reduction by hydrogen iodide vapor. The XRD, Raman spectra, XPS and FE-SEM results of the composite papers showed that the electrostatic self-assembly caused the graphene oxide sheets to tightly wrap the paper fibers, and that the graphene oxide was reduced, thus being beneficial to the formation of a superior graphene conductive network. Notably, AuNP–rGO/QCS/cellulose composite paper possessed a conductivity of 853.4 S m−1, which is the highest among the reported conducted graphene-based cellulosic paper, to the best of our knowledge. Besides, this composite paper also presented an excellent performance in photothermal conversion and catalysis of nitrophenol reduction. This type of paper may have promising applications in electric devices, sensors and catalysts. [ABSTRACT FROM AUTHOR]

The ongoing surge in demand for flexible/wearable electronics spurs us to explore high-performance power sources with various form factors. Here we demonstrate monolithic heteronanomat (MH) paper air cathodes as a new electrode platform to enable the fabrication of origami-foldable zinc (Zn)–air batteries with reliable electrochemical rechargeability. The MH paper air cathodes consist of one-dimensional (1D) bifunctional catalyst mixtures (NdBa0.5Sr0.5Co1.5Fe0.5O5+δ double perovskite (NBSCF) nanofibers for the oxygen evolution reaction and nitrogen-doped carbon nanotubes (N-CNTs) for the oxygen reduction reaction), cellulose nanofibers (CNFs), and polytetrafluoroethylene (PTFE) nanoparticles, without the incorporation of conventional current collectors and gas diffusion layers. The CNFs and PTFE nanoparticles act as hydrophilic and hydrophobic binders, respectively, to construct three-dimensional (3D) bicontinuous electrolyte/air channels in the MH paper air cathodes. The well-developed electrolyte/air transport pathways, in combination with the rational design of the 1D bifunctional catalyst mixtures, enables the resultant Zn–air batteries (MH paper air cathode‖CNF separator membrane‖Zn–foil anode) to exhibit highly efficient charge/discharge performance and cyclability. In addition, the highly entangled network structure (based on a fibrous mixture of NBSCFs, N-CNTs, and CNFs) of the MH paper air cathode substantially improves its mechanical flexibility under various deformation modes, enabling the resultant Zn–air battery to be folded into a paper-airplane shape via origami folding. [ABSTRACT FROM AUTHOR]

A porous graphene paper was prepared by pressing a graphene cryogel, followed by thermal reduction at 220 °C. The cryogel was formed by freeze-drying a solution containing chemically reduced graphene and graphene oxide (CRG/GO). The formed graphene cryogel papers deliver a much higher discharge capacity and rate capability than that from conventional graphene papers fabricated by filtration. These new structures have a discharge capacity higher than 400 mA h g−1 at a current density of 2000 mA g−1 in sharp contrast to 229 mA h g−1 at 50 mA g−1 obtained from conventional graphene papers. These greatly improved electrochemical properties may be attributed to the porous structure and the concomitant high surface area. The mechanical properties may be tuned with the CRG/GO ratio. At a CRG/GO mass ratio of 2 : 1 the graphene paper has a Young's modulus nearly 9 times greater than an equivalent paper made from pure GO. [ABSTRACT FROM AUTHOR]

Being light, cheap, breathable and foldable, paper is emerging as a new type of substrate for flexible thermoelectric films. Several techniques including soaking and magnetron sputtering have been developed to coat inorganic semiconductors onto paper substrate, but the flexibility and thermoelectric performance of the resulting films are still far from satisfactory. This work implements a novel glass-fiber-aided cold-press method for achieving flexible n-type Ag2Te nanowire (NW) films on copy-paper substrate. A greatly enhanced electrical conductivity has been realized in Ag2Te NWs film due to the disappearance of grain boundaries under compression to 30 MPa. As a consequence, the largest power factor (PF) value of up to 192 μW (mK2)−1 at 195 °C surpasses the performance of paper based thermoelectric films reported previously. Moreover, the PF value only decreases by 20% after 500 bending cycles, suggesting the good flexibility of the copy-paper supported Ag2Te NWs films. A thermoelectric module containing 10 pieces of series-connected Ag2Te films is fabricated using this glass-fiber-aided cold-press method. With ΔT increasing from 20 K to 80 K, the open-circuit voltage of module continually increases from about 11 mV to 60 mV. This measurement of open-circuit voltage has been repeated 10 times to confirm the stability of paper-supported Ag2Te thermoelectric module. The glass-fiber-aided cold-press method in this study provides an effective access to high-performance, flexible and solvent-processable inorganic thermoelectric films on copy-paper substrate. [ABSTRACT FROM AUTHOR]

