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Carbon paper is commonly used for catalytic electrode preparation because of its high conductivity, corrosion resistance, and stability. However, traditional electrode preparation methods are inappropriate for highly hydrophobic carbon paper. In this paper, a high‐activity carbon paper catalytic electrode was prepared using multistrategies cold plasma modification to create atomic structural defects, dope N and Cu elements, and introduce oxygen‐containing functional groups. Analyses show that the bombardment of high‐energy particles caused atomic structural defects. Nitrogen and copper entered the carbon paper through plasma‐induced chemical recombination and physical adsorption, reaching 5.26% and 3.83%, respectively. Ethanol‐based plasma introduced oxygen‐containing functional groups to improve hydrophilicity. Finally, the plasma‐prepared electrode exhibited a reduction efficiency of 87.69% in an electrocatalytic nitrate reduction reaction. [ABSTRACT FROM AUTHOR]

Traditionally, cellulose nanofiber (CNF) production has primarily relied on virgin cellulose sources. Yet, the shift to using paper mill sludge (PMS) as a source for CNF underscores the significance of reusing and recycling industrial byproducts. PMS contains significant amounts of cellulose that can be extracted as a raw material. The purpose of present study is to provide a sustainable approach to PMS utilization as a paper coating additive in the cellulose nanofibrils (CNFPMS) form via simply scalable wire-wound rod coating method. The effect of CNFPMS additive amounts at two coating layers on microstructure and surface properties of coatings such as porosity, air permeability surface roughness and optical properties such as brightness, gloss and CIE L*a*b* is studied, which they can also provide insight for the eventual print performance. Results indicated that the obtained CNFPMS in paper coating shows 52% decrease in porosity, presenting significant improvement in the coating microstructure. The marginal increase in permeability coefficient and surface roughness, 54% and 10%, respectively, suggests improving color reproduction and preventing color density losses. Optical analysis showed slight decrease in brightness and gloss, as was expected. Notably, the lightness was improved, which also indicates increasing color gamut volume in printing applications. As a result, the current work offers a sustainable approach to manage PMS for use in paper coatings as a high-value-added material. [ABSTRACT FROM AUTHOR]

Printed electronic paper identifies its interest in flexible organic electronics and sustainable and clean energy applications because of its straightforward production method, cost‐effectiveness, and positive environmental impact. However, current limitations include restricted material thickness and the use of supporting substrate for printing. Here, 2D and 3D electronic patterned paper are fabricated from direct ink writing (DIW) nanocellulose and PEDOT:PSS‐based materials using syringe deposition and 3D printing. The conductor patterns are integrated in the bulk of the paper, while non‐conductive sections are used as support to form free‐standing paper. The strong interface between the patterns of electronic patterned paper gives mechanical stability for practical handling. The conductive paper‐based electrode has 202 S cm−1 and is capable of handling electric current up to 0.7 A, which can be used for high‐power devices. Printed supercapacitor papers show high specific energy of 4.05 Wh kg−1, specific power of 4615 W kg−1 at 0.06 A g−1, and capacitance retention above 95% after 2000 cycles. The new design structure of electronic patterned papers presents a solution for additive manufacturing of paper‐based composites for supercapacitors, wearable electronics, or sensors for smart packaging. [ABSTRACT FROM AUTHOR]

The suitability of Eucalyptus grandis bark and root for the pulp and paper industry was investigated. The bark of E. grandis was cooked using sodium borohydride (NaBH4) in the kraft process, while the root of E. grandis was cooked using the soda-anthraquinone (AQ) process. Four different charges (0.0, 0.3, 0.5, 0.7%) of NaBH4 and AQ used as catalysts were added to the cooking liquor used in the processes. The chemical, mechanical and optical properties of the produced pulps were investigated and characterized. The yields, viscosity values, kappa numbers, as well as the brightness, tensile, burst and tear indices of the pulps were determined. The yield (RP: 39.1%, BP: 36.8%), viscosity value (RP: 897 cm3/g, BP: 650 cm3/g) and the kappa numbers (RP: 90, BP: 50) of the pulps produced from the root (RP) were higher than those of the pulps produced from bark (BP). The catalysts generally affected all the pulp properties, improving the properties of BP and RP. It was concluded that E. grandis bark and root can be suitable for the pulp and paper industry. [ABSTRACT FROM AUTHOR]

We developed an integrated gas diffusion layer (GDL) for proton exchange membrane (PEM) fuel cells by growing carbon nanofibers (CNFs) in situ on carbon paper via the electro-polymerization of polyaniline (PANI) on carbon paper followed by a subsequent carbonization treatment process. The CNF/carbon paper showed a microporous structure and a significantly increased pore volume compared to commercial carbon paper. By utilizing this CNF/carbon paper in a PEM fuel cell, it was found that the cell with CNF/carbon paper had superior performance compared to the commercial GDL at both high and low humidity conditions, and its power density was as high as 1.21 W cm−2 at 100% relative humidity, which is 26% higher than that of a conventional gas diffusion layer (0.9 W cm−2). The significant performance enhancement was attributed to a higher pore volume and porosity of the CNF/carbon paper, which improved gas diffusion in the GDL. In addition, the superior performance of the cell with CNF/carbon paper at low relative humidity demonstrated that it had better water retention than the commercial GDL. This study provides a novel and facile method for the surface modification of GDLs to improve the performance of PEM fuel cells. The CNF/carbon paper with a microporous structure has suitable hydrophobicity and lower through-plane resistance, which makes it promising as an advanced substrate for GDLs in fuel cell applications. [ABSTRACT FROM AUTHOR]

• Preparation of ZIF-67/PEDOT/CP self-supporting electrodes using simple in situ hydrothermal. • The addition of PEDOT to ZIF-67 helps to achieve high electrical conductivity and large specific surface area. • The sensor has a high detection performance for CGA. • ZIF-67/PEDOT/CP provided a new sensor for the detection of CGA in real sample. The design of efficient electrocatalysts for the determination of chlorogenic acids (CGA) is crucial in the biological and medical fields. In this paper, ZIF-67/poly(3,4-ethylenedioxythiophene) (PEDOT) nanocomposites were synthesised. The introduction of PEDOT increased the electrical conductivity of the ZIF-67/PEDOT composites, inhibited the Co atom agglomeration, led to the exposure of more active sites and increased the transport channels. An ultrasensitive CGA sensor based on ZIF-67/PEDOT nanocomposite modified carbon paper (CP) electrode was developed. The nanomaterials were characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to study the electrochemical properties of the modified CP electrode. In addition, the effects of different experimental conditions such as pH, scan rate and concentration on the peak current of CGA were investigated. Under the optimised conditions, the linear range of ZIF-67/PEDOT/CP for the determination of CGA was 0.1 ∼ 40 μM, and the limit of detection (LOD) was as low as 0.003 μM (S/N = 3). Furthermore, the sensor was successfully used for the quantitative analysis of CGA in real samples. [ABSTRACT FROM AUTHOR]

MXene is a promising energy storage material for miniaturized microbatteries and microsupercapacitors (MSCs). Despite its superior electrochemical performance, only a few studies have reported MXene‐based ultrahigh‐rate (>1000 mV s−1) on‐paper MSCs, mainly due to the reduced electrical conductance of MXene films deposited on paper. Herein, ultrahigh‐rate metal‐free on‐paper MSCs based on heterogeneous MXene/poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS)‐stack electrodes are fabricated through the combination of direct ink writing and femtosecond laser scribing. With a footprint area of only 20 mm2, the on‐paper MSCs exhibit excellent high‐rate capacitive behavior with an areal capacitance of 5.7 mF cm−2 and long cycle life (>95% capacitance retention after 10,000 cycles) at a high scan rate of 1000 mV s−1, outperforming most of the present on‐paper MSCs. Furthermore, the heterogeneous MXene/PEDOT:PSS electrodes can interconnect individual MSCs into metal‐free on‐paper MSC arrays, which can also be simultaneously charged/discharged at 1000 mV s−1, showing scalable capacitive performance. The heterogeneous MXene/PEDOT:PSS stacks are a promising electrode structure for on‐paper MSCs to serve as ultrafast miniaturized energy storage components for emerging paper electronics. [ABSTRACT FROM AUTHOR]

