Chemical Activation Research Articles

Mechanism of Antimicrobial Activities of Medicinal Plants Extracts, From Traditional Knowledge to Scientific Insights

Background: Over the years, the medicinal properties of plants have been recognized as important sources of active ingredients in herbal medicine. In particular, plant-derived active ingredients have been used in microbial natural products long before the advent of modern medicine. Discussion: Since ancient times, the potency of medicinal plant products has been linked to the chemical, biochemical and synthetic activities of the plant product. Therefore, with the advancement of modern science in molecular and cellular biology, analytical chemistry and pharmaceuticals, the unique properties of these plant products are used to exploit the chemical and structural diversity and diversity. of the biology of this type of fruit in relation to their medicinal properties. Conclusion: New molecules are of interest to drug designers who are interested in modifying the chemical entities or structural parameters of natural products to produce new molecules that can be made into effective medicine.

Synthesis of Activated Charcoal from Coconut Shell for the Removal of Crude Oil Spill

Crude oil spills have devastating effects on the environment, particularly aquatic ecosystems. The purpose of the present research is to determine whether dry coconut shells can be used as raw materials to make activated charcoal (AC) via pyrolysis and whether they can be utilized as natural sorbents to clean up crude oil spills. The UV-Vis spectrum of the synthesized CSAC shows distinct peaks at 230 and 260 nm, whereas the activated charcoal exhibits peaks at 231 and 261 nm. The FTIR spectra of the synthesized CSAC reveal a medium broad absorption peak at 3307.2 cm⁻¹, while the raw coconut shell's FTIR spectra show a medium sharp peak at 2945.3 cm⁻¹. The SEM images highlight the unique structural properties of CSAC, showcasing high porosity, varied pore sizes, rough surface topography, and the presence of micropores and mesopores. The chemical activation significantly increased the hydrophobicity of the adsorbent, creating CSAC with a much better adsorption capacity for crude oil removal, having a maximum adsorption capacity of 4840.0 mg/g and the highest percentage of crude oil removal at 99.9985%, as proven by batch experiments for different adsorbent dosages. The batch experimental results indicated that the percentage of crude oil removal increased with an increase in adsorbent dosage and contact time. Based on the correlation coefficients (R²) values (close to unity), it was generally observed that the plots match the Freundlich isotherm better than the Langmuir isotherm model. These findings have made the synthetic CSAC an attractive, useful, and environmentally friendly adsorbent.

Chemical Composition, Antimicrobial and Antioxidant Activities of Broccoli, Kale, and Cauliflower Extracts.

The brassicas have the potential to prevent chronic non-communicable diseases and it is proposed to evaluate the chemical composition, antioxidant and antimicrobial potential of broccoli, cabbage and extracts. The extracts were prepared and characterized and the antioxidant potential was evaluated against three radicals while the antimicrobial potential was analyzed using three techniques against four bacteria. The extracts have glucosinolates and phenolic compounds in their composition, and effectively inhibit the 2,2-diphenyl-1-picrylhydrazyl radical. The extracts of broccoli and cauliflower showed an inhibitory effect against hydroxyl radicals and nitric oxide. Disk diffusion showed that broccoli and cauliflower extract were active against three bacteria, while kale extract showed active halos for Gram-negative bacteria. Kale extract had an inhibitory effect Gram-positive bacteria, cauliflower extract inhibited the growth of Staphylococcus aureus. The cauliflower extract thus had a higher concentration of phenols, a strong antioxidant activity and promising results at a concentration of 100mg/mL against S. aureus.

