Interconnected Network Structure Research Articles

Bacterial Cellulose Applications in Electrochemical Energy Storage Devices.

Bacterial cellulose (BC) is produced via the fermentation of various microorganisms. It has an interconnected 3D porous network structure, strong water-locking ability, high mechanical strength, chemical stability, anti-shrinkage properties, renewability, biodegradability, and a low cost. BC-based materials and their derivatives have been utilized to fabricate advanced functional materials for electrochemical energy storage devices and flexible electronics. This review summarizes recent progress in the development of BC-related functional materials for electrochemical energy storage devices. The origin, components, and microstructure of BC are discussed, followed by the advantages of using BC in energy storage applications. Then, BC-related material design strategies in terms of solid electrolytes, binders, and separators, as well as BC-derived carbon nanofibers for electroactive materials are discussed. Finally, a short conclusion and outlook regarding current challenges and future research opportunities related to BC-based advanced functional materials for next-generation energy storage devices suggestions are proposed.

Enhancing aviation safety: Multifunctional graphene nanostructured foams for lightweight fire suppression materials

Fuel tank fires and explosions are the primary causes of military and civilian aircraft losses and have been a major concern for the aviation and defense industries. Passive protection systems with explosion-suppression materials generate a protected environment within fuel tanks before ignition can occur and help prevent catastrophic failures. To minimize these concerns, open-cell reticulated polyurethane foams are extensively used in passive protection systems. However, fire- and explosion-related incidents are still taking place and need to be urgently addressed for aviation safety. This study investigates the effects of graphene nanostructured foams for redesigning the next-generation lightweight fire-retardant materials in aviation. Graphene foams have a unique open-cell morphology with three dimensional (3D) continuous and interconnected network structures and hollow features, which can be suitable for aircraft and defense applications. In this study, mechanical and thermal characterizations tests were conducted on graphene nanostructured foams for a better evaluation. Mechanical loading-unloading studies highlighted their outstanding mechanical energy-absorption capabilities against external loads. The thermogravimetric analysis revealed that the graphene foams provided excellent thermal properties against fire and high-temperature degradation. It was also confirmed that graphene foams uniquely manifested self-extinguishing characteristics during burning tests without catching fire or dripping for secondary fire formations. According to the tube explosion experiments, the graphene foams kept their appearance and strength after blast impacts and elevated explosion temperatures and shock waves. As a result, the proposed multifunctional graphene micro- and nanofoams offer significant potential for the next-generation fire- and explosion-suppression materials in various critical industries, such as aircraft, defense, space, drone, energy, and automotive.

Biomass-Derived Carbon With Large Interlayer Spacing for Anode of Potassium Ion Batteries.

Potassium-ion batteries (PIBs) are emerging as powerful candidate for grid-oriented energy storage owing to their potentially low cost. Carbon is considered the promising anode for PIBs on the basis of its high conductivity and abundant sources. The biggest challenge confronted by carbon anodes lies in insufficient cycle life as well as rate capability, resulting from the limited interlayer spacing of the sp2-hybrid carbon incompatible with the large-radius potassium. Herein, a biomass-derived carbon with a large interlayer spacing of 0.44nm is fabricated via a zinc-assisted pyrolysis synthesis. The unique structure endows the carbon with superior capacity, rate capability, and cycle durability. The large interlayer spacing of carbons can promote fast potassium diffusion and alleviate the volume expansion during potassiation, conferring those rate capabilities and cycleability. The interconnected network structure is also able to shorten both the transport distances of electrons and ions. The demonstration exemplifies an advanced carbon for anodes of PIBs for energy storage applications.