Composite nanocoating of cationic polyacrylamide and aqueous dispersion of hydroxyl-functionalized carbon nanotubes (CNTs) with pre-adsorbed alkali lignin on lignocellulose wood microfibers has been developed to produce lightweight, flexible, and electrically conductive paper sheets from a simple, low-cost, and well-established papermaking process. Electron microscopy and Fourier transform infrared spectroscopy revealed the formation of strong interfacial hydrogen bonding between the oxygen-containing functional groups on the CNT surfaces and the hydroxyl groups of the cellulose microfibers. As a result, the mechanical properties of the papers with CNT content as low as 2.5 wt% were greatly improved compared to the pristine materials, with up to 10, 55, and 422% increases in tensile strength, internal bonding strength, and wet strength retention, respectively. The multifunctional sensing behavior of the CNT–cellulose composite papers to tensile strain and liquid water was examined comprehensively. Results show that these papers have superior tensile strain sensitivity compared to conventional foil gauges. Moreover, the water-induced electrical resistance changes can be tailored by the paper composition and resistance variations of more than three orders of magnitude were achieved without any degradation of the sensing performance through cycling. These smart papers provide a low-cost and renewable alternative to petrochemical-based materials for portable electronics and sensing applications. [ABSTRACT FROM AUTHOR]

Introducing excellent capacitive materials and tailoring their combination modes with bacterial cells are promising steps to improve the integration degree and performance of supercapacitive paper-based microbial fuel cells (SC-PMFCs). Herein, through a layer-by-layer (LBL) strategy, in situ formed polypyrrole and bacterial cells were alternately constructed on carbon cloth for the anode of a SC-PMFC. The capacitive bioanode fabricated by three modifications of the polypyrrole/bacteria bilayer achieved the best performance due to the combined effects of bacterial loading amount, conductivity and metabolic activity loss during the whole LBL fabrication process. Benefiting from the functions of polypyrrole as both a capacitive material and a conductive intercalator between the bacterial layers, this bioanode exhibited improved electron transfer efficiency, enhanced power density and increased capacitance. Meanwhile, the polypyrrole layers in this capacitive bioanode can provide a protective effect to the bacterial layers, leading to superior performance-retention capacity during the storage period. This work creates an effective way to improve the integration level between MFC and supercapacitor technologies, which would push the development of SC-PMFCs and provide guidance to other biofuel cell-involved combination technologies. [ABSTRACT FROM AUTHOR]

A novel porous graphene paper is prepared via freeze drying a wet graphene oxide gel, followed by thermal and chemical reduction. The macroscopic structure of the formed graphene paper can be tuned by the water content in the gel precursor. With 92% water content, an interconnected macroporous network can be formed. This porous graphene (PG) paper exhibits excellent electrochemical properties. It can deliver a high discharge capacity of 420 mA h g−1 at a current density of 2000 mA g−1 when used as binder-free lithium ion battery anode. PG paper exhibits a specific capacitance of 137 F g−1 at 1 A g−1 in a flexible all-solid-state supercapacitor with PVA/H2SO4 electrolyte. It can maintain 94% of its capacitance under bending. This electrochemical performance and mechanical flexibility makes it an excellent material for flexible energy storage devices. [ABSTRACT FROM AUTHOR]

The document is a contents list for the Journal of Materials Chemistry A, which features reviews and papers on various topics related to materials for energy and sustainability. Some of the topics covered include metal-organic frameworks for purification, 3D-printed architectures for electromagnetic interference shields, and advancements in energy-efficient chlorine production. The journal aims to connect the world with the chemical sciences and reinvest profits into the chemistry community. The document is a compilation of research papers published in the Journal of Materials Chemistry A in 2024, covering proton conductors, photocatalytic hydrogen generation, supramolecular encapsulation, rechargeable batteries, and flame retardant materials. It also includes a retraction notice for a previously published paper. [Extracted from the article]

