Fabrication of Asymmetric Supercapacitors (AC@GQDs//AC) with High Electrochemical Performance Utilizing Activated Carbon and Graphene Quantum Dots.

Sugar cane bagasse stands as a prevalent and abundant form of solid agricultural waste, making it a prime candidate for innovative utilization. Harnessing its potential, we embarked on a groundbreaking endeavor to evaluate the sustainability of a molasses-based hydrothermal process to produce graphene quantum dots (GQDs). This pioneering initiative promises remarkable environmental benefits and holds immense economic potential. Embedding crystalline GQDs in activated carbon (AC) boost electrochemical efficiency by enhancing charge-transfer and ion migration kinetics. Optical, structural, and morphological evaluations were used to confirm the formation of GQDs. Transmission electron microscopy (TEM) investigation showed the size, shape, and fact that GQDs were monodispersed, and X-ray diffraction and Fourier transform infrared determined the structure of GQDs. The electrodes with negative (AC) and positive (AC@GQDs) polarity demonstrate a considerable specific capacitance of 220 and 265 F g-1, respectively, when measured at 0.5 A g-1. Additionally, these electrodes exhibit high-rate capabilities of 165 and 230 F g-1 when measured at 5 A g-1, as determined by galvanostatic charge-discharge techniques. The supercapacitor device comprising asymmetric AC//AC@GQDs exhibits a specific capacitance of 118 F g-1. Furthermore, the asymmetric device exhibits exceptional cycling behavior, with an impressive 92% capacitance retention even after undergoing 10,000 cycles. This remarkable performance underscores the immense potential of both the negative and positive electrodes for real-world supercapacitor applications. Such findings pave the way for promising advancements in the field and offer exciting prospects for practical utilization.

Chiral resolution of (±)-flurbiprofen using molecularly imprinted hydrazidine-modified cellulose microparticles.

Flurbiprofen (FP) is one of the non-steroidal anti-inflammatory drugs (NSAIDs) commonly used to treat arthritic conditions. FP has two enantiomers: S-FP and R-FP. S-FP has potent anti-inflammatory effects, while R-FP has nearly no such effects. Herein, molecularly imprinted microparticles produced from hydrazidine-cellulose (CHD) biopolymer for the preferential uptake of S-FP and chiral resolution of (±)-FP were developed. First, cyanoethylcellulose (CECN) was synthesized, and the -CN units were transformed into hydrazidine groups. The developed CHD was subsequently shaped into microparticles and ionically interacted with the S-FP enantiomer. The particles were then imprinted after being cross-linked with glutaraldehyde, and then the S-FP was removed to provide the S-FP enantio-selective sorbent (S-FPCHD). After characterization, the optimal removal settings for the S- and R-FP enantiomers were determined. The results indicated a capacity of 125 mg/g under the optimum pH range of 5-7. Also, S-FPCHD displayed a noticeable affinity toward S-FP with a 12-fold increase compared to the R-FP enantiomer. The chiral resolution of the (±)-FP was successfully attempted using separation columns, and the outlet sample of the loading solution displayed an enantiomeric excess (ee) of 93 % related to the R-FP, while the eluent solution displayed an ee value of 95 % related to the S-FP.

Enhance the oral insulin delivery route using a modified chitosan-based formulation fabricated by microwave.

Chitosan (Cs) was subjected to ball milling and subsequently functionalized with Dinitro salicylic acid (Cs-DNS) to enhance the efficacy of oral insulin delivery. The hydrodynamic spherical particle sizes exhibited 33.29 ± 5.08 nm for modified Cs-DNS NPs. Irrespective of insulin entrapment, zeta potential measurements revealed positively charged Cs-DNS NPs (+ 35 ± 3.5 mV). The entrapment performance (EP%) was evaluated in vitro, and insulin release patterns at various pH levels. The EP% for Cs-DNS NPs was 99.3 ± 1.6. Cs- DNS NPs retained a considerable amount of insulin (92 %) in an acidic medium, and significant quantities were released at increasing pH values over time. In vivo investigations, the diabetic rats which taken insulin-incorporated NPs had lower serum glucose levels (SGL) after 3 h to (39.4 ± 0.6 %) for Cs- DNS NPs. For insulin-incorporated Cs- DNS NPs, the bioavailability (BA%) and pharmacological availability (PA%) were 17.5 ± 0.31 % and 8.6 ± 0.8 %, respectively. The assertion above highlights the significance and effectiveness of modified chitosan in promoting insulin delivery, decreasing SGL levels, and guaranteeing safety.