Essential oils of Plumeria alba L. and Plumeria rubra L. growing in Egypt: GC/MS analysis, molecular dynamics and in-vitro anti-cholinesterase activity

AimEssential oils (EOs) from Plumeria species exhibit noteworthy chemical compositions and diverse biological activities, rendering them valuable constituents for use in medicine, cosmetics, and perfumery. Our aim is to investigate the chemical profiles of P. alba L. and P. rubra L. cultivated in Egypt as biologically active crops. MethodsThe EOs of the flowers of P. alba and P. rubra cultivated in Egypt were prepared by steam distillation and headspace and analyzed by GC/MS. Principal components analysis (PCA) was used to assess the correlation between the chemical composition of the EOs and those reported for EOs of Plumeria species in other countries. ResultsThe score plot revealed a notable difference in the components of EOs prepared by steam distillated and headspace. Geranyl benzoate (27.55 %) was the major compound identified in steam distillated sample of P. alba and linalool (32.52 %) was the major in that prepared by headspace. On the other hand, 1-heptacosanol (23.86 %) was the major compound in the steam distillated sample of P. rubra and 2-methyl-butyl aldoxime (36.38 %) was the major compound in that prepared by headspace. Both EOs demonstrated in-vitro inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Docking study revealed that aromatic compounds have better fitting, while aliphatic compounds have better stability with lower docking interaction energy, and geranyl benzoate showed docking results and binding mode similar to that of the ligands of both enzymes; its stability after docking was confirmed by molecular dynamics. ConclusionEOs from Plumeria species are highly recommended for developing natural and effective aromatherapy products for Alzheimer’s disease.

A Review on Chemical Structures and Biological Activities of Dopamine Derivatives from Medicinal Insects.

Medicinal insects play an important role in the treatment of refractory diseases due to their unique and rich pharmacological activities. However, compared to plants, microorganisms, and marine organisms, medicinal insects have been largely ignored. Some small molecules isolated from insects are known to have defensive effects, but their majority roles remain unknown. In-depth research on the small molecules of medicinal insects has been conducted in recent years. Then alkaloids, dopamine derivatives, nucleoside derivatives, and other components are obtained. Among them, dopamine derivatives are a unique class of components from medicinal insects. Thus, we present a comprehensive overview of chemical structures and biological activities of dopamine derivatives from some medicinal insects, which will bring more attention to other researchers for further chemical and biological investigations on the unique dopamine derivatives as well as medicinal insects.

Assessing chemical composition and biological activity in Eucryphia cordifolia Cav. (Cunoniaceae): A study applying the ecological niche centrality hypothesis

Eucryphia cordifolia Cav., native to the forests of southern Chile, was used for medicinal purposes by the Mapuche people in ancient times. However, there are no recent studies on the biological properties of its leaves in their natural habitat. This study assessed how the location of E. cordifolia populations in their ecological niche (center or periphery) impacts the chemical composition, antioxidant activity, and antimicrobial properties of leaf extracts.Ultra-liquid chromatography coupled to mass spectrometry was used to characterize the chemical composition of the extracts (UHPLC-QTOF-MS). The antioxidant activity was assessed through DPPH, ABTS, and ORAC assays, and the total polyphenol content was determined using the Folin-Ciocalteu method. Antimicrobial activity was analyzed using methods such as agar diffusion, determination of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and biofilm formation assay. The leaves extract contained 28 identified compounds, including flavonols, flavones, flavanols, and other bioactive compounds. The peripheral population exhibited higher antioxidant values based on ABTS and ORAC methods in autumn and spring, and higher total polyphenol levels only in autumn. The E. cordifolia extracts significantly inhibited the growth of E. coli, S. aureus, and P. aeruginosa, with minimum bactericidal concentration values ranging between 1.2-5.3 mg/mL, lower than in other studies. Additionally, the peripheral population displayed greater inhibition of C. glabrata biofilm formation compared to the centroid and intermediate populations in both summer and autumn. In conclusion, this first comprehensive investigation of E. cordifolia reveals that its leaves are a valuable source of bioactive compounds with biotechnological potential.