Centimeter‐Scale and Honeycomb‐Like Bismuth Sulfide Film Composed of Triangular Structural Units for Flexible Photodetector

AbstractFilms with honeycomb‐like structures have became ideal network structures for the development of flexible photodetectors due to their superior mechanical stability and merits in large active surface area, high carrier transport efficiency and well light absorption capacity. In this work, a honeycomb‐like Bi2S3 film with centimeter‐scale (2 cm × 2 cm) is synthesized on an ultrathin flexible fluorophlogopite mica substrate, which consists of a well‐stabilized arrangement of triangular unit structures forming an interconnected network structure. Based on the as‐grown honeycomb‐like Bi2S3 film, a flexible photodetector with a broadband response from ultraviolet to infrared is constructed, which displays the highest responsivity (Rλ) of 611.2 mA W−1 and specific detectivity (D*) of 4.77 × 1010 Jones. And at 850 nm light illumination, there is nearly no deterioration in Rλ and D* of the Bi2S3 flexible photodetector after successive multiple bends, benefiting from the excellent structural stability of the triangular honeycomb network structure. Notably, the device maintains excellent detection performance after 1 week of prolonged bending in air without any encapsulation, and its photocurrent can still reach 90.39% of the initial photocurrent. In addition, the device also exhibits favorable durability, cycle stability, as well as high‐definition imaging ability in bending state and after bending recovery.

Flexible and transparent leaf-vein electrodes fabricated by liquid film rupture self-assembly AgNWs for application of heaters and pressure sensors

The leaf veins with hierarchically interconnected network structures have great potential as self-assembly templates for transparent and flexible electrodes. In this paper, a liquid membrane ruptured assisted AgNWs self-assembly method was adopted to obtain conductive veins, which show a low sheet resistance of 3.6Ω/□ and a high transparency of 79 % at a minimal materials waste. The figure of merit of conductive veins was as high as 433Ω-1 and can be further increased by increasing the number of soaking because the light transmittance is nearly immune to the AgNWs layer number. The veins maintained a good electrical conductivity even after bending 10,000 times at a 2 mm radius of curvature and exhibited a good corrosion resistance under harsh conditions. Heaters based on the conductive veins are shown as application examples. A high temperature of 104 °C was achieved at a low voltage of 2 V, which is enough to heat cold water. They still have good heating properties even in the bending state or tensile state. Furthermore, pressure sensors based on the conductive veins were fabricated as examples of wearable devices. The sensor exhibits a high sensitivity of 3.8 kPa−1 in the low-pressure range (0–15 kPa) and 17.4 kPa−1 in the high pressure range (15–50.96 kPa). It can monitor human actions such as finger bending, finger taping, throat swallowing and wrist pulse in real-time, which has promising potential for motion monitoring and information encryption applications.

Aerogel‐Driven Interface Rapid Self‐Gelation Enables Highly Stable Zn Anode

AbstractThe practical application of Zn metal anodes is currently hindered by uncontrolled dendritic growth and water‐induced parasitic reactions that are closely related to the solvation structure and interfacial transport kinetics of Zn2+. Herein, a facile interface self‐gelation strategy is proposed to stabilize Zn anode by introducing ‐OH‐rich silica aerogel (HSA) on Zn anode surface. The unique interconnected network structure and strong hydrophilia of HSA made the aqueous electrolyte near Zn anode gel rapidly and spontaneously, resulting in the formation of a water‐poor gel interface layer. The interface layer can effectively accelerate the desolvation process and reduce water molecule activity near anode surface through hydrogen bonding interaction, thus achieving rapid Zn migration kinetics and alleviating side reactions. In addition, the well‐defined aerogel nanochannels can provide a fast Zn2+ migration path and homogenize Zn2+ flux, enabling rapid and uniform Zn deposition. As a result, the HSA‐modified Zn (HSA@Zn) anode exhibits excellent long‐term cycling stability (over 6000 h at 4 mA cm−2), and the feasibility for practical application of this HSA@Zn anode is further demonstrate in full cells. The aerogel‐driven interface self‐gelation strategy propose in this work provides new insights into the design of advanced Zn anode for aqueous zinc‐ion batteries.

