Hierarchical porous carbons from polysaccharides carboxymethyl cellulose, bacterial cellulose, and citric acid for supercapacitor

Carboxymethyl cellulose-based photothermal film: A sustainable packaging with high barrier and tensile strength for food long-term antibacterial protection

Traditional packaging materials feed the growing global food protection. However, these packaging materials are not conducive to environment and have not the ability to kill bacteria. Herein, a green and simple strategy is reported for food packaging protection and long-term antibacterial using carboxymethylcellulose-based photothermal film (CMC@CuS NPs/PVA) that consists of carboxymethyl cellulose (CMC) immobilized copper sulfide nanoparticles (CuS NPs) and polyvinyl alcohol (PVA). With satisfied oxygen transmittance (0.03 cc/m2/day) and water vapor transmittance (163.3 g/m2/day), the tensile strength, tear strength and burst strength reached to 3401.2 N/m, 845.7 mN and 363.6 kPa, respectively, which could lift 4.5 L of water. The composite film had excellent photothermal conversion efficiency and photothermal stability. Under the irradiation of near infrared (NIR), it can rapidly heated up to 197 °C within 25 s. The antibacterial analysis showed that the inhibition rate of composite film against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) could all reach >99 %. Furthermore, the synthesized CuS NPs was well immobilized and the residual rate of copper kept 98.7 % after 10 days. Noticeably, the composite film can preserve freshness of strawberries for up to 6 days. Therefore, the composite film has potential application for food antibacterial protection.

MXene-Derived TiO2/Starbon Nanocomposite as a Remarkable Electrode Material for Coin-Cell Symmetric Supercapacitor

In this study, the synthesis of a MXene (Ti3C2Tx)-derived TiO2/starbon (M-TiO2/Starbon-800 °C) nanocomposite using a facile calcination method is explored. High-temperature exposure transforms layered Ti3C2Tx into rod-like TiO2 and starbon into amorphous carbon. The resulting M-TiO2/Starbon-800 °C nanocomposite exhibits a significantly larger surface area and pore volume compared to its individual components, leading to superior electrochemical performance. In a three-electrode configuration, the nanocomposite achieved a specific capacitance (Csp) of 1352 Fg⁻¹ at 1 Ag⁻¹, while retaining more than 99% of its Csp after 50 000 charge/discharge cycles. Furthermore, when incorporated into a two-electrode symmetric coin cell, it demonstrates a Csp of 115 Fg⁻¹ along with exceptional long cycle life. Moreover, the device shows an energy density (ED) of 51 Whkg-1 and a power density (PD) of 7912 Wkg-1 at 5 Ag-1. The enhanced charge storage is attributed to the formation of a porous structure with a high specific surface area resulting from the interaction between M-TiO2 nanorods and starbon, which facilitates efficient ion penetration.

Aromatic biomass (torch ginger) leaf-derived three-dimensional honeycomb-like carbon to enhance gravimetric supercapacitor

BACKGROUND

Porous carbon electrode (PCE) is identified as a highly suitable electrode material for commercial application due to its production process, which is characterized by simplicity, cost-effectiveness and environmental friendliness. PCE was synthesized using torch ginger (Etlingera elatior (Jack) R.M. Smith) leaves as the base material. The leaves were treated with different concentrations of ZnCl2 , resulting in a supercapacitor cell electrode with unique honeycomb-like three-dimensional (3D) morphological pore structure. This PCE comprises nanofibers from lignin content and volatile compounds from aromatic biomass waste.

RESULTS

From the characterization of physical properties, PCE-0.3 had an impressive amorphous porosity, wettability and 3D honeycomb-like structural morphology with a pore framework consisting of micropores and mesopores. According to the structural advantages of 3D hierarchical pores such as interconnected honeycombs, PCE-0.3 as supercapacitor electrode had a high specific capacitance of up to 285.89 F g-1 at 1 A. Furthermore, the supercapacitor exhibited high energy and power density of 21.54 Wh kg-1 and 161.13 W kg-1 , respectively, with a low internal resistance of 0.059 Ω.