Lignocellulosic Biomass‐Derived Graphene: Fabrication, Challenges and Its Potential for Hydrogen Storage Application

ABSTRACTThis review explores the utilization of lignocellulosic biomass (LCB) waste in the fabrication of graphene and its applications in hydrogen storage. Several LCB wastes, such as rice straws, coconut shells, wheat straws, and sugarcane bagasse, along with the methodology used and the characteristics of the final graphene, have been discussed in detail. It was found that the coconut shells produced crumpled multilayered graphene, rice husks (RHs) provided a mix of graphene layers and amorphous carbon, wheat straw yielded few‐layered graphene, and sugarcane bagasse contributed to different graphene‐like materials. This review has also focused on the various synthesis processes, such as carbonization, hydrothermal carbonization (HTC), chemical activation, pyrolysis, chemical vapor deposition (CVD), and Hummers' method for graphene fabrication from LCB waste, along with their advantages and disadvantages, for a better understanding. Various results have been discussed exploring the use of lignocellulosic biomass‐derived graphene (LCB‐G) and its various modified forms for hydrogen storage applications. Various challenges in graphene fabrication from LCB, such as low yield, product quality, scalability, use of expensive synthesis methods, and toxic chemicals, along with some potential solutions, have been mentioned. Finally, the review concludes with insights into the future of LCB‐G and its role in hydrogen storage while identifying some gaps, such as scalability and product quality, for further research and development.

Chitosan-derived activated carbon/chitosan composite beads for adsorptive removal of methylene blue and acid orange 7 dyes

In this study, a chitosan/activated carbon composite was developed for the sustainable removal of dye pollutants from activated carbon derived from chitosan. First, chitosan was converted into chitosan-derived activated carbon (C-AC) with a large Brunauer-Emmett-Teller (BET) surface area of 2428 m2/g through carbonization using a potassium hydroxide (KOH) chemical activator. To enable simple separation from contaminated water and sustainable use in the adsorption process, the generated C-AC was incorporated into a bead-type, stable three-dimensional chitosan polymer network structure. The prepared C-AC-incorporated chitosan beads showed excellent adsorption capacity for the anionic acid orange 7 (AO) (511.38 mg/g) and the cationic methylene blue (MB) (413.08 mg/g). In addition, it maintained structural stability even in various pH environments and could be easily separated from contaminated water. The C-AC-incorporated chitosan beads showed excellent reusability and durability, maintaining at least 82% and 86% removal efficiencies for AO and MB dyes even after five reuses. This study suggests the potential use of chitosan as an eco-friendly adsorbent that can be utilized simultaneously as an activated carbon precursor and as a matrix for robust bead-like polymer composites.

Adsorption of Nefazodone on single-wall carbon nanotube as an antidepressant drug delivery: A DFT study

Nefazodone, a derivative of triazolones, belongs to a group of heterocyclic aromatic compounds. It is used as an antidepressant for treating depression, including major depressive disorder. Unlike other antidepressant groups such as selective serotonin reuptake inhibitors, tricyclic antidepressants, or monoamine oxidase inhibitors, Nefazodone does not share chemical similarities. Recent research has focused on studying the reactivity and chemical structure influenced by Nefazodone's medicinal features in the drug's adsorption process on single-wall Carbon Nanotube (CNT) as an adsorbent in the gas phase using density functional theory (DFT), Becke, 3-parameter, Lee–Yang–Parr (B3LYP) 6-311+G(d,p) basis set (DFT/B3LYP/6-311+G(d,p)). The effect of electronegative atoms and phenyl groups on the adsorption of Nefazodone on CNT has been studied by calculating the adsorption energy for all active sites. On the other hand, thermodynamic values, such as Gibbs free energy (−4873.09 kJ), Enthalpy (−4872.83 kJ), and Entropy (903.09 J/mol.kelvin), as well as thermodynamic capacity (497.45 J/mol.kelvin), were calculated to show the reactivity of Nefazodone. The stability and reactivity were examined through the energies of the highest occupied molecular orbital (HOMO) (−5.53 eV) and lowest unoccupied molecular orbital (LUMO) (−0.58 eV) of Nefazodone, highlighting ten regions with chemical activity, all of which are thermodynamically stable. Some Electronic parameters such as chemical potential (µ), electronegativity (χ), softness (σ), hardness (η), and electrophilicity index (ω) were calculated. The comparison of chemical potential values between Nefazodone(−3.05 eV) and the more stable complex (−3.81 eV) illustrates the more reactivity for the complex. This suggests that Nefazodone can be transferred to biological systems through such an adsorption mechanism.

