AppliedChem

In the search of sustainable energy solutions, proton exchange membrane water electrolyzers (PEMWEs) have emerged as a promising alternative for sustainable clean hydrogen production. This study focuses on synthesis and characterization of Ruthenium (Ru)-modified iridium oxide (IrO₂) catalysts. The anode is the principal reason for the high overpotential of PEMWEs and it also greatly increases the cost of the electrolyzers. IrO₂ is highly stable and corrosion-resistant, particularly in acidic environments, making it a durable catalyst for the oxygen evolution reaction (OER) in PEMWEs, though it suffers from a relatively high overpotential. Ruthenium oxide (RuO₂), on the other hand, is more catalytically active with a lower overpotential, but is less stable under the same conditions. In this study, the goal was to improve the catalytic activity and stability of the anode catalyst, IrO₂, through the controlled incorporation of Ru and to reduce overall catalyst cost due to the reduced iridium content. This synergistic combination allows for better performance in terms of conductivity, efficiency, and durability, making Ru-modified IrO₂ an ideal catalyst for OER in PEMWE applications. The Adams fusion method was adapted and used to synthesize the catalysts. The modified catalysts were characterized using analytical instruments. These analyses provided insights into the structural, morphological, and electrochemical properties of the Ru-modified IrO₂ catalysts. Full article

In this paper we provide the reader with a ready to use Group Contribution (GC) method for the heat of formation (gaseous state) of organics in the form of an Excel spreadsheet with all data, enabling further predictions, and an accompanying manual on how to use the GC model for predicting the heat of formation for organics. In addition, in order to widen the applicability of the method whilst retaining chemical accuracy compared to our previous publications on this topic, we include further chemical groups including acetals, benzyl ethers, bicyclic hydrocarbons, alkanediols and glycerol, polycyclic aromatic hydrocarbons, aromatic fluoro compounds, and finally several species which we include to illustrate how the GC model can be successfully applied to species we did not consider during the parameterization of the GC model parameters. Full article

Malaria remains one of the great killers in tropical regions of the world due to the transmission of the Plasmodium parasite by the bites of the female mosquito Anopheles. The resistance of this species to synthetic insecticides contributes to an increase in the incidence of malaria and therefore necessitates the development of new potent and eco-friendly insecticides. In this study, twelve previously reported limonoids from four Entandrophragma species collected in Cameroon have been computationally evaluated for their Anopheles gambiae AChE inhibitory activity. The docking procedure was carried out through Molecular Operating Environment 2019.01 (MOE), while the UCSF Chimera program was used to model the docking results based on interactions between proteins and ligands, and molecular dynamics trajectories were analyzed using the GROMACS 2021.1 tool. Entandrophragmin and encandollens B and C with docking scores ranging from −6.45 to −7.28 kcal/mol were the most promising hits compared to the reference azadirachtin (−6.22 kcal/mol) and were further evaluated for their mechanism of action. Subsequent evaluation classified encandollen C as the best candidate for the development of new potent eco-friendly insecticides based on its lower average RMSD and RMSF and its compactness over a 150 ns duration with acetylcholinesterase. Full article

Recycling olive waste, a major by-product of the olive oil industry, presents significant environmental and economic benefits. This study explores the potential of olive waste (OW) by-products, specifically their individual components such as olive stones (OS), olive oily pomace (OS) and olive oil-free pomace (OF), as sustainable alternatives to wood in eco-friendly composite materials, alongside other residues such as miscanthus, spent mushroom substrate and recycled textile waste. Composite panels were produced with densities ranging from 685 to 907 kg/m³ through thermocompression. The manuscript details the production methodology and assesses the panel’s thermal performance, water absorption, and mechanical strength. The aim is to assess the viability of these alternative materials in producing composites that could serve as environmentally friendly substitutes for traditional wood-based products. Oil-free pomace is a promising and effective alternative to wood, suitable for dry environments. Composite panels composed of miscanthus or spent mushroom substrate and oil-free pomace met the EN 312 standards for general-purpose products in dry conditions, highlighting their potential for use in sustainable applications. Full article

The environmental impacts of the postindustrial era, which rely on fossil fuels, have compelled a reconsideration of the future of energy and chemical industries. Fungi are a valuable resource for improving a circular economy through the enhanced valorization of biomass and plant waste. They harbor a great diversity of oxidative enzymes, especially in their secretome. Enzymatic breakdown of the plant cell wall complex and lignocellulosic biomass yields sugars for fermentation and biofuel production, as well as aromatic compounds from lignin that can serve as raw materials for the chemical industry. To harness the biocatalytic potential, it is essential to identify and explore wild-type fungi and their secretomes. This study successfully combined genome mining and activity screening to uncover the oxidative potential of a collection of underexploited ascomycetes and basidiomycetes. The heme peroxidase and laccase activities of four promising candidates, Bipolaris victoriae, Colletotrichum sublineola, Neofusicoccum parvum and Moesziomyces antarcticus, were investigated to gain a deeper insight into their enzyme secretion. Furthermore, a plant-based medium screening with the phytopathogen C. sublineola revealed that soybean meal is a beneficial component to trigger the production and secretion of enzymes that catalyze H₂O₂-dependent oxidations. These results demonstrate that understanding fungal secretomes and their enzymatic potential opens exciting avenues for sustainable biotechnological applications across various industries. Full article