Stimuli-responsive phosphorescence materials with dynamic color-changing properties are highly promising for advanced information security. Herein, we demonstrate a novel strategy that effectively induces tunable dynamic phosphorescence color from carbon dots (CDs) on papers via surface ionization engineering for multimode encryption and information storage. Alkali-induced phenolic hydroxyl ionization on CDs can boost intersystem crossing rates, while surface-ionized groups with negative charges significantly passivate the surface defects and reduce non-radiative transitions, which can activate surface state-related blue phosphorescence emission. Combined with the carbon core state-related yellow-green phosphorescence, excitation/time-dependent phosphorescence color-changing from yellow-green to blue are realized from alkali (Na 2 CO 3) treated CDs on paper. Furthermore, benefiting from the transition from NaHCO 3 to Na 2 CO 3 under thermal treatment, dynamic color-changing phosphorescence can also be activated by thermally stimulating NaHCO 3 -treated CDs on paper. Finally, multi-stimuli (alkali or thermal) and multi-modal dynamic phosphorescent colors from a single CDs system are realized for the first time. Based on these unique features, multimode encryption and smart 3D codes with anti-counterfeiting and monitoring functions for medicine during transport or storage are demonstrated by combining an inkjet printing technique using CD inks. Multistimuli and excitation-dependent dynamic phosphorescence colors from a single CD system were realized for the first time for dynamic multimode encryption. Dynamic phosphorescence colors can be modulated from the dual phosphorescent centers of CDs in the surface triplet state and the carbon core-related triplet state, where the surface triplet state can be activated by external stimuli (alkali or thermal). [Display omitted] • A new surface ionization-activated RTP from CDs surface state strategy is proposed. • Multistimuli- and excitation/time-dependent RTP color variations from single CDs system are realized for the first time. • Smart 3D codes with monitoring function for medicine are developed for the first time. [ABSTRACT FROM AUTHOR]

Paper and paper board are an ideal choice of packaging material due to their biodegradability. They are safer than commonly used plastic packaging materials. But due to the presence of carbon sources like cellulose and starch in paper, various pathogenic and non‐pathogenic microbes can grow well in them. The migration of microorganisms or their spores from paper to food may cause serious health hazards. Taking consumer concerns into picture, the regulatory authorities should come up for food packaging standards with regard to microbial limits of paper used in food packaging. This study pinpoints the correct approach, that is, the disintegration method in comparison to direct plating in evaluating the microbial load of 14 different samples of paper by demonstrating the limitations of methods that were eliminated. The samples were also tested for storage effect on microbial load and found to have significant reduction in bacterial load during storage at 4°C, but for fungi, it remained nearly unchanged. Further identification of predominating microbes was performed, and conclusions have been drawn on the presence of harmful and harmless species in the samples of paper. It was found that all the identified fungi are mycotoxin producing and may lead to illness of the consumer. Unlike fungi, dominating bacterial strains were found to be non‐harmful for food packaging purposes and ultimately for human use. Overall, there is an immediate need to set microbial limit standards in food packaging paper and paperboard in order to supply safe and hygiene food to consumers. [ABSTRACT FROM AUTHOR]

The text provides a summary of various articles related to air quality, climate change, and environmental initiatives. It mentions a report from the World Meteorological Organization (WMO) highlighting record-breaking climate change indicators in 2023, the use of pulp and paper waste to reduce carbon emissions, the development of national indoor quality standards for public buildings, the establishment of a hydrogen hub in the Pilbara region of Australia, and the U.S. Environmental Protection Agency's new tailpipe rules to reduce pollution from cars and light trucks. These articles offer insights into the current state of the environment and efforts to address climate change. [Extracted from the article]

[Display omitted] • Facile and scalable self-assembly of perylene diimide polymer with carbon paper. • Effective facilitation of carrier separation by π-π built-in electric field. • Narrowed band gap and low VB due to the VB tail states induced by π-π interactions. • Enhanced photocatalytic water oxidation activity of the PDIP/CP photocatalyst sheet. • Suitability of the PDIP/CP photocatalyst sheet for large-scale applications. Photocatalytic water splitting is a highly promising future energy technology. In contrast to the extensive work on particulate photocatalysts, there is still a lack of sufficient investigation for regularized photocatalysts. Here, from perylene diimide polymer (PDIP) and commercial carbon paper (CP), we develop a self-assembled PDIP/CP photocatalyst sheet that is easily scalable and can be used for photocatalytic water oxidation. Driven by strong interfacial π-π interactions, the PDIP spontaneously adsorbs onto the CP, which leads to a narrowed band gap, down-shifted VB edge, and enhanced separation of the photogenerated charge carriers of the PDIP. Under visible light, the PDIP/CP photocatalyst sheet shows significantly enhanced photocatalytic water oxidation activity (4 h cumulative oxygen evolution is 1.7 times higher than that of the powder-suspended system) and considerable cycling stability. The PDIP/CP photocatalyst sheet has the potential for large-scale device applications. [ABSTRACT FROM AUTHOR]

Developing efficient and stable non-noble metal oxygen evolution reaction (OER) electrocatalysts for sustainable overall water-splitting is extremely desirable but still a great challenge. Herein, we developed a facile strategy to fabricate Co 3 O 4 –CoOOH heterostructure nanosheet arrays with oxygen vacancies grown on carbon paper (Co 3 O 4 –CoOOH/CP). Benefiting from the unique 3D architecture, large surface area, synergistic effects between Co 3 O 4 , CoOOH and oxygen vacancies, the obtained self-supporting Co 3 O 4 –CoOOH/CP presents excellent electrocatalytic OER activity (low overpotentials of 245 and 390 mV at 10 and 100 mA cm−2) and robust long-term stability in alkaline condition. The present strategy provides the opportunities for the future rational design and discovery of high-performance non-noble metal based electrocatalysts for advanced water oxidation and beyond. [Display omitted] • Co 3 O 4 –CoOOH heterostructure with oxygen vacancies grown on carbon paper was synthesized. • Synergic effect between oxygen vacancies and Co 3 O 4 –CoOOH facilitates the activity. • The Co 3 O 4 –CoOOH/CP exhibited excellent activity and stability for OER. [ABSTRACT FROM AUTHOR]

The paper industry is a high-carbon emission and energy-intensive industry. From the perspective of low-carbon trade and carbon neutrality, its energy conservation and emission reduction are worthy of attention. This study used the input-output model to calculate the embodied carbon emissions of China’s paper industry’s export trade to the United States from 2006 to 2020 and used the logarithmic mean division index (LMDI) method to analyze influencing factors of the change of embodied carbon emissions. The study found that the embodied carbon emissions of China’s paper industry’s export trade to the United States generally shows a stable downward trend after reaching the peak with the increase of export trade scale; scale effect is the main factor that causes the embodied carbon emissions, while technological progress, policy support, and environmental regulations are important driving forces to promote carbon emission reduction. The research results of this paper not only can test and guide China’s paper industry trade policies and industrial policies, but they can also provide decision-making reference for China and the United States to promote the carbon emission reduction of the paper industry. [ABSTRACT FROM AUTHOR]