Comparative analysis of nutritional value and antioxidant activity in sweet and bitter almonds

In this study, four cultivars of almonds including bitter and sweet almonds from the northern regions of Morocco have been studied in terms of chemical composition, bioactive content, and antioxidant activity. Our research revealed that almonds are rich in minerals, and they displayed low levels of primary oxidation by-products and excellent stability. The fatty acid composition was dominated by oleic and linoleic acids, with slight variations between regions and almond cultivars. The analyses of unsaponifiable fraction revealed that the sterol component of almond oil was mainly composed by β-sitosterol and Δ-5-avenosterol (with regional differences), meanwhile α-tocopherol was the predominant among tocopherols. Furthermore, a significant presence of phenolic compounds was observed, particularly in Al Hoceima Beldi sweet almonds, with a gallic acid equivalent of 47.15 mg GAE/g in methanol extract and a total tocopherol content of 558.53 mg/kg. These results highlighted the strong antioxidant potential of Al Hoceima Beldi sweet almond oil, which showed good antioxidant activity for 2,2-Diphenyl-1-picrylhydrazyl (DPPH) with an IC50 value of 63.47 μg/mL and a high concentration of samples for 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (19.48 mg TE/g extract). In conclusion, the research supports the cultivation and consumption of these sweet almond cultivars in recognition of their significant contribution to human well-being. Bitter almonds have medicinal benefits but are toxic and unsafe for consumption.

Chemical composition, biological activities and product development of Gastrodia elata: a review

Chemical composition, biological activities and product development of Gastrodia elata: a review

Chemical Content and Cytotoxic Activity on Various Cancer Cell Lines of Chaga (Inonotus obliquus) Growing on Betula pendula and Betula pubescens.

Chaga mushroom (Inonotus obliquus) is a pathogenic fungus that grows mostly on birch species (Betula pendula Roth and B. pubescens Ehrh.) and has traditionally been used as an anticancer medicine. This study aimed to compare the chemical composition and cytotoxic activity of chagas growing on both Betula spp. on various cancer cell lines. The freeze-dried extracts contained triterpenes inotodiol, lanosterol betulin, and betulinic acid typical to conks growing on Betula species. The cytotoxic activity of chaga growing on Betula pendula and B. pubescens 80% ethanolic extracts against 31 human cancer cell lines was evaluated by a sulforhodamine B assay. Chaga extract showed moderate activity against all cancer cell lines examined; it did not result in high cytotoxicity (IC50 ≤ 20 µg/mL). The strongest inhibitions were observed with chaga (growing on B. pendula) extract on the HepG2 and CAL-62 cell line and with chaga (from B. pubescens) extract on the HepG2 cell line, with IC50 values of 37.71, 43.30, and 49.99 μg/mL, respectively. The chaga extracts from B. pendula exert somewhat stronger effects on most cancer cell lines studied than B. pubescens extracts, which can be attributed to a higher content of inotodiol in B. pendula extracts. This study highlights the potential of chaga as a source of bioactive compounds with selective anticancer properties. To the best of our knowledge, this study is the first investigation of the chemical composition of I. obliquus parasitizing on B. pubescens.

Repurposing Suan-Zao-Ren-Tang as anticancer agents in apoptotic sensitization against non-small cell lung cancer cell lines through amplification of spindle assembly checkpoint activation