Biodegradable wound dressing-based collagen/hyaluronic acid loaded antibacterial agents for wound healing application.

Three biodegradable wound dressing based on binary Collagen (COL), Hyaluronic acid (HA) crosslinked loaded with silver nanoparticles (AgNPs), Gentamicin (GENT) and AgNPs/GENT successfully prepared using freeze drying technique. Chemical evaluations for synthesized membranes were carried out using FTIR- ATR. While physical properties were evaluated through swelling and degradation percent. Antibacterial activity was evaluated against G+, G-, yeast and fungi. Finally, cytotoxicity and wound healing evaluations were carried out against skin fibroblast normal cell line, while anti-inflammatory evaluated using RAW 264.7 macrophage cell line. The three produced membrane showed physically interaction between polymer network and the loaded antibiotic. Swelling properties showed superior results for three membranes. Degradability of prepared sheets was rapidly no more than three days. Toxicity evaluations and anti-inflammatory showed superior results for all examined samples except mixed with AgNPs and Gentamicin (GENT). Antibacterial activity showed resistance to G+, G- and yeast. All prepared sheet showed safe towards cell except COL/HA/AgNPs/GENT. Wound healing studied showed efficient of both COL/HA/AgNPs and COL/HA/GENT compared to blank and mixed membrane COL/HA/AgNPs/GENT. The obtained results recommended COL/HA loaded individually either AgNPs or Gentamicin (GENT) as antibacterial and wound healing sheet rather than mixed prepared membrane.

Decorated Au NPs on lignin coated magnetic nanoparticles: Investigation of its catalytic application in the reduction of aromatic nitro compounds and its performance against human lung cancer.

In the recent years, bio-functionalized noble metal doped advanced magnetics nanocomposite materials has been materialized as potential featured catalysts in diverse applications. In this connection, we report herein a novel biogenic lignin driven Au nanoparticle supported Fe3O4 composite material. The procedure is free from any harsh reducing or stabilizing agent. Morphology and structural features were assessed following different physicochemical methodologies like FT-IR, FE-SEM, TEM, EDS, XRD, VSM and ICP-OES techniques. Thereafter, the [Fe3O4/Lignin/Au] material was successfully employed in the efficient reduction of different nitroarenes in aqueous medium. The process was monitored over UV-Vis spectroscopic study. Excellent yields were achieved with a range of diverse functionalized nitroarenes within 10-45 min of reaction. The nanocatalyst was recycled 10 times without any significant loss of catalytic activity. Distinctiveness of the material's activity was validated by comparing the results in the reduction of 4-nitrophenol. Furthermore, the prepared [Fe3O4/Lignin/Au] nanocomposite system exhibited outstanding antioxidant and anticancer effects against five lung cancer cell lines, such as, BICR 3, BICR 78, CALU 1, ChaGo-K-1, and A549. Cytotoxicity assay was determined in terms of % cell viability following MTT protocol. The corresponding IC50 values were obtained as 47, 31, 19, 25, and 31 µg/mL respectively.

A Study of the Synthesis and Characterization of New Acrylamide Derivatives for Use as Corrosion Inhibitors in Nitric Acid Solutions of Copper.

The objective of this research was to explore the impact of corrosion inhibition of some synthetic acrylamide derivatives 2-cyano-N-(4-hydroxyphenyl)-3-(4-methoxyphenyl)acrylamide (ACR-2) and 2-cyano-N-(4-hydroxyphenyl)-3-phenylacrylamide (ACR-3) on copper in 1.0 M nitric acid solution using chemical and electrochemical methods, including mass loss as a chemical method and electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) as electrochemical methods. By Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1HNMR), and mass spectroscopy (MS) methods, the two compounds were verified and characterized. There is evidence that both compounds were effective corrosion inhibitors for copper in 1.0 M nitric acid (HNO3) solutions, as indicated by the PP curves, which show that these compounds may be considered mixed-type inhibitors. With the two compounds added, the value of the double-layer capacitance was reduced. In the case of 20 × 10-5 M, they reached maximum efficiencies of 84.5% and 86.1%, respectively. Having studied its behavior during adsorption on copper, it was concluded that it follows chemical adsorption and Langmuir isotherm. The theoretical computations and the experimental findings were compared using density functional theory (DFT) and Monte Carlo simulations (MC).