• A technology-rich system model is created by integrating operations at MRFs and recycling paper mills. • Our model assesses sustainable pathways for U.S. domestic paper recycling industry. • Domestic recycling rate can increase by 15 % with better collection rate and sorting efficiency. • Use of recycled fibers can reduce energy and carbon intensities for most paper products. Dramatic changes in global recovered paper markets, triggered in large part by Chinese import restrictions, challenge the U.S. to find sustainable pathways for increasing the domestic paper recycling rate. This study presents a technology-rich process model of the U.S. domestic paper recycling industry to assess the energy consumption, carbon emissions, and system costs. A scenario analysis shows the viability of three potential pathways for achieving the national goals of a 15 % increase in both the paper recycling rate and the recycled paper utilization rate. The results suggest that the national goals can be achieved by recovering 80 % of recyclable papers from households and commercial stores, while trading all exported bales to domestic recovery with additional investments in processing capacity expansion. The deployment of advanced technology can enable material recovery facilities (MRFs) and paper mills to produce most recycled paper products that are more energy efficient with fewer CO 2 emissions. [ABSTRACT FROM AUTHOR]

This paper studies the impact of digital economy development on carbon emissions, which is a hot topic in the field of environmental economics. This topic is within the scope of the Frontiers in Environmental Science and is particularly in line with the theme of Environmental Economics and Management section in the journal. Firstly, this paper constructs the Digital Economy Development Index and its variable indicators to measure the development of the digital economy. Secondly, this paper uses urban panel data to reveal the impact of digital economy development on carbon emissions, and further adopts IV method to deal with endogeneity issues. Thirdly, this paper performs the heterogeneity analyses depending on the characteristics of the city. The results can provide a basis for formulating differentiated policies. Fourthly, this paper further explores the mechanism by which the digital economy affects carbon peaking. The results show that the digital economy may influence carbon peaking through upgrading of the industrial structure, technical innovation, and energy consumption. [ABSTRACT FROM AUTHOR]

The cost-effective implementation of nanofibrillated cellulose (CNF) at industrial scale requires optimizing the quality of the nanofibers according to their final application. Therefore, a portfolio of CNFs with different qualities is necessary, as well as further knowledge about how to obtain each of the main qualities. This paper presents the influence of various production techniques on the morphological characteristics and properties of CNFs produced from a mixture of recycled fibers. Five different pretreatments have been investigated: a mechanical pretreatment (PFI refining), two enzymatic hydrolysis strategies, and TEMPO-mediated oxidation under two different NaClO concentrations. For each pretreatment, five high-pressure homogenization (HPH) conditions have been considered. Our results show that the pretreatment determines the yield and the potential of HPH to enhance fibrillation and, therefore, the final CNF properties. These results enable one to select the most effective production method with the highest yield of produced CNFs from recovered paper for the desired CNF quality in diverse applications. [ABSTRACT FROM AUTHOR]

This document is a summary of a special issue in the journal Applied Sciences titled "Feature of Review Papers in Nanotechnology and Applied Nanosciences." The special issue aims to gather review papers that highlight recent developments and applications in the field of nanosciences. The seven contributions in this special issue cover a range of topics, including the use of nanocellulose for cultural heritage preservation, protective coatings for metal-based bipolar plates in water electrolysis, carbon dioxide electrocatalytic reduction reactions using transition metal sulfide nanomaterials, plasmonic techniques for detecting micro- and nano-plastics, graphene-based perfect absorbers, nano titanium dioxide for hydrogen production and storage, and X-ray spectroscopy studies of metal-salen complexes. The special issue provides a sample of the diverse applications of nanotechnology and addresses important issues in our polluted and climate-degraded world. [Extracted from the article]

Wearable electronic energy storage devices usually require the integration of flexible mechanisms and uncompromising electrochemistry of lithium-ion batteries (LIBs). Most of the studies in this field have mainly focused on enhancing the electrochemical properties of the material, while the significance of its flexibility and mechanical properties has been relatively ignored. In this study, the 20 wt % carbon fibers (CFs) composite N-doped flexible carbon nanofiber paper (NFCFP) was prepared through a facile PFI refiner and Bauer sieve of pulping and papermaking machinery sieve-assisted methods combined with annealing technology. The NFCFP-700 with high pyridine N content shows good ion transport and storage performance, the specific capacity remained 308 mAh⸱g−1 after 100 cycles at 0.1 C, and even at 1 C, the specific capacity of the electrode material instead increases constantly at 142 mAh⸱g−1. According to density functional theory (DFT) calculations, the coexistence of pyridine N content and defects in carbon materials was found to enhance the adsorption energy (E ad) of lithium, and the N4V2 locally show the most negative electrostatic potential (ESP) distribution, which was more favorable for the adsorption of Li+ being positively charged. This insight from DFT studies combined with experimental data emphasizes the favorable impact of pyridine N content and defects on the lithium adsorption process in carbon materials, also providing valuable information for the design and optimization of materials for lithium storage applications. [ABSTRACT FROM AUTHOR]

Paper-based electrochemical sensors provide the opportunity for low-cost, portable and environmentally friendly single-use chemical analysis and there are various reports of surface-functionalized paper electrodes. Here we report a composite paper electrode that is fabricated through designed papermaking using cellulose, carbon fibers (CF), and graphene oxide (GO). The composite paper has well-controlled structure, stable, and repeatable properties, and offers the electrocatalytic activities for sensitive and selective chemical detection. We demonstrate that this CF/GO/cellulose composite paper can be reduced electrochemically using relatively mild conditions and this GO reduction confers electrocatalytic properties to the composite paper. Finally, we demonstrate that this composite paper offers sensing performance (sensitivity and selectivity) comparable to, or better than, paper-based sensors prepared by small-batch surface-modification (e.g., printing) methods. We envision this coupling of industrialized papermaking technologies with interfacial engineering and electrochemical reduction can provide a platform for single-use and portable chemical detection for a wide range of applications. [ABSTRACT FROM AUTHOR]

There are many important cultural relics in China, including many paper relics. Therefore, it is particularly important to find methods of protecting the handwriting in paper relics. This study focuses on the effects acrylic polyurethane materials have on preserving handwriting in paper relics by examining the color change and diffusion of handwriting before and after reinforcement treatments on handwriting materials, including ink, carbon ink, blue-black ink, pure blue ink, red ink, and pencil. The acrylic polyurethane materials have a certain degree of stability and enhance the handwriting of paper relics. We analyzed the acrylic polyurethane reinforcement material in terms of acid resistance, alkali resistance, oxidation resistance, dry heat aging resistance, and durability. The experimental results show that the optimal reinforcement concentration is within 15% for ink, 10% for carbon ink, 20% for blue-black ink, 15% to 20% for pure blue ink, and 3% for red ink and pencil. Finally, the surface of the reinforced paper and handwriting were observed through laser microscopy, SEM, EDS, and infrared spectroscopy and the protective effect of acrylic polyurethane reinforcement material on handwriting was determined. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate how a wide range (10–100%) of cellulose nanofiber (CNF) addition affects the mechanical properties of paper sheets. Young's modulus and tensile strength in the dry and wet states were measured and compared. In the dry state, the Young's modulus increased with the increase of CNF addition. However, the dry specific Young's modulus was constant for all CNF additions, which was one interesting result. The tensile strength increased as the CNF addition increased to 70%; however, there was no further improvement when the CNF addition was greater than 70%, which was another interesting finding. In the wet state, although the Young's modulus decreased when the CNF addition was greater than 20%, the wet tensile strength of the sheets increased almost linearly with increasing CNF addition up to 50%, followed by a slight decline. The maximum wet strength retention reached nearly 10% with 40% CNF addition, despite the higher water uptake (108%). One of advantages of utilizing CNFs as reinforcement agent in paper is that they can improve the wet strength while making paper sheets maintain a higher moisture content. [ABSTRACT FROM AUTHOR]