Exploitation and utilization of green energy are urgent for the sustainable development of human civilization. In this study, we report a series of novel moist-electric generators (MEGs) based on a polyhydroxyurethane (PHU) vitrimer for the first time. In sharp contrast to traditional polymer MEGs, vitrimer moist-electric generators (VMEGs) can provide high and sustained voltage outputs under high temperature and high moisture conditions without structural collapse and decomposition. Furthermore, after doping with Ti3C2, the resultant VMEG can simultaneously convert energy from both water and the sun to electrical energy, providing continuous power for electronic devices, such as timers, under a natural environment. It is noteworthy that the preparation of VMEGs can be easily scaled up by using PHU/cellulose paper composites. The resultant paper-based VMEGs exhibit high electrical output, while possessing excellent mechanical properties, good self-healing ability, and high flexibility and transparency. This study provides a novel strategy to fabricate advanced MEGs, and at the same time opens a novel application for vitrimer materials. [ABSTRACT FROM AUTHOR]

Although some progress has been made in flexible supercapacitors (SCs), their high energy density, mechanical robustness, and device-level editability and programmability are still highly desirable for the development of advanced portable and miniaturized electronics, especially considering the fact that these flexible devices are likely to experience some mechanical impact and potential damage. Herein, we demonstrate the fabrication of hybrid electrodes containing self-assembled 2D metal–organic framework (MOF)/reduced graphene oxide (rGO) papers, which not only efficiently alleviate the self-restacking of rGO and the MOF but also maintain high electrical conductivity (0.32 Ω cm), excellent flexibility and mechanical properties with a Young's modulus of 34.4 GPa and a tensile strength of 89.9 MPa. In addition, a one-for-two strategy is introduced to construct two types of porous electrodes for flexible asymmetric SCs via a one MOF-derived synthesis route with simply changing metal ion precursors. As a consequence, the flexible asymmetric SCs possess a high volumetric energy density of 1.87 mW h cm−3 and an outstanding volumetric power density of 250 mW cm−3. More importantly, the all-solid-state asymmetric SCs exhibit high editability and bending-tolerance properties and perform very well under various severe service conditions, such as being seriously cut, bent, and heavily loaded. Particularly, the operations of micro-SCs with artistically designed patterns are demonstrated. Being high-strength, easily programmable and connectable in series and in parallel, the editable supercapacitor is promising for developing stylish energy storage devices to power various portable, miniaturized, and wearable devices. [ABSTRACT FROM AUTHOR]

Paper-like free-standing germanium (Ge) and single-walled carbon nanotube (SWCNT) composite anodes were synthesized by the vacuum filtration of Ge/SWCNT composites, which were prepared by a facile aqueous-based method. The samples were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Electrochemical measurements demonstrate that the Ge/SWCNT composite paper anode with the weight percentage of 32% Ge delivered a specific discharge capacity of 417 mA h g-1 after 40 cycles at a current density of 25 mA g-1, 117% higher than the pure SWCNT paper anode. The SWCNTs not only function as a flexible mechanical support for strain release, but also provide excellent electrically conducting channels, while the nanosized Ge particles contribute to improving the discharge capacity of the paper anode. [ABSTRACT FROM AUTHOR]

As a promising solution for the next generation of flexible and disposable electronics, paper-based devices are being studied intensively. However, as one of the cores of paper-based devices, many reported supercapacitors (SCs) suffer from disadvantages such as cumbersome fabrication, complicated packaging, low power density etc. Here we demonstrate a facile and scalable method to fabricate paper-based SCs by an improved pencil drawing strategy. The multi-walled carbon nanotubes are directly assembled onto pencil graphite flakes to form controllable graphite/MWNT frameworks, which act as high-performance electrodes. These SCs can deliver a power density of up to 15.1 W cm−3 and cycle at a scan rate of up to 150 V s−1, which are among the highest values achieved for any paper-based SCs. To demonstrate their applicable power/energy densities, the SCs are applied in series to drive LED and wireless sensor systems based on Bluetooth technology. [ABSTRACT FROM AUTHOR]

We report a facile scale-up process to fabricate a novel type of hybrid paper electrode composed of reduced graphene oxide (RGO), polypyrrole (PPy) and cellulose. Through the optimization of preparation parameters (including the processes of in situ polymerization of pyrrole and chemical reduction of graphene oxide by using NaBH4), the fabricated hybrid paper had an extremely low sheet resistance of 1.7 Ω sq−1. Also, the hybrid paper possessed favorable mechanical flexibility and outstanding conductance stability. When the paper was evaluated as a free-standing and binder-free supercapacitor electrode, the unique construction (i.e., the cellulose fiber frame supporting interpenetrated RGO–PPy nanoacrhitectures) endowed it with high electrochemical activity, such as high areal capacitance of 1.20 F cm−2 at 2 mA cm−2 and good cycling stability with a capacitance retention of 89.5% after cycling 5000 times, which was tested in a three-electrode configuration. In addition, an all-solid-state laminated symmetric supercapacitor was prepared by assembling two pieces of hybrid paper electrodes and using a H3PO4/PVA gel as the electrolyte. The solid-state supercapacitor had a high areal capacitance of 0.51 F cm−2 at 0.1 mA cm−2 and a high energy density of 1.18 mW h cm−3. These results suggest that the hybrid paper is a promising electrode material and may be useful for the development of flexible high-performance and hand-held energy storage devices. More importantly, this work provides a good reference for the fabrication of other types of hybrid paper electrodes. [ABSTRACT FROM AUTHOR]

