Controlled preparation of interconnected 3D hierarchical porous carbons from bacterial cellulose-based composite monoliths for supercapacitors

Construction of a highly efficient adsorbent for one-step purification of recombinant proteins: Functionalized cellulose-based monolith fabricated via phase separation method

Currently, purification step in the recombinant protein manufacture is still a great challenge and its cost far outweighs those of the upstream process. In this study, a functionalized cellulose-based monolith was constructed as an efficient affinity adsorbent for one-step purification of recombinant proteins. Firstly, the fundamental cellulose monolith (CE monolith) was fabricated based on thermally induced phase separation, followed by being modified with nitrilotriacetic acid anhydride through esterification to give NCE monolith. After chelating with Ni2+, the affinity adsorbent NCE-Ni2+ monolith was obtained, which was demonstrated to possess a hierarchically porous morphology with a relatively high surface area, porosity and compressive strength. The adsorption behavior of NCE-Ni2+ monolith towards β2-microglobulin with 6 N-terminus His-tag (His-β2M) was evaluated through batch and fixed-bed column experiments. The results revealed that NCE-Ni2+ monolith exhibited a relatively fast His-β2M adsorption rate with a maximum adsorption capacity of 329.2 mg/g. The fixed-bed column adsorption implied that NCE-Ni2+ monolith showed high efficiency for His-β2M adsorption. Finally, NCE-Ni2+ monolith was demonstrated to have an excellent His-β2M purification ability from E. coli lysate with exceptional reusability. Therefore, the resultant NCE-Ni2+ monolith had large potential to be used as an efficient adsorbent for recombinant protein purification in practical applications.

Cellulose/GO monolith covered with Pd-Pt bimetallic nanocrystals for continuous-flow catalytic reduction of hexavalent chromium

Cellulose monolith materials have interconnected open porous structures with very high porosity, making them attractive structures for use as support materials in heterogeneous catalysis applications. In this study, we developed a highly efficient and reusable continuous-flow reactor for Cr(VI) remediation by combining the advantageous features of cellulose monoliths with suitable reinforcement techniques. We fabricated a porous monolithic cellulose/graphene oxide (GO) composite with a continuous three-dimensional skeletal framework using the thermally induced phase separation technique. Pd nanocrystals were synthesized in situ on the surface of the composite monolith, and then converted to porous Pd-Pt bimetallic nanocrystals through a galvanic replacement reaction. This approach eliminated the need for additional reductants and stabilizers, making the process simpler and more environmentally friendly. Under carefully optimized conditions, the cellulose/GO/Pd-Pt nanocomposite monolith exhibited outstanding performance in continuous-flow reactions for Cr(VI) reduction, achieving a maximum conversion rate of 98 %. Moreover, the nanocomposite monolith-based heterogeneous catalyst exhibited remarkable long-term stability, maintaining its catalytic activity even after extended periods of storage in the dried state. These findings highlight the potential of cellulose-based composite monoliths as versatile and robust support materials for heterogeneous catalysis.

Cellulose-Based Conductive Materials for Energy and Sensing Applications

Cellulose-based conductive materials (CCMs) have emerged as a promising class of materials with various applications in energy and sensing. This review provides a comprehensive overview of the synthesis methods and properties of CCMs and their applications in batteries, supercapacitors, chemical sensors, biosensors, and mechanical sensors. Derived from renewable resources, cellulose serves as a scaffold for integrating conductive additives such as carbon nanotubes (CNTs), graphene, metal particles, metal-organic frameworks (MOFs), carbides and nitrides of transition metals (MXene), and conductive polymers. This combination results in materials with excellent electrical conductivity while retaining the eco-friendliness and biocompatibility of cellulose. In the field of energy storage, CCMs show great potential for batteries and supercapacitors due to their high surface area, excellent mechanical strength, tunable chemistry, and high porosity. Their flexibility makes them ideal for wearable and flexible electronics, contributing to advances in portable energy storage and electronic integration into various substrates. In addition, CCMs play a key role in sensing applications. Their biocompatibility allows for the development of implantable biosensors and biodegradable environmental sensors to meet the growing demand for health and environmental monitoring. Looking to the future, this review emphasizes the need for scalable synthetic methods, improved mechanical and thermal properties, and exploration of novel cellulose sources and modifications. Continued innovation in CCMs promises to revolutionize sustainable energy storage and sensing technologies, providing environmentally friendly solutions to pressing global challenges.