Light-weight flexible symmetric supercapacitors based on magnesium-zinc codoped MnO2 nanostructures on carbon cloth as enhanced-performance binder-free electrodes

Developing advanced flexible supercapacitors with high energy and power density is a critical research goal. One promising approach involves combining manganese dioxide (MnO2) with a three-dimensional carbon substrate. This strategy leads to the creation of supercapacitor electrode materials that exhibit high specific capacitance, stability, and environmental friendliness. However, the challenge lies in addressing the low electrical conductivity of MnO2, which limits the rate of electron transfer. The incorporation of metal ions enhances the conductivity of manganese oxide, resulting in a significant increase in lattice defects. These defects create abundant active sites for energy storage. In this study, we developed flexible electrodes based on magnesium-doped MnO2, zinc-doped MnO2, and magnesium-zinc codoped MnO2 nanostructures deposited on carbon cloth (CC) via a one-step hydrothermal method. The supercapacitive behavior of these electrodes was investigated using CV and GCD measurements. The as-prepared electrodes exhibit good electrical conductivity, and their interconnected network structure, composed of sponge-shaped nanostructure layers, results in a large specific surface area. This network also facilitates efficient pathways for effective electron transport. The optimized Mg-Zn codoped MnO2@CC sample exhibits a high capacitance of 79.9 mF/cm² at 0.7 mA/cm² and good rate performance, reaching around 46.59 mF/cm² up to 1.5 mA/cm² in the three-electrode system. Notably, the areal capacitance values calculated from the CV curves for all Mg-Zn codoped MnO2@CC electrodes surpass those of Mg-doped MnO2@CC and Zn-doped MnO2@CC. A flexible symmetric supercapacitor assembled using the best Mg-Zn codoped MnO2@CC as both positive and negative electrodes and PVA-Na2SO4 gel electrolyte delivers a desirable energy density of 0.196 mWh/cm2 at 2.38 mW/cm2. Furthermore, this fabricated supercapacitor demonstrates a broad voltage window of 2.25 V and remarkable cycling stability, retaining 83 % of its initial performance after 4000 charge-discharge cycles.

Incorporation of nitrogen and oxygen in carbon: A highly tuned electrochemistry with facile synthesis and its influence on optical and electrode performance in supercapacitors

A new approach for synthesizing heteroatom-doped carbon nanostructures has been developed, in which nitrogen and oxygen have been effectively infused into the graphitic core using the required precursors. The heteroatoms incorporated into the carbon matrix and their corresponding structural features are examined. The observed X-ray diffraction pattern reveals the presence of amorphous carbon forms that resemble carbon nitride in their structure. The presence of additional N–O and C–O bonds gives strong evidence of a graphitic structure with oxygen and nitrogen incorporation, as shown by the Fourier transform-infrared peaks. The X-ray photoelectron spectroscopy analysis reveals important information regarding the bond formation in the graphitic core of the sample. The study focused on examining the porous and intricately interconnected network structures, showcasing a variety of particle morphologies, and was carried out using scanning electron and transmission electron microscopy. The lattice defects are investigated using transmission electron microscopy-high angle annular dark field technique to explore the surface morphology. The influence of incorporated O and N in carbon structure drastically reduced the electron density of the graphitic core. As a result, the absorption bands observed were around 300–400 nm, showing the semiconductors' absorption characteristics. Three-electrode electrochemical systems are fabricated with working electrodes based on COx and CNx materials. The COx and CNx-modified electrodes were meticulously tested for their performance in supercapacitor applications. The COx samples exhibit a significant specific capacity value of 439.20 C g−1 under a low current density of 4 A g−1. The CNx samples demonstrate a specific capacity of 420.00 C g−1 under 4 A g−1 current density.

Effects of the Amylose/Amylopectin Ratio of Starch on Borax-Crosslinked Hydrogels.