Porous MgO–CaO–SnOx nanocubes (crystalline SnOx and amorphous MgO/CaO) were synthesized to implant firmly and uniformly onto in situ formed carbon paper by a facile route including a template-free growth process and calcining treatment. Low-cost filter paper was used to realize the part implantation of cubes as well as a source of carbon paper. The mechanistic analysis demonstrates that Mg2+/Ca2+ ions and ammonium hydroxide played important roles in the formation of the cubic phase precursor. This MgO–CaO–SnOx-nanocubes/carbon paper could be directly applied as a binder-free film electrode for lithium-ion batteries eliminating conventional electrode fabrication processes, and an average capacity contribution of ~719 mA h g-1 for MgO–CaO–SnOx nanocubes through 40 cycles was achieved. The facile synthesis strategy combines the material synthesis, dispersion and electrode fabrication, which further opens a new avenue for the application of nano-architectures in energy storage. [ABSTRACT FROM AUTHOR]

Nowadays, serve threats to both the environment and human health are caused by toxic spills, ever-increasing dye-containing industrial wastewater and fine particulate matters (PMs). It is essential to remove contaminants before releasing them into the environment. Simultaneously, many materials that have been studied contaminant removal, such as membranes and fibres, have poor tolerance to a broad working temperature range, and their robustness are needs to be improved. In this study, the multifunctional inorganic paper containing hydroxyapatite (HAP), carboxymethyl inorganic paper (CMC) and NH2-UiO-66 was prepared by a facile and environment-friendly process for both air and liquid contaminant filtration. In addition, the inorganic paper exhibited underwater superoleophobicity that can be used for the efficient separation of surfactant-stabilized oil-in-water emulsions. [ABSTRACT FROM AUTHOR]

Graphene-based hybrids, specifically free-standing graphene-based hybrid papers, have recently attracted increasing attention in many communities for their great potential applications. As the most commonly used precursors for the preparation of graphene-based hybrids, electrically-insulating graphene oxides (GO) generally must be further chemically reduced or thermally annealed back to reduced GO (RGO) if high electrical conductivity is needed. However, various concerns are generated if the hybrid structures are sensitive to the treatments used to produce RGO. In this work, we develop a highly facile strategy to fabricate free-standing magnetic and conductive graphene-based hybrid papers. Electrically conductive graphene nanosheets (GNs) are used directly to grow Fe3O4 magnetic nanoparticles without additional chemical reduction or thermal annealing, thus completely avoiding the concerns in the utilisation of GO. The free-standing Fe3O4/GN papers are magnetic, electrically conductive and present sufficient magnetic shielding (＞20 dB), making them promising for applications in the conductive magnetically-controlled switches. The shielding results suggest that the Fe3O4/GN papers of very small thickness (＜0.3 mm) and light weight (∼0.78 g cm−3) exhibit comparable shielding effectiveness to polymeric graphene-based composites of much larger thickness. Fundamental mechanisms for shielding performance and associated opportunities are discussed. [ABSTRACT FROM AUTHOR]

Despite the high number of research articles regarding the development of new high performance electrolytes for Li-ion batteries, relatively little work has been carried out for the investigation of green, mechanically robust, safe and commercially applicable paper separators. In this work, newly elaborated paper separators made of natural cellulose fibres are prepared by filtration dewatering. Paper separators show high porosity, wettability and mechanical robustness along with remarkable ion transport characteristics. The novel approach is conceptually validated by constant current charge/discharge cycling in a lab-scale Li-ion all-paper “pouch” cell assembled with a four-layer handsheet stacking separator in combination with a graphite-based paper-anode and a LiFePO4-based paper-cathode. This unravels the possibility of implementing the newly elaborated paper separators in safe, green and cost effective energy storage devices especially as they are obtained by rapid, low-cost and eco-friendly water-based paper-making techniques. [ABSTRACT FROM AUTHOR]