Recent advances in supramolecular self-assembly derived materials for high-performance supercapacitors

The key preponderance of supramolecular self-assembly strategy is its ability to precisely assemble various functional units at the molecular level through non-covalent bonds to form multifunctional materials. Supramolecular materials have the merits of diverse functional groups, flexible structure, and unique self-healing properties, which make them of great value in the field of energy storage. This paper reviews the latest research progress of the supramolecular self-assembly strategy for the advanced electrode materials and electrolytes for supercapacitors, including supramolecular self-assembly for the preparation of high-performance carbon materials, metal-based materials and conductive polymer materials, and its beneficial effects on the performance of supercapacitors. The preparation of high performance supramolecular polymer electrolytes and their application in flexible wearable devices and high energy density supercapacitors are also discussed in detail. In addition, at the end of this paper, the challenges of the supramolecular self-assembly strategy are summarized and the development of supramolecular-derived materials for supercapacitors is prospected.

Bacterial Nanocellulose from Komagataeibacter Medellinensis in Fique Juice for Activated Carbons Production and Its Application for Supercapacitor Electrodes

This paper presents the results obtained from the chemical activation of bacterial nanocellulose (BCN) using fique juice as a culture medium. BNC activation (BNCA) was carried out with H3PO4 and KOH at activation temperatures between 500 °C to 800 °C. The materials obtained were characterized morphologically, physicochemically, superficially, and electrochemically, using scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), the physisorption of gases N2 and CO2 at 77 K and 273 K, respectively, cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy (EIS). The samples activated with H3PO4 presented specific surface areas (SBET) around 780 m2 g−1, while those activated with KOH values presented specific surface areas between 680 and 893 m2 g−1. The XPS analysis showed that the PXPS percentage on the surface after H3PO4 activation was 11 wt%. The energy storage capacitance values ranged between 97.5 F g−1 and 220 F g−1 by EIS in 1 M H2SO4. The samples with the best electrochemical performance were activated with KOH at 700 °C and 800 °C, mainly due to the high SBET available and the accessibility of the microporosity. The capacitance of BNCAs was mainly improved by electrostatic effects due to the SBET rather than that of pseudocapacitive ones due to the presence of phosphorus heteroatoms.

Characterisation of bacterial nanocellulose and nanostructured carbon produced from crude glycerol by Komagataeibacter sucrofermentans

Bacterial nanocellulose (BNC), which has tunable properties, is a precursor of nanostructured energy storage materials; however, the cost of BNC production is challenging. This study uses crude glycerol from the biodiesel industry as a carbon nutrient and first-time carbonised BNC from K. sucrofermentans that is applied in energy storage. From crude glycerol in static cultivation, 6.4 g L^-1 BNC was produced with a high crystallinity index (85%) and tensile properties in comparison to conventionally used pure carbon substrates. Carbon materials were derived from the BNC retained fibrous and crystalline features with disordered porous structures. The electrochemical properties of the carbon materials have a specific capacitance of 140 F g^-1. This study highlights the valorisation of waste glycerol from the biodiesel industry as a substrate for efficient BNC production and the energy storage potential of carbon derived from BNC as renewable energy materials.