Herein, we simultaneously prepared borax-crosslinked starch-based hydrogels with enhanced mechanical properties and self-healing ability via a simple one-pot method. The focus of this work is to study the effects of the amylose/amylopectin ratio of starch on the grafting reactions and the performance of the resulting borax-crosslinked hydrogels. An increase in the amylose/ amylopectin ratio increased the gel fraction and grafting ratio but decreased the swelling ratio and pore diameter. Compared with hydrogels prepared from low-amylose starches, hydrogels prepared from high-amylose starches showed pronouncedly increased network strength, and the maximum storage modulus increased by 8.54 times because unbranched amylose offered more hydroxyl groups to form dynamic borate ester bonds with borate ions and intermolecular hydrogen bonds, leading to an enhanced crosslink density. In addition, all the hydrogels exhibited a uniformly interconnected network structure. Furthermore, owing to the dynamic borate ester bonds and hydrogen bonds, the hydrogel exhibited excellent recovery behavior under continuous step strain, and it also showed thermal responsiveness.

Dynamic Covalent Boronic-Acid-Functionalized Alginate/PVA Hydrogels for pH and Shear-Responsive Drug Delivery.

Herein, we investigated hydrogels composed of boronic-acid-functionalized alginate and blended with polyvinyl alcohol (PVA) of different molecular weights to control the release of metoclopramide hydrochloride as a function of pH and shear stress. The functionalization of alginate introduced dynamic covalent bonding and pH-responsive properties that can modulate network connectivity. The study investigated the viscoelastic properties of the hydrogels, their drug release profiles, and their responsiveness to changes in pH and shear forces. The results showed that a higher PVA molecular weight and alkaline pH conditions increased hydrogel viscosity and stiffness due to a more stable and interconnected network structure than acidic pH. Metoclopramide release revealed that the hydrogels exhibited pH-responsive drug release behavior. The drug was more readily released under acidic conditions due to the instability of sp2-hybridized boronate ester bonds. The influence of shear forces on the release of metoclopramide was also investigated at shear rates of 1, 10, and 100 s-1, revealing their effect on matrix stiffening. Research shows that AlgBA/PVA hydrogels have unique properties, such as dynamic covalent bonding, that make them sensitive to external mechanical forces. This sensitivity makes them ideal for applications where physiological conditions trigger drug release.

Synergistic structural engineering of 3D printed matchable electrodes for long-life rechargeable nickel–bismuth batteries

Aqueous rechargeable alkaline batteries have attracted increasing attention due to their reliable safety, low cost and high electrochemical potential. However, it remains challenging to construct remarkable rechargeable batteries with desirable electrode architectures and optimized electrochemical mechanisms. Herein, 3D printed high-loading bismuth-based anodes with synergistic enhancement of three-dimensional interconnection network structure and oxygen vacancies is achieved, for which intrinsic battery charge storage mechanism is in-depth unveiled. The synergistic structural engineering significantly enhances the overall charge carrier transport of 3D printed nickel-bismuth batteries, as evidenced by the conductivity of a single-wired electrode, enabling nickel-bismuth batteries to achieve a high areal capacity of 0.17 mA h cm−2 at 6 mA cm−2, a high energy density of 97.92 μWh cm−2 and a power density of 6.41 mW cm−2. Moreover, superior cycling stability is obtained. Ex situ characterization results reveal that Bi2O2.33 undergoes a phase transition after the initial charge and discharge, while the subsequent cycles rely on the reversible phase transition mechanism between Bi and Bi2O3 for basic charge storage. The exceptional performance and revealed mechanism of 3D printed batteries offer novel ideas and understanding for constructing future rechargeable nickel-bismuth batteries with state-of-the-art behaviors.

Form-Stable phase change composites with high thermal conductivity and enthalpy enabled by Graphene/Carbon nanotubes aerogel skeleton for thermal energy storage