Treatment of non-small cell lung cancer (NSCLC) is a high unmet medical need. We repurposed Suan-Zao-Ren-Tang (SZRT), a widely used traditional Chinese medicine in alleviating insomnia, to sensitize vinorelbine-induced anti-NSCLC effect and have unveiled the underlying mechanism. B7E2, the partial purified extract from SZRT, was used through bioactivity-guided fractionation based on anti-proliferative activity in NSCLC cell lines A549 and NCI-H460. Three batches of B7E2 and their individual components were prepared for the examination of components and bioactivity and mechanistic study. B7E2 alone had no cytotoxic effect but its combination with vinorelbine displayed a synergistic activity in killing NSCLC cells. Apoptotic sensitization was verified by a remarkable increase of caspase activation and phosphorylation of Bcl-2 and Bcl-xL. Combination treatment prolonged mitotic arrest and induced a substantial activation of spindle assembly checkpoint (SAC) characterized by BUBR1 phosphorylation at Ser670 and Thr680, and cyclin B1 upregulation. Combination treatment enhanced the interaction between mitotic checkpoint complex (MCC) components, including BUBR1, MAD2, BUB3 and CDC20. Further analysis revealed that SZRT components, including senkyunolide-A, trans-neocnidilide, 3-butylidenephthalide, betulinic acid and linoleic acid, were responsible for B7E2 activities. Three B7E2 batches showed a good chemical similarity and similar activities between batches. The data suggest that B7E2 is a potential chemosensitizer in potentiating vinorelbine-induced anti-NSCLC activity through amplification and prolongation of SAC activation.

Polydopamine-induced biomimetic mineralization strategy to generate hydroxyapatite for the preparation of carbon fiber composites with excellent mechanical properties

Living organisms have developed a miraculous biomineralization strategy to form multistage organic-inorganic composites through the orderly assembly of hard/soft substances, achieving mechanical enhancement of materials from the nanoscale to the macroscale. Inspired by biominerals, this study used polydopamine (PDA) coating as a template to induce the growth of hydroxyapatite (HAP) on the surface of carbon fibers (CFs) for enhancing the interfacial properties of the CF/epoxy resin composites. This polydopamine-assisted hydroxyapatite formation (pHAF) biomimetic mineralization strategy constructs soft/hard ordered structure on the CF surface, which not only improves the chemical reaction activity of the CFs but also increases the fiber surface roughness. This, in turn, enhances the interaction and loading delivery among the fibers and the matrix. Compared to the untreated carbon fiber/epoxy resin (CF/EP) composites, the prepared composites showed a substantial enhancement in interlaminar shear strength (ILSS), flexural strength, and interfacial shear strength (IFSS), with improvements of 45.2 %, 46.9 %, and 60.5 %, respectively. This can be attributed to the HAP nanolayers increasing the adhesion and mechanical interlocking with the CFs to the matrix. This study provides an interface modification method of biomimetic mineralization for the preparation of high strength CF composites.

Comparative study of hybrid, tri-hybrid and tetra-hybrid nanoparticles in MHD unsteady flow with chemical reaction, activation energy, Soret-Dufour effect and sensitivity analysis over Non-Darcy porous stretching cylinder

Present study investigates influence of Soret-Dufour effects on MHD unsteady flow of a tetra-hybrid nanofluid (Al2O3, Cu, SiO2 and TiO2 with base fluid water) within non-Darcy porous stretching cylinder. Additionally, chemical reaction, activation energy, and heat generation are considered. This research contributes to the understanding of how these nanofluids can optimize heat and mass transfer process in applications such as advanced cooling systems, solar collectors, biomedical devices, and chemical reactors. Tetra-hybrid nanofluids are selected as per novel aspects for their exceptional ability to adapt their properties for diverse applications, including advanced thermal management systems and scenarios requiring high thermal and electrical conductivity. The comparison between hybrid, tri-hybrid, and tetra-hybrid nanofluids serves to evaluate how increasing complexity and diversity in nanoparticle combinations impact thermal and flow characteristics. The prevailing PDE's undergo transformation into nonlinear ODE's through the utilization of similarity variables and numerically solved using fifth order Runge-Kutta Fehlberg method with shooting method. It is established that rising unsteady parameter values result in increasing velocity profile and rising shape factor parameter result in higher heat transfer. Specifically, the Nusselt number increases by 24 % in the tri-hybrid and 11 % in the tetra-hybrid with a higher Soret number, whereas the Sherwood number decreases by 38 % in the tri-hybrid and 26 % in the tetra-hybrid nanofluid. Employing sensitivity analysis, this study also aims to investigate impact of output responses such as local Nusselt number and local Sherwood number on input parameter Dufour number, Soret number and chemical reaction parameter for tri-hybrid and tetra-hybrid nanofluid. It is found out that Dufour number in tetra-hybrid nanofluid has the more significant impact on the Nusselt number, whereas the Soret number predominantly affects the Nusselt number in tri-hybrid nanofluid. These findings underscore the potential of tetra-hybrid nanofluid in enhancing the performance of various industrial and environmental processes.