Waste paper disposed in landfills notably contributes to greenhouse gas (GHG) emissions and impedes more sustainable, circular alternatives, such as recycling. In Hong Kong, this unsustainable approach is currently dominant as 68% of waste paper products are treated in landfills in 2020. To contextualize the impact of local waste paper management and explore mitigation potentials of circular alternatives, this paper develops a quantitative assessment framework around GHG emissions development trajectories. Combining guidelines of the Intergovernmental Panel on Climate Change (IPCC), national GHG inventories, and local parameters from life cycle analysis, five GHG emissions projections were simulated along the Shared Socioeconomic Pathways (SSPs) until 2060. Most recent baselines indicate that Hong Kong's current waste paper treatment generated 638,360 tons CO 2 -eq in 2020, comprising 1,821,040 tons CO 2 -eq from landfill and 671,320 tons CO 2 -eq from recycling, and −1,854,000 tons CO 2 -eq from primary material replacement. Proceeding along a Business-as-Usual scenario under SSP5, GHG emissions will dramatically increase to a net 1,072,270 tons CO 2 -eq by 2060, whereas a recycling-intensive scenario will lead to a net saving of −4,323,190 tons CO 2 -eq. To complement the quantitative evidence on the benefits of waste paper recycling, field research was conducted to explore the feasibility of circular policy innovation from the perspective of recycling stakeholders. These empirical qualitative and quantitative findings from stakeholders' business routines and material transactions provide crucial indications for policy and institutional innovation: Essentially, for Hong Kong to improve waste paper recycling capacities and facilitate a circular economy (CE), local stakeholders require support via fiscal policy measures (financial subsidies or tax reductions) and infrastructure improvements (delivery access and material storage). In sum, this study employs a novel analytical framework combining original qualitative and quantitative evidence to provide policy innovation towards circular, GHG emission-saving waste paper management. [Display omitted] • A new framework assessing greenhouse gas emissions from waste paper treatment. • Exploring long-term carbon neutrality pathways for managing waste paper. • Using empirical evidence from recycling stakeholders for circular policy innovation. [ABSTRACT FROM AUTHOR]

Patients with hypertension are seriously affected by Parkinson's disease than patients with normal blood pressure. Thus, early detection of hypertension and Parkinson disease by monitoring subtle changes in specific biomarkers from body fluids can minimize the risk. This paper proposes a flexible, portable paper-based sensor for simultaneous electrochemical sensing of dopamine and uric acid, using differential pulse voltammetry and electrochemical impedance spectroscopy on electrodeposited Prussian blue on carbon dots@graphite paper. The characteristic peaks of dopamine and uric acid in the differential pulse voltammogram are well separated. Further surface characterization of Prussian blue/carbon dots@graphite paper was carried out by Raman Spectra and Scanning Electron Microscope (SEM). The proposed sensor promoted the fast electrochemical detection of dopamine and uric acid with the linear response for concentrations from 0.2–920.0 μM with a limit of detection 0.015 μM, respectively in an aqueous sample. Excellent flexing stability is demonstrated by the proposed sensor, which can maintain its initial current after being bent more than 300 times. [ABSTRACT FROM AUTHOR]

Commercial Chinese ink was employed to disperse pristine vapor-grown carbon nanofibers (VGCNFs) in aqueous suspensions via horizontal ball milling. The obtained suspension was used to fabricate conductive paper-based composites through filtration-deposition onto filter paper. It was found that the carbon black particles from the Chinese ink helped separate VGCNFs and acted as connection points between the VGCNFs, while the glue reinforced the conduction network. Thus, the VGCNF-ink/paper ternary composite showed sufficiently low sheet resistance. With merely 2.5 mg·cm−2 VGCNFs, the sheet resistance could be reduced to 4.5 Ω·sq−1. As a proof of concept, these paper-based composites were directly used as electrodes of solid-state symmetric electronic double-layer capacitors (EDLCs) and the substrate for the electrodeposition of MnO2 to achieve higher electrochemical performances. The EDLCs fabricated with 2.5 mg·cm−2 VGCNFs showed a specific capacitance of 224 mF·cm−2 at a current density of 1 mA·cm−2, which was retained by 86.4% after 10,000 charge-discharge cycles. Moreover, thanks to the high electrical conductivity and the porous structure, the MnO2 decorated paper-based composites exhibited dramatically enhanced specific capacitance. It is believed that our finding offers an idea to directly utilize commercial Chinese ink for the fabrication of electrode materials. [ABSTRACT FROM AUTHOR]

The global prevalence of diabetes mellitus, a serious chronic disease with fatal consequences for millions annually, is of utmost concern. The development of efficient and simple devices for monitoring glucose levels is of utmost significance in managing diabetes. The advancement of nanotechnology has resulted in the indispensable utilization of advanced nanomaterials in high-performance glucose sensors. Modulating the morphology and intricate composition of transition metals represents a viable approach to exploit their structure/function correlation, thereby achieving optimal electrocatalytic performance of the synthesized catalysts. Herein, a sensitive and rapid Cu-encapsulated Cu 2 S@nitrogen-doped carbon (Cu@Cu 2 S@N–C) hollow nanocubes-functionalized microfluidic paper-based analytical device (μ-PAD) was fabricated. Through a delicate sacrificial template/interface technique and thermal decomposition, inter-connected hollow networks were formed to boost the active sites, and the carbon shell was coated to protect Cu from being oxidation. For application, the constructed μ-PAD is used for glucose sensing utilizing an origami automated sample pretreatment system enabled by a simple application of strong alkaline solution on wax paper. Under optimal circumstances, the Cu@Cu 2 S@N–C electrochemical biosensor exhibits broad detection range of 2–7500 μM (R2 = 0.996) with low detection limit of 0.16 μM (S/N = 3) and high sensitivity of 1996 μA mM−1 cm−2. Additionally, the constructed μ-PAD also exhibited excellent selectivity, stability, and reproducibility. By rationally designing the double-shell hollow nanostructure and introducing Cu-encapsulated inner layer, the synthesized Cu@Cu 2 S@N–C hollow nanocubes show large specific surface area, short diffusion channels, and high stability. The proposed origami μ-PAD has been successfully applied to serum samples without any additional sample preparation steps for glucose determination, offering a new perspective for early nonenzymatic glucose diagnosis. [Display omitted] • Cu@Cu 2 S@N–C hollow nanocubes-based origami μ-PAD sensor was fabricated. • Cu@Cu 2 S@N–C hollow nanocubes possessed large specific surface area and high stability. • Cu@Cu 2 S@N–C hollow nanocubes exhibited excellent electrocatalytic performance for glucose. • The proposed sensor was applied for glucose detection without any additional sample preparation steps. [ABSTRACT FROM AUTHOR]

China is the top emitter of greenhouse gases in the world. Pulp and paper industry is one of eight the strictly regulated industries about carbon emission in China. However, estimates of carbon emissions from China's pulp and paper industry have been suffered from remarkable uncertainty. It is summarized that is aroused by the inaccuracy of factors evaluating energy consumption, and the huge gap between the calculation standards for assessing energy consumption in the production process and the actual level recorded in the factories. This paper re-evaluated the carbon emission of China's pulp and paper industry from the perspective of life cycle assessment, and applied more accurate emission factors, taking account of the actual energy consumption of the production process in factories, to estimate the actual carbon emissions in maximum. It is found that the national standards about the energy consumption quota of China's pulp and paper industry is no longer applicable, and the actual energy consumption regulated in the production process is far better than the advanced level given by the national standards. The greenhouse gas emission have been seriously overestimated approximately 12.00%–56.17% by international organizations. • Life Cycle Analysis of the China's pulp and paper Industry is conducted thoroughly. • The pulp flow of China's pulp and paper Industry is analyzed. • Energy regulated in factory is far better than the national standards' required. • Carbon emissions of China's pulp and paper Industry are overestimated. [ABSTRACT FROM AUTHOR]