Thermal energy storage offers enormous potential in energy utilization and phase change materials (PCMs) plays a crucial role in energy management. However, the intrinsically low thermal conductivity, easy liquid leakage and low latent heat of PCMs are great challenges for enabling their use. Herein, a novel method was developed to solve the drawbacks of PCMs by encapsulation of reduced graphene oxide/carbon nanotubes hybrid aerogels (rGCA). The rGCA with interconnected network structures was prepared through chemical reduction and self-assembly under atmospheric pressure drying using carbon nanotubes as the supporting skeleton. The rGCA as 3D scaffold could accommodate paraffin wax (PW) to obtain PW/rGCA phase change composites, which showed excellent shape stability even heating above melting point of PW, and no obvious liquid leakage occurred. PW/rGCA exhibited excellent phase change ability with high phase change enthalpy of 236.7 J/g, which was close to that of pure PW. Moreover, the phase change enthalpy of PW/rGCA still maintained 96.5 % of initial PW even after 100 cycles, revealing the good long-term thermal and chemical stability. The pre-constructed continuous 3D thermally conductive network enabled the thermal conductivity of PW/rGCA up to 1.897 W/mK, much higher than that of pure PW and PW/rGA. The higher thermal diffusion of PW/rGCA resulted in the faster temperature change rate, exhibiting highly reversible thermal behavior of absorbing and releasing heat energy. Furthermore, crosslinked natural rubber (NR) chains were introduced into rGCA to enhance the mechanical property and elasticity, and PW/NR@rGCA composites showed excellent shape stability, good phase change ability and high thermal conductivity, revealing promising applications in energy storage.

Mechanism of Interconnected Pore Formation in High Internal Phase Emulsion-Templated Polymer.

High internal phase emulsion-templated polymer, named polyHIPE, has received widespread attention due to its great potential applications in many fields, such as separation, adsorption, heterogeneous catalysis, and sound absorption. The broad applicability is largely dependent on its adjustable opening structure. However, the question of why polyHIPE has an interconnected pore network structure is still to be discussed. Herein, different types (w/o, o/w, and o/o) of HIPEs are prepared and subsequently detected with laser scanning confocal microscopy (LSCM), and the polyHIPEs obtained by curing the HIPEs are characterized by SEM. The observations suggest that the interconnected pore formation is primarily due to the presence of the surfactant-rich phase in the film between the neighboring droplets in HIPE. The interconnected pores are generated by removal of the surfactant-rich domains in the postcuring procedure, and their sizes would be enlarged if the solubility of the surfactant in the continuous phase decreases in the curing stage.

Preparation of β-cyclodextrin/PVDF composite films for efficient adsorption of Cu2+

Water pollution issues are becoming more and more serious, particularly those caused by heavy metal ions. In this paper, β-cyclodextrin (β-CD) and polyvinylidene fluoride (PVDF) were chosen to prepare composite films by electrospinning technology. The microstructure, crystalline phases, mechanical properties, porosity, and adsorption performance of β-CD/PVDF composite films were analyzed. The results show that the β-CD/PVDF composite fibers were smooth and randomly deposited to form an interconnected three-dimensional network structure. The diameter of the β-CD/PVDF composite fibers ranged from 0.22 to 0.33 μm, and the fiber diameter distribution was uniform. The maximum porosity was 79.56% when the content of β-CD was 2%. After adding the β-CD, the tensile strength increased to 13.33 MPa and the elongation at break increased to 14.20% as well. With the β-CD content increasing, the adsorption capacity of the β-CD/PVDF composite films for Cu2+ increased to 182.65 mg g−1. In addition, the second-order kinetic model was suitable to describe the adsorption process, and the chemical adsorption was the predominant mechanism of the adsorption process due to the presence of β-CD. The results suggest that the β-CD/PVDF composite films may be a potential adsorbent for Cu2+ adsorption.

Unleashing the power of 3D Ti3C2Tx: A breakthrough in electrochemical energy storage