Controlled growth of redox-active polymer nanorods on MOF-derived activated nanoporous Carbons: 3D reconstruction study and High-Performance supercapacitor

Supercapacitors, which a energy storage systems, have been continuously studied because of their high power density and rapid charging-discharging capacity. Supercapacitors can be classified into pseudocapacitors and electric double-layer capacitors (EDLCs). The effective utilization of these two supercapacitor mechanisms is important for achieving high performance. In this study, highly nanoporous metal–organic framework (MOF)-derived carbon underwent chemical activation with potassium hydroxide to produce a high surface area. Subsequently, activated carbon was combined with a polyaniline (PANI) nanoarchitecture to introduce redox-active sites. Activated MOF-derived carbon provides a high specific surface area for EDLCs, and well-controlled PANI nanorods support large amounts of redox-active sites to achieve high capacitance. The aniline (ANI) concentration, growth time, acid, temperature, and ammonium persulfate (APS):ANI molar ratio were controlled to grow PANI nanorods without aggregation. At a scan rate of 5 mV/s, the capacitance of the PANI-ZIF-8-derived carbon composite reached 635.3F/g), which was superior than that of ZIF-8-derived carbon (143.4F/g). It also exhibited excellent durability during cycling, demonstrating that it can serve as a high-performance hybrid electrode material composed of carbon and polymer for supercapacitors.

Eco-friendly Activation of Cotton Textiles with LiNbO3 Nanoparticles for Enhanced Self-Cleaning and Antibacterial Performance

Cotton textiles play a universal role in everyday life, but they are prone to stain and serve as a primary channel for transmitting viruses and bacteria. The photocatalytic/antibacterial coatings are highly effective in addressing bacterial contamination on fabrics, although their efficacy diminishes with continuous use and washing. Here, insights are provided into the attachment of LiNbO3 on cotton surfaces using eco-friendly chemical activators to promote resistance to washing cycles, self-cleaning, and bactericide textiles. LiNbO3 nanoparticles were synthesized by low-temperature hydrothermal synthesis and directly applied to cotton fabric using immersion. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) N2 adsorption, diffuse reflectance for band gap determination, and Raman spectroscopy. A simple and effective impregnation method was used, promoting an ester-bond attachment between the cotton surface and the activators. Microscopy analysis (SEM) confirmed the successful deposition of the nanoparticles on cotton fabric. The LiNbO3 coating consisted of transparent layers and did not change the properties of cotton. Methylene blue stains are generally eliminated under UV light after 2 h using nanoparticles and activators. Antibacterial properties were evaluated under visible light through direct contact with bacterial suspensions and culturing. The coated cotton fabric that was activated with oxalic acid exhibited significant photocatalytic antibacterial activity against both Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) bacteria, with bacterial reduction rate above 97 %, even after 10 washing cycles. This performance can be attributed to the effective coupling of LiNbO3 with oxalic acid in the cotton’s surface and its resistance to washing out. This study's novel synthesis and coating method offers an environmentally friendly, cost-effective, and straightforward approach for producing LiNbO3 self-cleaning and antibacterial surface-activated cotton.

Removal of ammoniacal nitrogen from Malaysian palm oil mill effluent (POME) using optimized operating parameters of peat soil as natural adsorbent