Paper products are carbon-intensive and having a huge potential for carbon reduction due to their biomass-oriented characteristics. A uniform standard for total carbon footprint (CF) accounting is vital. However, the existing standards have not yet been unified. Inconsistencies between standards cause difficulties in their use and significantly weaken the credibility and comparability of the carbon footprint of a product (CFP). This work rethought the three most widely used standards (Publicly Available Specification 2050 (PAS2050), Product Life Cycle Accounting and Reporting Standard (GHG Protocol), and Product Life Cycle Accounting and Reporting Standard (ISO14067)) from the life-cycle perspective, and established a more appropriate and comprehensive CF accounting standard for paper products (CFASPP). Sanitary pads were selected as a case study to illustrate the discrepancies between PAS 2050, the GHG Protocol, ISO 14067, and CFASPP, for which the annual production CF results were 1424.60, 1481.08, 1453.57, and 1427.04 tons of carbon dioxide equivalent (CO 2 e) respectively. The main reasons for the different CF results were the cut-off criteria and the inclusion or exclusion of carbon storage, delayed emissions, and energy recovery. Each element increased or decreased 22.57 (carbon storage), 29.96 (cut-off criteria), 10.4 (delayed emissions), and 27.52 (incineration with energy recovery) tons of CO 2 e in the results. With increasing demand, these discrepancies will become increasingly significant and may lead to corporations shouldering more or less carbon emission responsibilities by selecting different standards, which will challenge the fairness of product carbon neutrality management. CFASPP covers all paper product life-cycle stages and places greater emphasis on the aspects of carbon storage, delayed emissions, and energy recovery in incineration, which cannot be ignored for the CF accounting of paper products and other biomass-oriented products. This study aims to provide a more applicable and comprehensive guide for corporations to evaluate the CF of paper products, and to provide a reference for the construction of a carbon-neutral evaluation system. [ABSTRACT FROM AUTHOR]

In the current work, cellulose nanofibers (CNF) were isolated from unbleached kraft pulps of date palm fruit stalks (DPFS) and date palm rachis (DPR) residues by ultrafine grinding. The isolated CNF were characterized by high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), zeta potential measurement, tensile strength properties, contact angle, as well as oil-proof testing. The CNF were applied as a coating material for cardboard paper sheets made from unbleached kraft DPFS and DPR pulps. The results showed that CNF from DPFS and DPR had close dimensions (4–14 nm in width and several microns in length) but their zeta potential was different (−44.65 eV and −51.46 eV for CNF from DPFS and DPR pulps, respectively), as well as their crystallinity (79.4% and 75.5% for CNF from DPFS and DPR pulps, respectively). CNF films from DPFS had tensile stress and Young's modulus of 113.3 MPa and 3.81 GPa, respectively, while those from DPR had tensile stress and Young's modulus of 71.0 MPa and 2.93 GPa, respectively. Films from DPFS CNF showed lower hydrophilicity than that from DPR, nevertheless excellent oil-proof property was obtained in both kinds of films. Coating of cardboard sheets prepared from unbleached kraft DPFS and DPR pulps with CNF layer of about 7-µm thickness resulted in significant changes in some physical properties of paper sheets, such as decreasing their air permeability, water vapor transmission rate, and water absorption; both kinds of CNF imparted paper sheets good oil-proof properties. CNF coating also imparted paper sheets remarkable wet tensile strength properties. The results showed the feasibility of utilizing date palm wastes in producing CNF films with distinct properties from low-cost unbleached kraft pulp, as well as using these CNF as a multi-functional coating material in papermaking industry. • Cellulose nanofibers (CNF) were isolated from unbleached date palm pulps. • The properties of CNF were dependent on the date palm residue used. • CNF films had excellent oil-proof and good mechanical properties. • CNF were successfully used for coating cardboard sheets. • CNF coating improved wet strength, air, oil, and moisture barrier properties. [ABSTRACT FROM AUTHOR]

The fabrication of flexible catalytic films with isolated single/dual‐atomic sites and their integration in wearable electronics is challenging. Herein, an efficient method to prepare atomically dispersed binary Ni/Co‐decorated flexible carbon nanofiber (NiCo‐CNF) film using formamide‐derived cyano‐specific NiCo‐NC as nanofillers was developed. The optimized Ni1Co1‐CNF catalytic film, having large‐area, high density of adjacent Ni‐N4 and Co‐N4 active sites, and good mechanical properties under repeated bending and release conditions, possessed high catalytic activity towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The ORR/OER potential difference (ΔE10) for Ni1Co1‐CNF at 10.0 mA cm−2 was highly comparable with the Pt/C+RuO2 mixture. In addition, flexible Ni1Co1‐CNF‐assembled Zn‐air battery displayed very good mechanical robustness and cycling stability. Our work may inspire the fabrication of other atomic metal‐decorated films for membrane electrocatalysis. [ABSTRACT FROM AUTHOR]

Bio-based polymer composites find increasing research and industrial interest in different areas of our life. In this study, cellulose nanofibers (CNFs) isolated from sugar beet pulp and nanoemulsion prepared from sugar beet pectin and pomegranate extract (PGE) were used for making films and used as coating with antioxidant and antimicrobial activities for paper. For Pectin/PGE nanoemulsion preparation, different ratios of PGE were mixed with pectin using ultrasonic treatment; the antibacterial properties were evaluated to choose the formula with the adequate antibacterial activity. The antioxidant activity of the nanoemulsion with the highest antimicrobial activity was also evaluated. The nanoemulsion with the optimum antibacterial activity was mixed with different ratios of CNFs. Mechanical, greaseproof, antioxidant activity, and antibacterial properties of the CNFs/Pectin/PGE films were evaluated. Finally, the CNFs/Pectin/PGE formulation with the highest antibacterial activity was tested as a coating material for paper. Mechanical, greaseproof, and air porosity properties, as well as water vapor permeability and migration of the coated layer from paper sheets in different media were evaluated. The results showed promising applicability of the CNFs/Pectin/PGE as films and coating material with antibacterial and antioxidant activities, as well as good stability for packaging aqueous, fatty, and acidic food products. [ABSTRACT FROM AUTHOR]

Colored paper is an important industrial paper grade that has applications in various industrial sectors. The increase in coloring efficiency is a key in decreasing the use of dyes, thus can be considered as a "green" process concept; the coloring efficiency depends on the dye retention and dispersion. This work explores the use of nanocellulose, specifically, TEMPO-oxidized cellulose nanofibers (TOCNF), on the coloring efficiency of the preparation of colored paper. Two dyes (i.e. direct blue GL and reactive red 195 (RR195)) were used. Thanks to the large specific surface area and abundant active sites of TOCNF, its use largely improves the direct blue GL retention during the process. The coloring difference (∆E* ab) reached 5.334 with the addition of 13.6 wt% TOCNF and 1.8 wt% direct blue GL in the pulp furnish. The functional group in the dye is a vital factor in determining the dye retention when one chooses TOCNF to enhance the coloring efficiency in the production of colored paper. Furthermore, TOCNF significantly improved the strength properties of both direct blue GL and RR 195 dyed papers. This work demonstrates the potential of nanocellulose in the production of colored paper in improving the coloring efficiency, thus decreasing the environmental impact of the manufacturing process. [Display omitted] • Nanocellulose (i.e. TOCNF) adopted for colored paper preparation • Coloring efficiency improved by TOCNF due to the dye retention improvement • -COO− in TOCNF deteriorating its combination with negatively-charged dye [ABSTRACT FROM AUTHOR]