CONCLUSION

The results indicated that 3D porous carbon materials such as interconnected honeycombs derived from the aromatic biomass of torch ginger leaves have significant potential for the development of sustainable energy storage devices. © 2023 Society of Chemical Industry.

Carboxymethyl cellulose-based materials as an alternative source for sustainable electrochemical devices: a review

In electrochemistry, bio-based materials are preferred over the traditional costly and synthetic polymers due to their abundance, versatility, sustainability and low cost. One of the bio-based polymers is carboxymethyl cellulose (CMC) which has become an overarching material in electrochemical devices pertaining to its amphiphilic nature with multi-carbon functional groups. Owing to its flexible framework with fascinating groups on its surface like hydroxide (-OH) and carboxylate (-COO-), CMC is able to be modified into conducting materials by blending it with other biopolymers, synthetic polymers, salts, acids and others. This blending has improved the profile of CMC by exploiting the ability of hydrogen bonding, swelling, adhesiveness and dispersion of charges and ions. These properties of CMC have made it possible to utilize this bio-sourced polymer in several applications as a conducting electrolyte, binder in electrodes, detector, sensor and active material in fuel cells, actuators and triboelectric nanogenerators (TENG). Thus, CMC based materials are cheap, environment friendly, hydrophilic, biodegradable, non-toxic and biocompatible which render it a desirable material in energy storage devices.

Magnetic Bacterial Cellulose Biopolymers: Production and Potential Applications in the Electronics Sector

Bacterial cellulose (BC) is a biopolymer that has been widely investigated due to its useful characteristics, such as nanometric structure, simple production and biocompatibility, enabling the creation of novel materials made from additive BC in situ and/or ex situ. The literature also describes the magnetization of BC biopolymers by the addition of particles such as magnetite and ferrites. The processing of BC with these materials can be performed in different ways to adapt to the availability of materials and the objectives of a given application. There is considerable interest in the electronics field for novel materials and devices as well as non-polluting, sustainable solutions. This sector influences the development of others, including the production and optimization of new equipment, medical devices, sensors, transformers and motors. Thus, magnetic BC has considerable potential in applied research, such as the production of materials for biotechnological electronic devices. Magnetic BC also enables a reduction in the use of polluting materials commonly found in electronic devices. This review article highlights the production of this biomaterial and its applications in the field of electronics.

Biopolymers-Derived Materials for Supercapacitors: Recent Trends, Challenges, and Future Prospects

Supercapacitors may be able to store more energy while maintaining fast charging times; however, they need low-cost and sophisticated electrode materials. Developing innovative and effective carbon-based electrode materials from naturally occurring chemical components is thus critical for supercapacitor development. In this context, biopolymer-derived porous carbon electrode materials for energy storage applications have gained considerable momentum due to their wide accessibility, high porosity, cost-effectiveness, low weight, biodegradability, and environmental friendliness. Moreover, the carbon structures derived from biopolymeric materials possess unique compositional, morphological, and electrochemical properties. This review aims to emphasize (i) the comprehensive concepts of biopolymers and supercapacitors to approach smart carbon-based materials for supercapacitors, (ii) synthesis strategies for biopolymer derived nanostructured carbons, (iii) recent advancements in biopolymer derived nanostructured carbons for supercapacitors, and (iv) challenges and future prospects from the viewpoint of green chemistry-based energy storage. This study is likely to be useful to the scientific community interested in the design of low-cost, efficient, and green electrode materials for supercapacitors as well as various types of electrocatalysis for energy production.