Nowadays, the use of natural absorbents to remove pollutants from POME has gained remarkable attention. The main objective of this study is to investigate the suitability and performance of modified peat soil as an adsorbent for the removal of NH3-N from POME. The chemical activation method was performed using readily available NaOH for the first time to improve the adsorption performance of naturally available low-cost peat soil. The physical properties of raw and modified peat soil were determined using water-holding capacity, moisture content, bulk density, porosity, and BET surface area. The adsorbents were also characterized by SEM and FTIR to investigate surface morphology and chemical composition. To optimize the experimental parameters namely adsorbent dosage, agitation rate, and contact time for removal of NH3-N from POME, response surface methodology (RSM) was employed in this study with two different activation ratios. Substantial improvement of physical properties was attained after the modification of raw peat soil. The SEM images of modified peat soil showed a more porous space structure with larger voids while the FT-IR demonstrated the distinctive functional groups in the raw and modified peat soil. At optimized conditions of 5.71 g/L adsorbent dosage, 50 rpm agitation rate, and 38.96 min contact time predicted removal efficiency of NH3-N has been revealed 64.06 and 58.74 % at 1:20 and 1:30 activation ratios, respectively. The experimental investigation using optimized parameters showed 69.12 ± 2.5 and 61.57 ± 4.3 % removal of NH3-N. The experimental and predicted results showed good agreement. The rapid removal of NH3-N (69.1 % within 39 min) was achieved by chemically modified peat soil in this study compared to previously reported studies. Nevertheless, the raw and modified peat soil showed good stability up to three cycles of reusability.

Investigation of a Novel Defatted Spent Coffee Ground (DSCG)-supported Ni catalyst for Fuel Cell and Supercapacitor Applications

With the increase in energy demand, a material that can be used in fuel cell applications has been developed for both energy storage and the use of alternative energy sources to fossil fuels. In this study, a new defatted spent coffee ground (DSCG)-based electrode material was synthesized for two different application areas. A new electrocatalyst synthesis was carried out by subjecting DSCG to chemical activation and carbonization processes. The glycerol electrooxidation performances of the catalysts synthesized at 10-50% Ni loading rates were investigated by CV measurements. 30% Ni-DSCG catalyst exhibited the highest catalytic activity with 3.290mA/cm2.As a result of the electrochemical measurements, 30% Ni-DSCG catalyst with the best catalytic performance was used as the supercapacitor electrode material. The electrochemical performances of the produced supercapacitor electrodes were tested at room temperature using galvanostatic charge-discharge (GCD), Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques, and the capacity and stability of the electrodes were calculated as a result of the findings. In the calculations, the energy and power density of the 30% Ni-DSCG supercapacitor electrode were calculated as 22.897Whkg-1, 841.114Wkg-1, respectively. The supercapacitor electrode capacitance was found to be 50.48F/g.Its cyclic capacity was found to be 90%. It showed that the DSCG-based synthesized electrocatalyst could be a good option for energy storage technology as EDLC electrode material and fuel cell applications as anode catalyst due to its good conductivity, superior cyclic stability, environmental friendliness and low cost.

Air-microwave simultaneously induced carbon fiber surface oxidation and magnetism adjustment by CoOx nanoparticles rapid assembly for interface enhancement and electromagnetic wave absorption of its composites

It is a significant challenge to develop a fast carbon fiber (CF) surface modification method, especially for the high strength electromagnetic wave (EMW) absorption materials. Herein, magnetic CoOx nanoparticles are successfully synthesized and uniformly assembled on CF surface with high oxygen-containing groups by rapid ambient microwave carbon thermal shock (MCTS). The presence of oxygen defect sites on CF surface promotes CoOx nanoparticles nucleation. The number of oxygen defects and the types of magnetic nanoparticles on the CF surface effectively adjust the surface chemical activity and the electromagnetic properties of CF, which is conducive to improving the EMW absorption performance and interface compatibility of the CoOx nanoparticles modified CF reinforced polyamide 6 (CO@CF/PA6) composites. Compared with CO@CF-0 s/PA6, the tensile strength and modulus of CO@CF-3.5 s/PA6 composite are increased by 18.1 % and 18.6 %, respectively. It also displays a minimum reflection loss value (−59.9 dB) at a thinner thickness of 1.9 mm while the maximum effective absorption bandwidth reaches 5.02 GHz with a thickness of 1.8 mm. Its radar cross-section values exhibit less than −10 dBm2 at all tested detection angles. This rapid MCTS shows great potential for large-scale production of CF modification with low-cost, efficient and environmentally friendly process