The electromagnetic wave irradiation has obstructed the precise operation of the high-tech electronic equipment and threatened the health of the bodies during the 5G era. It is critical to develop electromagnetic interference (EMI) shielding materials with remarkable shielding effectiveness along with lightweight and flexible properties, while the integrations of the heat management performances have been gradually indispensable, especially in wearable electronic device applications. Anchoring the Ti 3 C 2 T x MXene nanosheets on the surfaces of the recycled carbon fibers (RCF) and assembling heterostructure can be regarded as effective strategies, while simultaneously solving the conductivity reduction and the corresponding performance degradation bottlenecks of the thermal-recycling carbon fiber. The construction of the RCF-MXene paper performs remarkable EMI shielding performance of 45.7 dB, while the specific SE/t can be improved to 7723.85 dB cm2 g-1, along with impressive photothermal and electrothermal conversion abilities. After coating PDMS layers, the flexible RCF-MXene@PDMS film maintains stable EMI shielding performance when experiencing in-situ electrothermal conversion and after 10000-cycle mechanical deformation processes. Exhibiting multifunctionality by facile synthesis strategies, the RCF-MXene-based materials provide great potential as next-generation candidates in wearable electronic devices, together with promoting the advancement of the sustainable reuse of the carbon fibers resources. [Display omitted] [ABSTRACT FROM AUTHOR]

Handheld detection platform integrating ratiometric fluorescent N,P co-doped carbon dots (N,P-CDs) paper strip, smartphone, and 3D-printed accessory corroborates its efficacy for visual quantitative detection of Mn(VII) and GSH via a continuous fluorescence color shift. N,P-CDs were synthesized by hydrothermal treatment of 1,8-diaminonaphthalene, phosphoric acid, and formamide. Inspiringly, with increasing Mn(VII) concentrations, blue emission of N,P-CDs decreases gradually at 445 nm and a ratio rising orange band emerges at 600 nm under 340 nm excitation, which concurrently exhibits continuous fluorescence color variation of blue, purplish blue, purplish pink, pink, to orange. Subsequent addition of GSH renders orange fluorescence of N,P-CDs@Mn(VII) gradually quench but blue peak slightly enhance, accompanied by the fluorescence color successively returning from orange to blue. The RGB values of the resulting images were precisely defined by a color recognition application within the smartphone, and the R/B values could be employed for Mn(VII) and GSH quantification with linear ranges of 0 − 40 μM and 0 − 28 μM, respectively, as well as limits of detection of 24.49 nM and 21.41 nM, respectively. It is solicitously anticipated that our research will provide novel insight for the development of effective sensing protocol and the enlargement of practical application prospect. • Handheld detection integrates FL paper strip, smartphone and 3D-printed accessory. • Paper strip is stained by single ratiometric-FL CDs for Mn(VII) and GSH sensing. • High sensitivity is gotten due to well-resolved FL color shift of paper strip. [ABSTRACT FROM AUTHOR]

Sheet-like transition metal sulfides have promising applications in photocatalysis and energy conversion. This study provides a petal-like Cu 2 WS x nanosheet structure supported on carbon paper (CP) synthesized by a simple one-step solvothermal method. Cu 2 WS x microstructures with different morphologies were synthesized by solvothermal vulcanization of thioacetamide (TAA) at different concentrations. The Cu 2 WS x /CP was used as the counter electrode of DSSCs and compared with the Pt FTO electrode. It was proved that Cu 2 WS x -7 M/CP had the best electrocatalytic performance and obtained 9.01% photoelectric conversion efficiency. The different sulfide concentration changes the morphology of Cu 2 WS x and continuously affects the specific surface area and catalytic activity of the material. The better electrochemical performance shows that Cu 2 WS x /CP is expected to become a substitute for expensive Pt CE materials in dye-sensitized solar cells (DSSCs). [Display omitted] • One-step solvothermal method for the growth of petal-like Cu 2 WS x on carbon paper. • The effect of sulfide concentration on Cu2WSx was explored for the first time by TAA. • For the first time, Cu 2 WS x /CP was used as a counter electrode for DSSCs. • At a sulfide concentration of 7 M, Cu 2 WS x /CP exhibited a value of 9.01% PCE (Pt 7.67%). [ABSTRACT FROM AUTHOR]

The microencapsulation of flame retardants can avoid the problems of water absorption and loss. In this paper, hydrophobic microcapsule-encapsulated ammonium polyphosphate (HMAPP) was prepared by ion exchange and Stöber method and applied to the preparation of hydrophobic flame-retardant kraft paper by impregnation. The microscopic morphology and element analysis of the hydrophobic microcapsules tested by TEM and SEM showed that nano-scale particles with a size of about 100 nm have been successfully prepared, and the core–shell structure has been formed. HMAPP constructed a rough structure with low surface energy on the surface of kraft paper and provided the kraft paper with hydrophobic property. The water contact angle of kraft paper reached 122.7 ° after treated by HMAPP, while it also enhanced the physical strength of the paper. Kraft had the self-extinguishing phenomenon after treated by HMAPP, which attached to the surface of kraft paper were heated and melted to release ammonia to dilute combustible gas and oxygen, and formed a flame-retardant layer containing SiO2 particles, phosphoric acid, metaphosphoric acid, pyrophosphoric acid, and carbon flakes on the fiber surface. There were C–C, C–O–C bonds in the carbon layer after flame-retardant treatment, indicating that the pentose contained in fiber has not been completely destroyed. In addition, the presence of Si and P elements in the residual carbon indicates that the decomposed flame retardant adheres to the surface of the fiber to block the heat transfer and flame spread. [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]

Following the example of photovoltaics, one approach to large‐scale photocatalytic hydrogen production is the irradiation of a correspondingly large catalyst area. Paper production is a process in which large areas can already be produced based on the main component: cellulose. Herein, the TiO2 photocatalyst modification PC500, which also uses platinum nanoparticles as a cocatalyst, is supported in two different ways using cellulose. On the one hand, the catalyst is fixed to the surface of a commercial filter paper and, on the other hand, a photocatalytic paper is produced. For comparison, the catalyst is immobilized by means of drop coating using Nafion and measured as a suspension. The cellulose‐stabilized films are active and hydrogen production is comparable with the activity obtained from the drop‐coating method. The experiments show that the aggregation behavior of cellulose can be used to produce photocatalytically active films. The preparation is easy and can be applied to different kinds of (photo)catalysts. Although the films are very active, their stability during reaction due to swelling and hydrogen production must be further improved. [ABSTRACT FROM AUTHOR]

• Black liquor gasification was coupled with calcium looping. • Calcium looping for CO 2 capture and H 2 production was compared. • CO 2 capture route (39 €/t) was less expensive than H 2 production route (48.8 €/t). • CO 2 avoided cost was highly dependent on capital cost of black liquor gasification. • Export of H 2 had the lowest CO 2 avoided cost among black liquor gasification cases. Although considered one of the major energy-intensive industries (EIIs), the pulp and paper industry has also the potential for energy production from an industrial waste, black liquor. This study proposes black liquor gasification (BLG) coupled with calcium looping (CaL) as a CO 2 capture route for the pulp and paper industry. BLG with H 2 production (BLG-CaL-H 2), BLG with gas turbine combined cycle (BLG-CaL-GT) or with solid oxide fuel cell (BLG-CaL-SOFC) were considered. The dependence of carbon capture and storage (CCS) cost on the natural gas, limestone, electricity imported and H 2 sale prices aside the expenditures related with BLG-CaL were evaluated. The CCS route, based on CaL retrofitted to the pulp and paper plant, was found to have a lower cost of CO 2 avoided (39.0 €/tCO 2) when compared with BLG-CaL (48.8–57.1 €/tCO 2). Between the BLG-CaL scenarios, BLG-CaL-H 2 presented the lowest cost of CO 2 avoided (48.8 €/tCO 2) but the highest energy penalty. Based on the thermodynamic performance, it was shown that CaL retrofit and BLG-CaL-SOFC presented the best overall performance, turning the electricity importer reference plant into electricity exporter. The economic sensitivity showed that the capital requirement of BLG-CaL has a strong effect on the cost of CO 2 avoided for all alternatives. The H 2 production is also strongly affected by the H 2 sale price while BLG-CaL-SOFC and BLG-CaL-GT are strongly dependent on natural gas price. [ABSTRACT FROM AUTHOR]