Porous Carbon Spheres Derived from Hemicelluloses for Supercapacitor Application

With the increasing demand for dissolving pulp, large quantities of hemicelluloses were generated and abandoned. These hemicelluloses are very promising biomass resources for preparing carbon spheres. However, the pore structures of the carbon spheres obtained from biomass are usually poor, which extensively limits their utilization. Herein, the carbon microspheres derived from hemicelluloses were prepared using hydrothermal carbonization and further activated with different activators (KOH, K2CO3, Na2CO3, and ZnCl2) to improve their electrochemical performance as supercapacitors. After activation, the specific surface areas of these carbon spheres were improved significantly, which were in the order of ZnCl2 > K2CO3 > KOH > Na2CO3. The carbon spheres with high surface area of 2025 m2/g and remarkable pore volume of 1.07 cm3/g were achieved, as the carbon spheres were activated by ZnCl2. The supercapacitor electrode fabricated from the ZnCl2-activated carbon spheres demonstrated high specific capacitance of 218 F/g at 0.2 A/g in 6 M KOH in a three-electrode system. A symmetric supercapacitor was assembled in 2 M Li2SO4 electrolyte, and the carbon spheres activated by ZnCl2 showed excellent electrochemical performance with high specific capacitance (137 F/g at 0.5 A/g), energy densities (15.4 Wh/kg), and good cyclic stability (95% capacitance retention over 2000 cycles).

Cellulose-Derived Nanostructures as Sustainable Biomass for Supercapacitors: A Review

Sustainable biomass has attracted a great attention in developing green renewable energy storage devices (e.g., supercapacitors) with low-cost, flexible and lightweight characteristics. Therefore, cellulose has been considered as a suitable candidate to meet the requirements of sustainable energy storage devices due to their most abundant nature, renewability, hydrophilicity, and biodegradability. Particularly, cellulose-derived nanostructures (CNS) are more promising due to their low-density, high surface area, high aspect ratio, and excellent mechanical properties. Recently, various research activities based on CNS and/or various conductive materials have been performed for supercapacitors. In addition, CNS-derived carbon nanofibers prepared by carbonization have also drawn considerable scientific interest because of their high conductivity and rational electrochemical properties. Therefore, CNS or carbonized-CNS based functional materials provide ample opportunities in structure and design engineering approaches for sustainable energy storage devices. In this review, we first provide the introduction and then discuss the fundamentals and technologies of supercapacitors and utilized materials (including cellulose). Next, the efficacy of CNS or carbonized-CNS based materials is discussed. Further, various types of CNS are described and compared. Then, the efficacy of these CNS or carbonized-CNS based materials in developing sustainable energy storage devices is highlighted. Finally, the conclusion and future perspectives are briefly conferred.

A Comparative Evaluation of Sustainable Binders for Environmentally Friendly Carbon-Based Supercapacitors

Environmentally friendly energy storage devices have been fabricated by using functional materials obtained from completely renewable resources. Gelatin, chitosan, casein, guar gum and carboxymethyl cellulose have been investigated as sustainable and low-cost binders within the electrode active material of water-processable symmetric carbon-based supercapacitors. Such binders are selected from natural-derived materials and industrial by-products to obtain economic and environmental benefits. The electrochemical properties of the devices based on the different binders are compared by using cyclic voltammetry, galvanostatic charge/discharge curves and impedance spectroscopy. The fabricated supercapacitors exhibit series resistance lower than a few ohms and values of the specific capacitance ranged between 30 F/g and 80 F/g. The most performant device can deliver ca. 3.6 Wh/kg of energy at a high power density of 3925 W/kg. Gelatin, casein and carboxymethyl cellulose-based devices have shown device stability up to 1000 cycles. Detailed analysis on the charge storage mechanisms (e.g., involving faradaic and non-faradaic processes) at the electrode/electrolyte interface reveals a pseudocapacitance behavior within the supercapacitors. A clear correlation between the electrochemical performances (e.g., cycle stability, capacitance retention, series resistance value, coulombic efficiency) ageing phenomena and charge storage mechanisms within the porous carbon-based electrode have been discussed.