Carboxymethyl cellulose mediated growth of V2O5 nanorod by green strategy for energy storage utilization using electrochemical studies.

Vanadium pentoxide has the most exciting oxidation states, but, Vanadium pentoxide (V2O5) has low capacitance due to poor electrical conductivity and ionic diffusivity. So, encapsulating pentoxide in carbonaceous materials or metals, shrinking it to the nanoscale, or changing its morphology can improve capacitance performance. Herein, we describe a green synthesis of V2O5NPs with carboxymethyl cellulose (CMC) that typically acts as a reducing and stabilizing agent using the -COOH and -OH group. The physicochemical characterization of prepared samples reveals the prominent peak in UV-vis spectra at 265 nm confirming the formation of V2O5NPs with particle sizes between 200 and 220 nm. The theoretical surface area for the nanocomposite was 76.5 m2/g. The calcination temperature is essential to determine a material's specific capacitance. Due to decreased oxide agglomeration, the V2O5-green modified electrode exhibits superior electrochemical performance around 223 F g-1 than Ac alone (160 F g-1). The finding demonstrated excellent cyclic stability with reduced fluctuation in capacitance. Because of its exceptional electrochemical performance and simplicity of access, this AC/V2O5 nanocomposite can be helpful as an electrode for energy storage applications.

The Design of Ternary Composite Polyurethane Membranes with an Enhanced Photocatalytic Degradation Potential for the Removal of Anionic Dyes.

Photocatalysis is an efficient and an eco-friendly way to eliminate organic pollutants from wastewater and filtration media. The major dilemma coupled with conventional membrane technology in wastewater remediation is fouling. In this study, the photocatalytic degradation potential of novel thermoplastic polyurethane (TPU) based NiO on aminated graphene oxide (NH2-GO) nanocomposite membranes was explored. The fabrication of TPU-NiO/NH2-GO membranes was achieved by the phase inversion method and analyzed for their performances. The membranes were effectively characterized in terms of surface morphology, functional group, and crystalline phase identification, using scanning electron microscopy, Fourier transformed infrared spectroscopy, and X-ray diffraction analysis, respectively. The prepared materials were investigated in terms of photocatalytic degradation potential against selected pollutants. Approximately 94% dye removal efficiency was observed under optimized conditions (i.e., reaction time = 180 min, pH 3-4, photocatalyst dose = 80 mg/100 mL, and oxidant dose = 10 mM). The optimized membranes possessed effective pure water flux and excellent dye rejection (approximately 94%) under 4 bar pressure. The nickel leaching in the treated wastewater sample was determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). The obtained data was kinetically analyzed using first- and second-order reaction kinetic models. A first-order kinetic study was suited for the present study. Besides, the proposed membranes provided excellent photocatalytic ability up to six reusability cycles. The combination of TPU and NH2-GO provided effective strength to membranes and the immobilization of NiO nanoparticles improved the photocatalytic behavior.

Correction: Imaging the reactivity and width of graphene's boundary region.

Correction for 'Imaging the reactivity and width of graphene's boundary region' by Huda S. AlSalem et al., Chem. Commun., 2020, 56, 9612-9615, DOI: 10.1039/D0CC02675A.

Imaging the reactivity and width of graphene's boundary region.

The reactivity of graphene at its boundary region has been imaged using non-linear spectroscopy to address the controversy whether the terraces of graphene or its edges are more reactive. Graphene was functionalised with phenyl groups, and we subsequently scanned our vibrational sum-frequency generation setup from the functionalised graphene terraces across the edges. A greater phenyl signal is clearly observed at the edges, showing evidence of increased reactivity in the boundary region. We estimate an upper limit of 1 mm for the width of the CVD graphene boundary region.

Characterisation, coverage, and orientation of functionalised graphene using sum-frequency generation spectroscopy.

We report the unambiguous detection of phenyl groups covalently attached to functionalised graphene using non-linear spectroscopy. Sum-frequency generation was employed to probe graphene on a gold surface after chemical functionalisation using a benzene diazonium salt. We observe a distinct resonance at 3064 cm-1 which can clearly be assigned to an aromatic C-H stretch by comparison with a self-assembled monolayer on a gold substrate formed from benzenethiol. Not only does sum-frequency generation spectroscopy allow one to characterise functionalised graphene with higher sensitivity and much better specificity than many other spectroscopic techniques, but it also opens up the possibility to assess the coverage of graphene with functional groups, and to determine their orientation relative to the graphene surface.