An Fe-based amorphous coating, with the composition Fe₄₈Cr₁₅Mo₁₄C₁₅B₆Y₂, was synthesized by the high-velocity oxygen fuel spray (HVOF) process on a substrate of AISI 1035. The effect of crystallization on the electrochemical and tribological properties of the HVOF-sprayed Fe-based coating was systematically studied. The XRD results validated the fully amorphous nature of the as-sprayed coating by showing a broad peak at 43.44° and crystallization of this coating after heat-treatment at 700 °C by demonstrating sharp peaks of Fe-, Mo-, and Cr-based carbides. After crystallization, an increase in the corrosion current density from 4.95 μAcm⁻² to 11.57 μAcm⁻² and in the corrosion rate from 4.28 mpy to 9.99 mpy, as well as a decrease in the polarization resistance from 120 Ωcm² to 65.12 Ωcm², were observed, indicating the deterioration of the corrosion resistance of the as-sprayed Fe-based coating. This can be attributed to the formation of porous ferrous oxide, providing an easy channel for charge transfer and promoting pit formation. However, a decrease in the coefficient of friction from 0.1 to 0.05 was observed, highlighting the significant improvement in the wear resistance of the Fe-based coating after crystallization. This can be associated with the precipitation of hard carbides (MxCy) at the boundaries of the crystallized regions. Full article

Carbon dioxide (CO₂) is recognized as the primary cause of global warming due to its greenhouse potential. It plays a significant role in contributing to the emissions arising from a variety of anthropogenic activities, such as energy production, transportation, the construction industry, and other industrial processes. Capturing and utilizing CO₂ to mitigate its impact on the environment is, therefore, of significant importance. To do so, strategies such as net-zero strategies, deploying capture and storage technologies, and converting CO₂ into useful products have been proposed. In this review, we focused our attention on the preparation and performance of polymeric and crystalline materials for efficient CO₂ capture. More precisely, we examined MOFs, petroleum-based polymers (amine-based, polymeric ionic liquid, ionic polymer, conjugated macro/micro-cyclic polymer, and porous organic polymer) as well as bio-based polymers for CO₂ capture. In brief, the present work aims to guide the reader on the available crafted polymeric and crystalline materials offering a promising avenue towards innovative carbon dioxide capture strategy. Full article

The triplet excited state reactivity towards phenolic hydrogen of the α-diketones benzil and 2,2′-furil in the ionic liquid 1-n-butyl-3-methyl imidazolium hexafluorophosphate [bmim.PF₆] was investigated employing the nanosecond laser flash photolysis technique. Irradiation (λ_max = 355 nm) of benzil yields its triplet excited state with λ_max at 480 nm and τ_T = 9.6 μs. Under the same conditions, 2,2′-furil shows a triplet-triplet absorption spectrum with bands at 380, 410, 450, and 650 nm and τ_T = 1.4 μs. Quenching rate constants (k_q) of the reaction between benzil triplet and substituted phenols ranged from 1.4 × 10⁷ L mol⁻¹ s⁻¹ (para-chlorophenol) to 1.8 × 10⁸ L mol⁻¹ s⁻¹ (para-methoxyphenol). A new transient was formed in all cases, assigned to the benzil ketyl. Similar results were obtained for the quenching of 2,2′-furil triplet by phenols, for which k_q ranged from 1.9 × 10⁸ L mol⁻¹ s⁻¹ (para-chlorophenol) to 2.2 × 10⁸ L mol⁻¹ s⁻¹ (para-methoxyphenol). The 2,2′-furil ketyl radical was also observed in all cases (λ_max = 380 nm). The quenching rate constants are almost independent of the substituent and diffusion-controlled (k_q ~ 10⁸ L mol⁻¹ s⁻¹). The proposed mechanism for the phenolic hydrogen abstraction by benzil and 2,2′-furil triplet may involve a proton-coupled electron transfer reaction, ultimately leading to the radical pair ketyl/aryloxyl. Full article