Cellulose nanofiber derived carbon aerogel with 3D multiscale pore architecture for high-performance supercapacitors

Carbon materials are highly promising electrode materials for supercapacitors, due to their hierarchical porous structure and large specific surface area. However, the limited specific capacitance and inferior rate capability significantly prevent their practical application. Herein, 3D interconnected hierarchical porous carbon aerogels (CNFAs) through engineering the pyrolysis chemistry of CNF are developed. The obtained CNFAs effectively improve the carbon yield and suppress the volume shrinkage, as well as have robust mechanical properties. As a supercapacitor electrode, the CNFAs-17% electrode exhibits an ultrahigh capacitance of 440.29 F g^-1 at 1 A g^-1, significantly superior to most reported biomass-based carbon materials. Moreover, the CNFAs-17% assembled symmetric supercapacitor (SSC) achieves an outstanding rate capability (63.29% at 10 mA cm^-2), high areal energy density (0.081 mWh cm^-2), and remarkable cycling stability (nearly 100% capacitance retention after 7000 cycles). This work offers a simple, effective strategy towards the preparation of promising electrode materials for high-performance energy storage applications.

Nitrogen and oxygen Co-doped porous carbon derived from yam waste for high-performance supercapacitors

It is a considerable challenge to produce a supercapacitor with inexpensive raw materials and employ a simple process to obtain carbon materials with a high specific surface area, rich pore structure, and appropriate doping of heterogeneous elements. In the current study, yam waste-derived porous carbon was synthesized for the first time by a two-step carbonization and KOH chemical activation process. An ultra-high specific surface area of 2382 m2 g-1 with a pore volume of 1.11 cm3 g-1 and simultaneous co-doping of O-N was achieved for the optimized sample. Because of these distinct features, the optimized material exhibits a high gravimetric capacitance of 423.23 F g-1 at 0.5 A g-1 with an impressive rate capability at 10 A g-1, and prominent cycling durability with a capacity retention of 96.4% at a high current density of 10 A g-1 after 10 000 cycles in 6 M KOH in a three-electrode system. Moreover, in 6 M KOH electrolyte, the assembled symmetrical supercapacitor provides a large C of 387.3 F g-1 at 0.5 A g-1. It also presents high specific energy of 34.6 W h kg-1 when the specific power is 200.1 W kg-1 and a praiseworthy specific energy of 8.3 W h kg-1 when the specific power is 4000.0 W kg-1 in 1 M Na2SO4 electrolyte. Thus, this study provides reference and guidance for developing high-performance electrode materials for supercapacitors.

Construction of ZIF@electrospun cellulose nanofiber derived N doped metallic cobalt embedded carbon nanofiber composite as binder-free supercapacitance electrode

In this study, binder-free hybrid supercapacitance electrode based on N, Co co-doped porous carbon polyhedral encapsulated carbon nanofibers composites (N-Co/CNF) was prepared through pyrolyzing cobalt based zeolitic imidazolate frameworks (ZIF-67(Co)) incorporated electrospun cellulose nanofibers. With rational combination of the conductivity provided by cellulose derived CNF, promising porosity provided by CNF and ZIF-67(Co) derived porous carbon and uniformly dispersed metallic cobalt nanoparticles, the N-Co/CNF displayed excellent electrochemical properties. Specifically, the N-Co/CNF pyrolyzed at 800 °C possessed superior electrochemical performance in 1 M H₂SO₄ electrolyte, including a specific capacitance of ~433 F/g and 84% of the capacitance retention after 3000 consecutive charge-discharge cycles. This significantly exceeded the performance of cellulose derived CNF based pure carbonaceous electrode. Therefore, the present study provides a new view on the construction of high performance hybrid supercapacitance electrode which introduces renewable biomass resources like cellulose as both carbonaceous material precursors and conductive binders.