Herein, a simple method to prepare porous carbon that inhibits hydrogen evolution is used, which has enormous advantages for both capacitors and lead‐acid batteries. The quantitative filter paper spongy porous carbon (SQFPC) is successfully synthesized by the two‐step method. SQFPC displays a porous, spongy structure with a large specific surface area (1847 m2 g−1). In electrochemical tests, SQFPC exhibits high specific capacitance (244 F g−1 at 1 A g−1) and a capacitance retention rate of 72.5% at 40 A g−1. In addition, the capacity of the battery with 0.5 wt% SQFPC is improved by 57.6% at a discharge rate of 0.1C, and the cycle life under the high‐rate partial state of charge is 9.3 times that of the blank battery. The enhanced battery performance is related to the unique structure and surface functional groups of carbon, which speed up ion movement inside the battery and provide active sites for lead deposition. [ABSTRACT FROM AUTHOR]

Recently, cellulose nanofibers (CNF) have gained significant attention as renewable and high-value nano-biomaterial that has the potential to regulate microstructures and enhance the strength properties of paper products. However, the distribution of CNF in paper sheets may impact the physical properties differently, requiring further understanding. In this study, the effects of different CNF distributions on pore sizes and strength properties in paper sheets were investigated. The hypothesis is that the different distributions of CNF within paper sheets can exhibit different functions in improving the physical properties of paper sheets. Three types of paper sheets containing CNF were respectively prepared by mixing with pulp (CNF (mixture)), distribution on the surface of paper sheets (CNF (surface)) and adding in the middle of paper sheets (CNF (middle)). Results show that CNF can narrow the pore size distribution of paper sheets, particularly in samples with CNF (surface) and CNF (middle) that form dense CNF layers. The highest mechanical strength improvement was observed with mixed CNF. X-ray photoelectron spectroscopy (XPS) analysis revealed that this is due to the strong hydrogen bonding between CNF and pulp fibers, resulting from a large bonding area and effective contact with pulp fibers. This study provides a new perspective on CNF distribution within paper sheets for improving wet web strength properties. [Display omitted] • Three different CNF distribution models within paper sheet were proposed. • The effects of CNF distributions on strength properties of paper sheets were investigated. • CNF (mixture) exhibits better pore size modification than that of CNF (surface) and CNF (middle). • The highest mechanical strength was observed within CNF (mixture) paper sample. • The hydrogen bonding area between CNF and pulp fibers were visually characterized. [ABSTRACT FROM AUTHOR]

In order to facilitate monitoring of cannabidiol (CBD), we devised a gold immunochromatographic sensor based on a specific monoclonal antibody (mAb). To prepare the antigen, a novel hapten with CBD moiety and a linear carbon chain was employed. By utilizing hybridoma technology, a specific mAb was screened and identified that exhibited a 50% maximal inhibitory concentration against CBD ranging from 28.97 to 443.97 ng/mL. Extensive optimization led to the establishment of visual limits of detection for CBD, achieving a remarkable sensitivity of 8 μg/mL in the assay buffer. To showcase the accuracy and stability, an analysis of CBD-spiked wine, sparkling water, and sports drink was conducted. The recovery rates observed were as follows: 88.4–109.2% for wine, 89.9–107.8% for sparkling water, and 83.2–95.5% for sports drink. Furthermore, the coefficient of variation remained impressively low, less than 4.38% for wine, less than 2.07% for sparkling water, and less than 6.34% for sports drink. Importantly, the developed sensor exhibited no cross-reaction with tetrahydrocannabinol (THC). In conclusion, the proposed paper sensor, employing gold nanoparticles, offers a user-friendly and efficient approach for the precise, rapid, and dependable determination of CBD in products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Filter paper is used as carbon source to prepare highly porous N-doped carbon. • KHCO 3 is chosen as the activator because it is safe and non-corrosive. • Addition of urea at the activation step significantly improves the surface area. • At 0 °C and 20 bar, the carbon shows high CO 2 uptake of 19.65 mmol/g. Herein, we presented the preparation of N-doped porous carbon from lab used filter paper. Filter paper was first carbonized at 500 °C. The obtained carbon was then pyrolyzed with KHCO 3 and urea. Effects of KHCO 3 activation on the carbons' physicochemical properties were thoroughly investigated. The derived carbon materials were also tested for CO 2 adsorption with pressure up to 20 bar. The carbons exhibited very high CO 2 uptake of 19.65 mmol/g at 0 °C and 20 bar. The correlations between adsorption performances and the carbons' physicochemical properties at 1/20 bar were analyzed and discussed. [ABSTRACT FROM AUTHOR]

This comprehensive review explores recent advancements in the manufacturing of cellulose nanofiber (CNF)-based cellulose nanopaper (CNP). The analysis delves into customizing CNPs through nanofiber manufacturing, mechanical refining, and chemical treatments. The report underscores the growing interest in CNPs derived from CNF due to their exceptional properties and eco-friendly attributes. CNP strength significantly enhanced through mechanical refining encompassing cellulose nanofibrillation were breaking down of cellulose into nanofibers takes place. Conversely, dense CNF network formed through filtration and casting method. Chemical treatments such as dispersion, functionalization, and coating methods followed by drying and consolidation introduce custom functionalities for diverse applications. These applications span packaging, electronics, energy harvesting, EMI shielding, optoelectronics, nanogenerators, transparent conducting films, water treatment, bioelectronics, and neuromorphic computing. The study conducts an in-depth investigation to assess CNP's effects on promoting sustainability and minimizing environmental waste, making a significant contribution to the circular economy. This investigation underscores the pursuit of innovation and aligns with the principles of progressing toward a more environmentally sustainable future. [Display omitted] • Explores CNF production, refining and chemical treatments for CNP customization. • Remarkable properties of CNP draw academic and industrial interest. • CNP applied in packaging, electronics, energy, and environmental science. • Investigates role of CNP in circular economy. • Emphasizes CNPs as eco-friendly, fostering innovation and sustainability. [ABSTRACT FROM AUTHOR]

Importantly, trends and developments of this interaction found in both biosensors and bioassays have opened new perspectives in the sensing field and are therefore also of great interest to the sensor community. (i) Biosensors are chemical sensors in which the recognition system utilizes a biochemical mechanism for the interaction process in/at the recognition layer. [Extracted from the article]

In this work, we demonstrate a novel device structure with a dual‐electron blocking layer (2EBL) configuration to improve the capacitance‐voltage (CV) behavior without compromising other critical performances of bottom‐emission red organic light‐emitting diode (OLED). We started the work from studying the influence of electron blocking materials (EBMs) on various device characteristics including capacitance behavior. It is found that with conventional single EBL configuration, EBM with a deep highest occupied molecular orbital (HOMO) level tends to have high voltage yet low capacitance, while EBM with a shallow HOMO has the opposite behavior. To combine the advantages of low voltage and low capacitance, we investigate the employment of 2EBL configuration. 2 EBMs were developed, where EBM1 has a HOMO of ‐5.17 eV and a faster hole mobility of 21×10‐5 cm2/Vs, while EBM2 has a deeper HOMO level of ‐5.22 eV and a slower mobility of 14×10‐5 cm2 /Vs. Bottom emission red OLEDs A‐D with single EBM1, single EBM2, EBM1/EBM2, and EBM2/EBM1 were fabricated, respectively. The characterization of OLEDs A‐D reveals that OLED C reaches a balanced performance, at 10 mA/cm2 achieving a low voltage of 3.5 V, a low maximum capacitance per unit area (u‐Cmax) of 36 nF/cm2 and an accumulated charges per unit area (u‐Q) of 8 nC/cm2, while maintaining a high EQE of 30.6% and a long lifetime LT95 of 11,300 h. Moreover, Electrochemical Impedance Spectroscopy (EIS) measurements highlight the differences in bulk resistance among the OLED configurations, emphasizing the importance of EBL composition and arrangement in optimizing OLED performance. Low capacitance of OLED ensures a quick signal response and hence quick refresh rate, especially at low gray scale scenarios. Reduction of capacitance through EBL optimization is believed to be the best strategy, comparing to tuning emitter and hosts which is more likely to affect other key performances of OLED. Although this work is based on study of red OLED, the same scheme can be extended to other colors. [ABSTRACT FROM AUTHOR]