Lemongrass (genus Cymbopogon) is commonly used in foods, beverages, cosmetics, pharmaceuticals, and material science. Cymbopogon ambiguus A. Camus, the Australian Native Lemongrass, is a lesser-known member of the genus Cymbopogon, and research on this plant is scarce. Australian Indigenous people use the stalks and leaves of C. ambiguus as teas. Dried chopped leaves are also used as herbs in cooking. The aim of this study was to determine the proximate composition and bioactive properties of Australian native lemongrass (C. ambiguus). Antimicrobial capacity was carried out using the well diffusion method, antioxidant capacity by the FRAP method, and antidiabetic capacity by using the α-glucosidase inhibitory activity assay. The results obtained in the current study were compared with previously published literature on lemongrass (C. citratus). The results showed that C. ambiguus has lower fat and protein content and lower antioxidant and antimicrobial capacities than C. citratus, but it is very rich in fibre (67.55%) and has strong α-glucosidase inhibitory capacity. The total phenolic and total flavonoid content determined in the aqueous extract of C. ambiguus are also notable. The results of the present study showed that Australian native lemongrass has promising bioactive potential to be used as an alternative native herbal tea. Full article

This article explores the use of olive pit powder (OPP) as a promising resource for enhancing the thermal insulation properties of epoxy mortars. A comprehensive analysis of the chemical and physical characteristics of OPP was conducted, employing analytical techniques including scanning electron microscopy (SEM), thermogravimetric analysis and emitted gas analysis (TG-MS-EGA), and proximal analysis. Experimental samples of epoxy grout were prepared by using different proportions of a conventional inorganic filler, quartz powder, and OPP within an epoxy mortar matrix. As the percentage of OPP in the formulation increased, the microstructure of the samples gradually became more porous and less compact. Consequently, there was a decrease in density with the increase in OPP content. The 28-day compressive strength decreased from 46 MPa to 12.8 MPa, respectively, in the samples containing only quartz (Sample E) and only OPP (Sample A) as a filler. Similarly, flexural strength decreased from 35.2 to 5.3 MPa. The thermal conductivity decreased from 0.3 W/mK in Sample E to 0.11 in Sample A. Therefore, increasing the %wt of OPP improved insulating properties while reducing the mechanical resistance values. This study highlights the potential of OPP as an environmentally friendly and thermally efficient filler for epoxy mortars, thereby promoting sustainable construction practices. Full article

The escalating levels of atmospheric CO₂, primarily attributed to human activities, underscore the urgent need for innovative solutions to mitigate environmental challenges. This study delves into the electrochemical reduction of CO₂ as a promising avenue for sustainable carbon capture and utilization. Focused on the formation of formate (HCOO⁻/HCOOH), a high-value product, the research explores the integration of nonthermal plasma (NTP) with electrochemical processes—an approach rarely studied in existing literature. A comprehensive investigation involves varying parameters such as plasma discharging voltage, carrier gas, discharging mode, electrolysis voltage, polarity, and plasma type. The electrochemical tests employ a 10 wt.% Pd/C catalyst, and formate production is quantitatively analyzed using NMR. Results reveal that NTP significantly enhances CO₂ reduction, with key factors influencing formate yield elucidated. The study reveals the complexity of CO₂ electrochemical reduction, providing novel insights into the synergistic effects of NTP. These findings contribute to advancing sustainable technologies for CO₂ utilization, paving the way for more efficient and environmentally friendly processes in the pursuit of a carbon-neutral future. Full article

Nitrogen (N) is highly reactive and prone to being easily lost into the air and soil water. Biochar–N composites have proven effective in nourishing and improving maize growth. The aim of this study was to synthesize and assess the properties of composites made from biochars (pyrolyzed at 300 °C) derived from chicken manure (N = 3.5%) and leguminous cake (N = 9%) and enriched with ammonium sulfate (AS), urea, and diammonium phosphate (DAP). The biochar pH was adjusted to approximately 6 using sulfuric and phosphoric acids prior to formulating the six tested composites. Maize was cultivated for 50 days under greenhouse conditions, with evaluations of the maize dry matter (DM) and N in the plant shoot. The biochar and composite properties underwent scrutiny for chemical and physicochemical attributes, as well as for soluble N in water and in an HCl solution. Throughout maize cultivation, the release of N as ammonium and nitrate from the composites and pure biochars in the Oxisol solution was successively assessed. Composites formulated with DAP and supplied at a dose of 270 mg kg⁻¹ N yielded the same maize dry matter as composites in which 400 mg kg⁻¹ N was supplied to plants. Regardless of the N source, at the end of maize cultivation, the residual N in the Oxisol was reduced and inadequate for a new cultivation, even in soils treated with urea. Notably, the biochar–N composites, particularly those formulated with DAP, were as effective as urea in nourishing and promoting robust maize growth. In contrast, the maize biomass was lower for plants fertilized with pure biochars, indicating that the N from the carbonized matrices was insufficient for optimal biomass production. Full article