Facile and Scalable Fabrication of High-Performance Microsupercapacitors Based on Laser-Scribed In Situ Heteroatom-Doped Porous Graphene

This study proposes an efficient, facile, and scalable strategy to synthesize in situ heteroatom-doped porous graphene via laser direct writing on the precursor-doped polyimide (PI) film, which is fabricated for the first time through incorporating PI powder and precursors with sodium carboxymethyl cellulose (CMC) binder by a drop-casting and low-temperature drying process. The resulting microsupercapacitors (MSCs) based on the as-prepared heteroatom-doped porous graphene exhibit remarkable capacitive performance. The typical boron-doped MSC prepared on borax-doped polyimide film possesses an ultrahigh areal capacitance of 60.6 mF cm^-2 at 0.08 mA cm^-2, which is approximately 20 times larger than that of undoped MSC. Furthermore, the boron-doped MSC has impressive cycling stability (with the capacitance retention of 96.3% after 20 000 cycles), exceptional mechanical flexibility, tunable capacitance, and voltage output through arbitrary modular serial and parallel integration. Besides, the nitrogen-doped porous graphene with excellent capacitive performance is also prepared by laser direct scribing on the sulfonated melamine-doped polyimide film, demonstrating excellent scalability and generality of this strategy. Hence, one-step laser direct writing on precursor-doped polyimide films can realize in situ heteroatom doping and generation of hierarchical porous graphene electrodes simultaneously, which opens a new avenue for the facile, cost-effective, and scalable fabrication of heteroatom-doped porous graphene, thus promising for MSCs and various flexible and wearable electronics at large-scale production.

Effect of pomelo seed-derived carbon on the performance of supercapacitors

Electrochemical ultracapacitors derived from green and sustainable materials could demonstrate superior energy output and an ultra-long cycle life, which could contribute to next-generation applications. Herein, we utilize pomelo seeds, a bio-waste from pomelo, in high-energy and high-power supercapacitors by a facile low-cost pyrolysis and activation method. The as-synthesized hierarchically porous carbon is surface-engineered with a large quantity of nitrogen and sulfur heteroatoms to give a high specific capacitance of ∼845 F g-1 at 1 A g-1. An ultra-high stability of ∼93.8% even after 10 000 cycles (10 A g-1) is achieved at room temperature. Moreover, a maximum energy density of ∼85 W h kg-1 at a power density of 1.2 kW kg-1 could be achieved in 1.2 V aqueous symmetrical supercapacitors. The results provide new insights that will be of use in the development of high-performance, green supercapacitors for advanced energy storage systems.

A nickel oxide-decorated in situ grown 3-D graphitic forest engrained carbon foam electrode for microbial fuel cells

Carbon foam was used as a substrate for NiO and growing carbon nanofibers. The synthesized NiO-CNF-CF electrode was successfully used as an efficient electrode for a microbial fuel cell.

Nanoarchitectonics of Lotus Seed Derived Nanoporous Carbon Materials for Supercapacitor Applications

Of the available environmentally friendly energy storage devices, supercapacitors are the most promising because of their high energy density, ultra-fast charging-discharging rate, outstanding cycle life, cost-effectiveness, and safety. In this work, nanoporous carbon materials were prepared by applying zinc chloride activation of lotus seed powder from 600 °C to 1000 °C and the electrochemical energy storage (supercapacitance) of the resulting materials in aqueous electrolyte (1M H₂SO₄) are reported. Lotus seed-derived activated carbon materials display hierarchically porous structures comprised of micropore and mesopore architectures, and exhibited excellent supercapacitance performances. The specific surface areas and pore volumes were found in the ranges 1103.0–1316.7 m² g⁻¹ and 0.741–0.887 cm³ g⁻¹, respectively. The specific capacitance of the optimum sample was ca. 317.5 F g⁻¹ at 5 mV s⁻¹ and 272.9 F g⁻¹ at 1 A g⁻¹ accompanied by high capacitance retention of 70.49% at a high potential sweep rate of 500 mV s⁻¹. The electrode also showed good rate capability of 52.1% upon increasing current density from 1 to 50 A g⁻¹ with exceptional cyclic stability of 99.2% after 10,000 cycles demonstrating the excellent prospects for agricultural waste stuffs, such as lotus seed, in the production of the high performance porous carbon materials required for supercapacitor applications.