The tendency of Ti3C2Tx nanosheets to be stacked makes it challenging to immobilize the active material, thus limiting the performance of the storage device. Integrating two-dimensional Ti3C2Tx into three-dimensional (3D) structures is considered one of the important yet challenging approaches to realize ultra-high-performance supercapacitors. In this study, we report the preparation of Ti3C2Tx into a 3D network interconnection structure using the sacrificial template method, with polydopamine (PDA) serving as a coating material for encapsulation. Subsequently, the Ti3C2Tx/PDA composite is combined with NiS as an electrode material. The 3D Ti3C2Tx structure effectively hinders the stacking of Ti3C2Tx, while the –OH groups on the surface of PDA form non-covalent interactions with the functional groups of 3D Ti3C2Tx, preventing its oxidation and accelerating electron transfer. The nitrogen atom in PDA can anchor Ni-S to avoid its detachment, which leads to better electrochemical properties of the prepared composites. Ni-S/3D Ti3C2Tx@PDA as an electrode material had a high specific capacitance of 281.8 mAh/g (1 A/g). The asymmetric supercapacitor using Ni-S/3D Ti3C2Tx @PDA as the anode material achieved a high energy density of 35.5 W kg−1 at 1600 W kg−1 power density, and excellent cycling stability, possessing 98.83 % cycle retention and 84.98 % capacity efficiency at 3 A/g for 10,000 cycles. In summary, it can be seen that Ni-S/3D Ti3C2Tx @PDA materials have great potential for development in supercapacitors.

Reusable multifunctional interlayer for dendrite-free and ultrastable zinc anodes via regulating zinc-ion transport and inhibiting hydrogen evolution

The practical application of zinc anodes in aqueous zinc-ion batteries (ZIBs) is hindered due to uncontrollable dendritic Zn deposition and side reactions. Herein, a reusable interlayer constructed from Sn nanoparticles-modified polyhydroxy semi-carbonized bacterial cellulose (Sn@PHCBC) with three-dimensional interconnected network structure is proposed to achieve sustainable and smooth regulation of zinc anode. The suppression of dendrites is primarily attributed to the uniform Zn ions flux constructed by reversible Sn-Zn alloy nanoparticles channel, as well as the targeted transport and rapid desolvation of hydrated zinc ions through hydroxyl groups of PHCBC. Additionally, the abundant high overpotential Sn nanoparticles anchored in Sn@PHCBC interlayer effectively inhibit the hydrogen evolution reaction and minimize the formation of byproducts. As a result, the Zn||Zn symmetrical cell assembled with Sn@PHCBC interlayer demonstrates highly reversible electroplating/stripping behavior with an extended lifespan of 800 h at high current densities of 10 mA cm−2 and 10 mAh cm−2. Besides, after 1000 cycles of MnO2||Sn@PHCBC//Zn full cell, the Sn@PHCBC interlayer can still be reused with nearly 100 % coulombic efficiency after simple treatment. The rational design in this work provides a feasible solution for high-performance ZIBs and promote the development of advanced energy storage devices reutilization.

Cyanogel-Induced Facile Synthesis of Palladium Hydride for Electrocatalytic Oxygen Reduction.

Palladium hydride (PdHx) is one of the well-known electrocatalytic materials, yet its synthesis is still a challenge through an energy-efficient and straightforward method. Herein, we propose a new and facile cyanogel-assisted synthesis strategy for the preparation of PdH0.649 at a mild environment with NaBH4 as the hydrogen source. Unlike traditional inorganic Pd precursors, the unique Pd-CN-Pd bridge in Pdx[Pd(CN)4]y ⋅ aH2O cyanogel offers more favourable spatial sites for insertion of H atoms. The characteristic three-dimensional backbone of cyanogel also acts as a support scaffold resulting in the interconnected network structure of PdH0.649. Due to the incorporation of H atoms and interconnected network structure, the PdH0.649 achieves a high half-wave potential of 0.932 V, a high onset potential of 1.062 V, and a low activation energy, as well as a long-term lifetime for oxygen reduction reaction. Theoretical calculation demonstrates a downshift of the d-band centre of Pd in PdH0.649 owing to the dominant Pd-H incorporation that weakens the binding energies of the *OH intermediate species. Zn-air batteries (ZAB) based on PdH0.649 exhibits high power density, competitive open circuit voltage, and good stability, exceeding that of commercial Pt black. This work not only opens up a new avenue for the development of high-efficiency Pt-free catalysts but also provides an original approach and insight into the synthesis of PdHx.

Earthworm-Inspired Ultra-Durable Sliding Triboelectric Nanogenerator with Bionic Self-Replenishing Lubricating Property for Wind Energy Harvesting and Self-Powered Intelligent Sports Monitoring.