Carbon Monoliths with Hierarchical Porous Structure for All-Vanadium Redox Flow Batteries

Carbon monoliths were tested as electrodes for vanadium redox batteries. The materials were synthesised by a hard-templating route, employing sucrose as carbon precursor and sodium chloride crystals as the hard template. For the preparation process, both sucrose and sodium chloride were ball-milled together and molten into a paste which was hot-pressed to achieve polycondensation of sucrose into a hard monolith. The resultant material was pyrolysed in nitrogen at 750 °C, and then washed to remove the salt by dissolving it in water. Once the porosity was opened, a second pyrolysis step at 900 °C was performed for the complete conversion of the materials into carbon. The products were next characterised in terms of textural properties and composition. Changes in porosity, obtained by varying the proportions of sucrose to sodium chloride in the initial mixture, were correlated with the electrochemical performances of the samples, and a good agreement between capacitive response and microporosity was indeed observed highlighted by an increase in the cyclic voltammetry curve area when the SBET increased. In contrast, the reversibility of vanadium redox reactions measured as a function of the difference between reduction and oxidation potentials was correlated with the accessibility of the active vanadium species to the carbon surface, i.e., was correlated with the macroporosity. The latter was a critical parameter for understanding the differences of energy and voltage efficiencies among the materials, those with larger macropore volumes having the higher efficiencies.

A Simple and Scalable Approach for Fabricating High-Performance Superparamagnetic Natural Cellulose Fibers and Papers

This study introduces a new combined method of wood impregnation and chemical pulping processes leading to the production of superparamagnetic cellulose fibers with a magnetic nanoparticle-free outer surface. First, magnetic wood chips (MWCs) were prepared by in situ synthesizing of magnetite (Fe₃O₄) nanoparticles during the wood impregnation process. The MWCs were then converted into magnetic fibers by kraft pulping. The results showed that the resulting magnetic fibers had an outer surface comparable to that of non-magnetic fibers while showing superparamagnetic behavior. The XRD results confirmed that the in situ synthesized magnetic nanoparticles were magnetite. Papers made from the new type of magnetic cellulose fibers had much more desirable tensile properties, appearance, and printability than papers made from conventional magnetic cellulose fibers, comparable to those made from non-magnetic fibers.

Cellulose Nanofiber Composite with Bimetallic Zeolite Imidazole Framework for Electrochemical Supercapacitors

Cellulose nanofiber (CNF) and hybrid zeolite imidazole framework (HZ) are an emerging biomaterial and a porous carbonous material, respectively. The composite of these two materials could have versatile physiochemical characteristics. A cellulose nanofiber and cobalt-containing zeolite framework-based composite was prepared using an in-situ and eco-friendly chemical method followed by pyrolysis. The composite was comprised of cobalt nanoparticles decorated on highly graphitized N-doped nanoporous carbons (NPC) wrapped with carbon nanotubes (CNTs) produced from the direct carbonization of HZ. By varying the ratio of CNF in the composite, we determined the optimal concentration and characterized the derived samples using sophisticated techniques. Scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS) confirmed the functionalization of CNF in the metallic cobalt-covered N-doped NPC wrapped with CNTs. The CNF–HZNPC composite electrodes show superior electrochemical performance, which is suitable for supercapacitor applications; its specific capacitance is 146 F/g at 1 A/g. Furthermore, the composite electrodes retain a cycling stability of about 90% over 2000 charge–discharge cycles at 10 A/g. The superior electrochemical properties of the cellulose make it a promising candidate for developing electrodes for energy storage applications.

Compressible, anisotropic lamellar cellulose-based carbon aerogels enhanced by carbon dots for superior energy storage and water deionization

Heteroatom-doped carbon materials have received great attention for applications in electrode materials. However, conventional heteroatom-doping methods sacrifice conductivity, stability, and specific surface area (SSA). Here, the carbon quantum dots (CDs) are used as carriers of N, P, O to form electron-rich regions promoting electron transport without decreasing stability and SSA. The CDs promote the formation of graphitic nitrogen in the composite, which effectively reduces their internal resistance by increasing the dielectric constant. Moreover, the orderly growth of ice crystals generates a unique bridged layer structure under bidirectional freeze-casting in a mixture of GO/CDs/microfibrillated cellulose, which gives the composite super-compressibility. Notably, the optimal sample has a 117% increase in specific capacitance. The CDs also improve wettability and thus reduce the charge transfer resistance giving a large desalination capacity of 32.59 mg g^-1 (504 mg L^-1 NaCl). This work illustrates the unique role of CDs in improving the electrochemical performance of composites.