The document is a contents list for the Journal of Materials Chemistry A, featuring articles and reviews on various topics such as energy and sustainability, sodium storage, pressure sensors, and green nanogenerators. The journal aims to support the chemistry community by reinvesting its profits. The papers cover a wide range of subjects, including passive cooling, solar-powered ammonia production, formaldehyde degradation, and oil spill removal, among others. Each paper offers unique insights and findings in their respective fields. [Extracted from the article]

The document is a contents list for the Journal of Materials Chemistry A, a publication by the Royal Society of Chemistry. The journal focuses on materials for energy and sustainability. The contents list includes various articles and papers on topics such as solar energy harvesting, catalytic graphitization of biomass-based materials, wearable flexible pressure sensors, and molecular sieving of hydrocarbons. The journal aims to provide a platform for research on materials that contribute to a sustainable and inclusive future. This document is a list of papers published in the journal "Journal of Materials Chemistry A" in 2024. The papers cover a range of topics related to materials chemistry, including hydrogen evolution, lithium-ion batteries, solid-state lithium metal batteries, and photocatalytic reactions. The document also includes corrections and a retraction of a previously published paper. [Extracted from the article]

Ensuring the stability of the electrode and electrolyte in Li–O2 batteries and achieving a comprehensive understanding of parasitic side reaction management during cycling are key issues for the progress of this promising energy storage technology. Conditions that favour formation of either Li2O2 or Li2CO3 in Li–O2 cells on carbon-based electrodes were investigated. Operando Raman microscopy measurements and ex situ Raman and X-ray photoelectron spectroscopy (XPS) analyses were performed for Li–O2 systems using Li[ClO4]/DMSO as the electrolyte and carbon paper (CP) and carbon paper with carbon nanotubes (CPCNT) as electrodes. Using CP electrodes (either treated or untreated with O2 plasma), the major discharge product formed was Li2O2. In contrast, for CPCNT electrodes, the formation of Li2CO3 as the main discharge product was observed at lower capacities, then significant formation of Li2O2 proceeded at higher discharge capacities. XPS highlighted that the surface chemistry of the CPCNT electrode comprised fluorine and a variety of iron species, which could be linked to the promotion of Li2CO3 formation. Furthermore, it was observed that when Li2CO3 is the main discharge product, the active sites of functional groups on carbon surfaces that favour carbonate formation become coated/passivated. Consequently, the dominant reaction pathway then alters, leading to the growth of Li2O2 over the surface. These outcomes emphasized the important role in cycling stability of the active sites on carbon electrodes, arising from the synthesis process or possible contaminants. [ABSTRACT FROM AUTHOR]

Porous binder-free carbon electrodes were obtained by impregnating cellulose filter papers with phenolic resin through soft-salt template synthesis and thermal pyrolysis. These self-standing electrodes were used directly in a supercapacitor device. To understand the impacts of filter paper (FP) thickness on carbon filter paper (CFP) morphology, porosity, and surface functionalities, five different materials were examined. The CFP electrode thickness was adjusted linearly with the FP thickness to produce electrodes ranging from 100 to ∼800 μm. As the thickness of the CFP increased, there was an increase in the specific surface area and oxygen-based functionalities. Electrochemical testing in a 1 M KOH aqueous electrolyte demonstrated that electrode thickness played a key role in electrochemical capacitor (EC) performance, i.e., capacitance enhances linearly when the electrode becomes thinner. For low thicknesses (<280 μm), the capacitance and rate capability decreased slightly with increasing thickness; for high thicknesses, the performance drastically degraded despite the high specific surface area and oxygen surface functionalities. This effect was amplified at high regimes, indicating that high electrode thicknesses and fiber diameters limited electrolyte diffusion in the applied synthesis conditions. Thus, the high material porosity was inaccessible to ion adsorption. Consequently, thinner electrodes showed the highest capacitance (197 F g−1 at 0.1 A g−1) and rate capability (81%) values, exceeding those of their traditional binder-electrode counterparts prepared under similar conditions. Finally, for alkali metal hydroxide solutions, 1 M KOH exhibited a cation match with the salt template (KCl), while CsOH achieved additional capacitance retention (88% at 10 A g−1). Complex ion adsorption mechanisms were observed through a quartz crystal microbalance. [ABSTRACT FROM AUTHOR]