[Display omitted] • A red-emissive carbon dots based fluorescent nanosensor was fabricated for sensing carbendazim. • R-CDs were synthesized by solvothermal method and surface charge engineering with excellent performance. • The novel nanosensor exhibited LOD of 3.5 ng/mL and range of 10–250 ng/mL for carbendazim. • Real application in Lotus seeds confirmed the excellent reliability with satisfactory recovery. • Visual paper-based sensor with smartphone was developed for rapid on-site carbendazim detection. Trace detection of carbendazim (CBZ), a worldwide used pesticide, in crops and foods is important and urgent to reduce risks to human health. Herein, newly red-emissive carbon dots (R-CDs) based fluorescent and smartphone-integrated paper sensors were developed for highly-selective, and -sensitive rapid sensing of CBZ. R-CDs were synthesized from citric acid and urea via a DMF solvothermal method, which showed excellent analytical performance due to abundant carboxyl groups on the surface and long emission wavelength to avoid autofluorescence interference of matrix. According to the red fluorescence quenching by CBZ via π-π interaction and photoinduced electron-transfer effect, the newly fluorescent nano sensor could realize CBZ sensing within 3 min with high selectivity out of the other six interfering pesticides, as well as fascinating sensitivity with an ultralow detection limit of 3.5 ng/mL. The practicable application in the spiked medicinal Lotus seeds samples exhibited satisfactory recoveries of 95.5%-108.3%. The portable paper-based sensor fabricated by depositing R-CDs on the filter paper enabled quantitative readout of test strip results assisted with a smartphone, providing a rapid on-site tool for CBZ detection in medicinal foods. This is the first report of a novel, sensitive, and portable R-CDs based sensing platform for simple, cost-effective, and rapid on-site detection of CBZ in the field of food safety with great application potential. [ABSTRACT FROM AUTHOR]

Carbon cloth and carbon paper have unique characteristics such as conductivity, mechanical strength, porosity, reduced dimensions, and adjustable size and shape. With these materials, different simple modification strategies can be employed, with emphasis on the direct growth of metal-based catalysts through single-step hydrothermal methods. Thus, owing to these interesting features, highly efficient, versatile, and disposable electrochemical (bio)sensors based on carbon cloth and carbon paper have been designed for biomolecules, biomarkers, and hazardous and chemical compounds detection in clinical, environmental and food samples, as well as in industrial products. Moreover, the advantage of facile integration in miniaturized and portable devices, envisages their successful application in point-of-care diagnostics and in-situ measurements. Therefore, this review highlights the main advances and the current research gaps concerning the design of these novel electroanalytical tools. • CC and CP present high electrical conductivity, porosity, and adjustable size/shape. • Single-step hydrothermal methods are the most used for CC and CP modification. • CC and CP (bio)sensors successfully used in clinical, environmental and food analysis. • Excellent performance of CP and CC (bio)sensors reaching sub-micromolar levels of LOD. • Facile integration in miniaturized and portable devices for in-situ measurements. [ABSTRACT FROM AUTHOR]

[Display omitted] • The dual-emission ratiometric fluorescent probe was prepared by a facile hydrothermal synthesis method. • The quantification of Pb2+ was based on the efficient FRET between NCDs and AuNCs. • The sensor has good selectivity and anti-interference ability with satisfactory recovery in real water samples. • A paper-based sensor was fabricated for visual semi-quantitative detection by color change. Ratiometric fluorescent sensors could effectively eliminate the interference of spontaneous fluorescence or instrument fluctuation to improve the analysis sensitivity and accuracy. In this work, a dual-emission nitrogen-doped carbon dots/AuNCs (NCDs-AuNCs) nanohybrid was fabricated under mild conditions by the hydrothermal method, without additional coupling agents, which is facile and environmentally friendly. The prepared nanohybrid was employed for the sensitive detection of Pb2+. The sensor exhibited dual emission peaks at 460 and 625 nm with efficient fluorescence resonance energy transfer under a single excitation wavelength of 360 nm, in which the red fluorescence of AuNCs was enhanced and the blue fluorescence of NCDs was slightly quenched with the presence of Pb2+. The quantitative analysis of Pb2+ was performed upon the change of both fluorescence intensities. The sensor was successfully used for Pb2+ detection in real water samples with satisfactory spiking recoveries in a range of 91.0%–101.3% and low relatively standard deviations (RSDs < 3%), which exhibited good selectivity and anti-interference ability. In addition, a paper-based sensor was fabricated by immobilizing the nanohybrids on filter paper, which enables the visual semi-quantitative determination of Pb2+ by the naked eye through the color transition from blue to pink. The prepared NCDs-AuNCs nanohybrids showed great application potential in environmental water monitoring in an efficient and green way. [ABSTRACT FROM AUTHOR]

In response to food packaging improvements, this study investigates changes in mechanical and thermal barrier properties of pigment-based paper coatings when cellulose nanocrystals (CNC) and cellulose nanofibers (CNF) are added to the formulation. Stable dispersions of all coating components were formed between pH 7–9 (zeta potential > |30 mV|) except CNF, which favored stable dispersions at higher pH. Hydrodynamic diameters (Dh) of CNC and CNF decreased when interacting with calcium carbonate ions (Ca2+ and CO32-); however, latex binder and dispersant diameters were unaffected by the presence of CaCO3 in solution. Thermal barrier performance was quantified by measuring ΔT across coated samples, with and without nanoparticle additives. Both CNC and CNF additives significantly contributed to the ΔT measured, with the best result recorded for 2 wt% CNF, pH 7, and a drying rate of 25 °C/min. This sample recorded 37 ± 6 °C higher than the ΔT for baseline coatings (without additive). Dynamic mechanical analysis (DMA) showed a higher storage modulus for all samples containing CNC and/or CNF compared with the baseline coating, suggesting a material with greater resistance to deformation from applied load. Higher dissipation energy was also observed; however, lower tan delta values suggest improved mechanical properties with both additives. [ABSTRACT FROM AUTHOR]

BACKGROUND: Two‐ and three‐dimensional porous activated carbon (C)‐based symmetrical supercapacitors show great potential for extraordinary gravimetric performance as sustainable energy storage. However, the applications of portable and microdimensional supercapacitors are limited by their low volumetric performance stemming from reduced density resulting from increased porosity and high fabrication costs. This study aimed to demonstrate the high gravimetric–volumetric performance of symmetrical supercapacitors from biomass‐based porous carbon‐sources materials through an environmentally benign development method. Unique porous C sourced from TENERA‐type palm oil stick waste was prepared using potassium hydroxide (KOH) as an activating agent. The electrode set resembled a solid plate with an encapsulation density of ≈1.40 g cm−3. RESULT: The study used superior gravimetric–volumetric electrode materials, including an adjusted specific surface area of 934 m2 g−1, single‐doped optimization, and a hollow paper‐stack‐like morphological structure with a high C content of 91%. The results showed that the best electrode in the 1 mol L−1 H2SO4 electrolytes exhibited a high gravimetric capacitance of 233 F g−1 and an extraordinary volumetric capacitance of 326 F cm−3 at 1 A g−1. Furthermore, their coulombic efficiency was ≈99.1% at 10 A g−1. The symmetrical electrode device performed a high gravimetric–volumetric energy density of 19.03 Wh kg−1 and 26.6 Wh L−1 at a maximum output power density of 1.7 kW kg−1 and 1.9 kW L−1, respectively. CONCLUSION: These results indicate that the applied method development and the C‐biomass‐based electrode material design could achieve a high, well‐matched gravimetric–volumetric performance balance in symmetric supercapacitor devices. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]