Marigold flower like structured Cu2NiSnS4 electrode for high energy asymmetric solid state supercapacitors

The growth in energy devices and the role of supercapacitors are increasingly important in today’s world. Designing an electrode material for supercapacitors using metals that have high performance, superior structure, are eco-friendly, inexpensive and highly abundant is essentially required for commercialization. In this point of view, quaternary chalcogenide Cu₂NiSnS₄ with fascinating marigold flower like microstructured electrodes are synthesized using different concentrations of citric acid (0, 0.05 M, 0.1 M and 0.2 M) by employing solvothermal method. The electrode materials physicochemical characteristics are deliberated in detail using the basic characterization techniques. The electrochemical studies revealed better electrochemical performances, in particular, Cu₂NiSnS₄@0.1 M-CA electrode revealed high 1029 F/g specific capacitance at 0.5 A/g current density. Further, it retained 78.65% capacity over 5000 cycles. To prove the practical applicability, a full-cell asymmetric solid-state device is fabricated, and it delivered 41.25 Wh/Kg and 750 Wh/Kg energy and power density at 0.5 A/g. The optimum citric acid added Cu₂NiSnS₄ electrode is shown to be a promising candidate for supercapacitor applications.

Nitrogen, Phosphorus and Sulfur Co-Doped Pyrolyzed Bacterial Cellulose Nanofibers for Supercapacitors

Heteroatom doping is an effective way to raise the electrochemical properties of carbon materials. In this paper, a novel electrode material including nitrogen, phosphorus, and sulfur co-doped pyrolyzed bacterial cellulose (N/P/S-PBC) nanofibers was produced. The morphologies, structure characteristics and electrochemical performances of the materials were investigated by Scanning electron microscopy, Fourier transform infrared spectra, X-ray diffraction patterns, X-ray photoelectronic spectroscopy, N₂ sorption analysis and electrochemical measurements. When 3.9 atom% of nitrogen, 1.22 atom% of phosphorus and 0.6 atom% of sulfur co-doped into PBC, the specific capacitance of N/P/S-PBC at 1.0 A/g was 255 F/g and the N/P/S-PBC supercapacitors’ energy density at 1 A/g was 8.48 Wh/kg with a power density of 489.45 W/kg, which were better than those of the N/P-PBC and N/S-PBC supercapacitors. This material may be a very good candidate as the promising electrode materials for high-performance supercapacitors.

Nanoporous Carbon Derived from Green Material by an Ordered Activation Method and Its High Capacitance for Energy Storage

Carbon materials have been widely used as electrode materials for supercapacitors, while the current carbon precursors are mainly derived from fossil fuels. Biomass-derived carbon materials have become new and effective materials for electrodes of supercapacitors due to their sustainability, low pollution potential, and abundant reserves. Herein, we present a new biomass carbon material derived from water hyacinth by a novel activation method (combination of KOH and HNO₃ activation). According to the electrochemical measurements, the material presents an ultrahigh capacitance of 374 F g^-1 (the current density is 1 A g^-1). Furthermore, the material demonstrates excellent rate performance (105 F g^-1 at a higher density of 20 A g^-1) and ideal cycling stability (87.3% capacity retention after 5000 times charge-discharge at 2 A g^-1). When used for a symmetrical supercapacitor device, the material also shows a relatively high capacity of 330 F g^-1 at 1 A g^-1 (a two-electrode system). All measurements suggest the material is an effective and noteworthy material for the electrodes of supercapacitors.