Triboelectric nanogenerators (TENGs), a promising strategy for harvesting distributed low-quality power sources, face inevitable bottlenecks regarding long-term abrasion and poor durability. Herein, both issues are addressed by selecting an earthworm-inspired self-replenishing bionic film (ERB) as the tribo-material of sliding-freestanding TENGs (SF-TENGs), it consists of an interconnected 3D porous network structure capable of storing and releasing lubricant under cyclic mechanical stimuli. Thanks to the superiority of self-replenishing property, there is no need for periodic replenishment and accurate content control of lubricant over the interfacial-lubricating SF-TENGs based on dense tribo-layers. Additionally, an SF-TENG based on ERB film (ERB-TENG) demonstrates remarkable output stability with only a slight attenuation of 1% after continuous operation for 100000 cycles. Moreover, the ERB-TENG displays a distinguished anti-wear property, exhibiting no distinct abrasion with an ultra-low coefficient of friction (0.077) and maintaining output stability over a prolonged period of 35 days. Furthermore, integration with an energy management circuit enables the ERB-TENG to achieve a 39-fold boost in charging speed. This work proposes a creative approach to enhance the durability and extend the lifespan of TENG devices, which is also successfully applied to wind energy harvesting and intelligent sports monitoring.

Production and Characterization of Bacterial Cellulose Synthesized by Komagataeibacter sp. Isolated from Rotten Coconut Pulp

Bacterial cellulose is a naturally occurring polysaccharide that is produced by acetic acid bacteria. It has become increasingly popular due to its numerous biotechnological applications. Bacterial cellulose is free from contaminants that are often associated with plant cellulose. This study aims at isolation of bacterial cellulose producing microbial strains from rotten fruits. The selected bacterial cellulose producer was identified using biochemical tests, including biochemical, carbohydrate fermentation, morphology, gram staining and 16S rRNA sequence analysis. Furthermore, several different media were evaluated for higher production of cellulose. The produced cellulose sheets were washed, purified and characterized using various analytical techniques, including FTIR, XRD and SEM analysis. A potential high bacterial cellulose yielding microbial strain was isolated from coconut pulp waste and identified as Komagataeibacter saccharivorans strain BC-C1 using 16S rRNA sequencing. Effect of media components on bacterial cellulose production was studied. The isolate yielded 0.52 g/100 mL with Hestrin-Schramm (HS) culture media (designated as M1) and 1.10 g/100 mL in M5 media. The physico-chemical characterization demonstrated that produced bacterial cellulose sheets show characteristics IR bands and three-dimensional fibrillar interconnected network structure. The study revealed that isolated Komagataeibacter saccharivorans strain BC-C1 can be utilized for large scale production of bacterial cellulose.

Highly stable Ag-doped Cu2O immobilized cellulose-derived carbon beads with enhanced visible-light photocatalytic degradation of levofloxacin

Ag-doped Cu2O immobilized carbon beads (Ag/Cu2O@CB) based composite photocatalysts have been prepared for the removal of levofloxacin, an antibiotic, from water. The photocatalysts were prepared by the processes of chemical reduction and in-situ solid-phase precipitation. The composite photocatalyst was characterized by a porous and interconnected network structure. Ag nanoparticles were deposited on Cu2O particles to develop a metal-based semiconductor to increase the catalytic efficiency of the system and the separation efficiency of the photogenerated carriers. Cellulose-derived carbon beads (CBs) can also be used as electron storage libraries which can capture electrons released from the conduction band of Cu2O. The results revealed that the maximum catalytic degradation efficiency of the composite photocatalyst for the antibiotic levofloxacin was 99.02 %. The Langmuir–Hinshelwood model was used to study the reaction kinetics, and the process of photodegradation followed first-order kinetics. The maximum apparent rate was recorded to be 0.0906 min-1. The mass spectrometry technique showed that levofloxacin degraded into carbon dioxide and water in the presence of the photocatalyst. The results revealed that the easy-to-produce photocatalyst was stable and efficient in levofloxacin removing.