Diabetes mellitus is a chronic metabolic disease that is mainly characterized by hyperglycemia. Chalcones and their derivatives have demonstrated promising pharmacological potential for the treatment of diabetes. The aim of the study was to evaluate antidiabetic activities and analyze 4-methoxychalcone (MPP) using GC-MS. The compound was characterized using mass spectroscopy, nuclear magnetic resonance and headspace with gas chromatography coupled to mass spectrometry (HS-GC-MS). MPP was evaluated via the inhibition of the alpha-glucosidase enzyme, cell viability and antiglycation and hemolytic activities in vitro. The study of the interaction between the bovine serum albumin protein and MPP was investigated via molecular docking. Oral sucrose tolerance and oral glucose tolerance tests were performed in streptozotocin (STZ)-induced diabetic mice. The HS-GC-MS method was able to accurately detect and characterize the compound, and the interaction between MPP and BSA revealed the remarkable affinity for the two main binding sites of BSA. This was confirmed by the in vitro antiglycation test, since MPP showed activity through both oxidative and non-oxidative stress. MPP significantly attenuated the increase in glycemia after glucose loading in STZ-induced diabetic mice. These results confirm that MPP has antihyperglycemic activity and may be an alternative for the treatment of diabetes mellitus. Full article

Wine exerts a fundamental influence on the global market, and its aroma remains a crucial attribute contributing to its commercial value. The market could benefit significantly if a simple and cheap method of analyzing a wine’s aromatic profile were developed. The purpose of this study is to develop such a method. A multi-analytical method for quantifying 39 volatile compounds of wine aroma was developed and validated using liquid–liquid extraction and gas chromatography/mass spectrometry/mass spectrometry (GC-MS/MS). The method was validated for its linearity, reproducibility, recovery, limit of detection, and limit of quantification and showed excellent results for almost all compounds. The method was applied to 25 commercial Protected Designation of Origin “Nemea” wines, and the results were compared and correlated with the sensory analysis results by a trained panel. The correlations among the parameters indicated that the newly developed GC-MS/MS method produces similar results to human responses. Full article

Since the initial 2018 recall of angiotensin receptor blockers due to unacceptable levels of mutagenic N-nitrosodimethylamine (NDMA) impurity, numerous drug products delivering diverse active pharmaceutical ingredients (APIs) have been recalled. Regulators and the industry are working together to understand and address this widescale problem. Conventional analysis of NDMA utilizes liquid or gas chromatography-based procedures that can involve complicated sample preparation and slow sample analysis. Selected ion flow tube mass spectrometry (SIFT-MS) analyses NDMA directly in the gas phase using soft chemical ionization, with an LOQ of 2 ng g⁻¹. Through the novel application of the multiple headspace extraction (MHE) technique, NDMA was quantified directly and rapidly from the drug product without dissolution, at levels well below the regulatory acceptable intake of 96 ng day⁻¹. A comparative analysis of recalled metformin using MHE-SIFT-MS and a conventional liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS) method showed good agreement. Use of the novel MHE-SIFT-MS approach may enable a wider screening of drug products to be conducted, since it provides around a three-fold increase in daily sample throughput. Full article

Nickel nanoparticles have wide-ranging applications in diverse fields, including electronics, catalysis, and biomedicine. The unique properties of these nanoparticles depend on their physical and chemical attributes. Consequently, there is a growing interest in understanding the performance relationships through a nuanced comprehension of their controlled synthesis. This review explores the advancements related to precisely defined nickel nanoparticles, with a specific focus on unraveling the connections between performance and their physical/chemical characteristics. The emphasis is on elucidating how manipulating synthetic parameters, such as precursor concentration, reductant agent properties, temperature, time, and the presence of stabilizing agents, can provide additional avenues for refining the performance in terms of size and morphology. Through the analysis of each variable, we illustrate the methodology for synthesizing well-controlled nickel nanoparticles, showcasing the ability to exert precision over their composition, size, and surface morphology. Full article

The multifaceted health benefits of curcumin (Curcuma longa), attributed to its antioxidant, antitumor, and anti-inflammatory activities, have drawn significant scientific attention. Curcumin shows promise as a potential modulator of macrophage polarization, offering a natural strategy for managing inflammation and promoting tissue repair. However, a limiting factor for this beneficial molecule is its limited bioavailability due to its low solubility in water. This study aimed to quantify the effect of curcumin gold nanoparticle (CurAuNP)-mediated ultrasound irradiation on THP-1-derived macrophages as potential therapeutic targets. The photoreduction method was applied to synthesize the gold nanoparticles with curcumin as a ligand (CurAu). The effect of adding polyethylene glycol in the synthesis process was studied (CurAuPEG). CurAuNP characterization included UV/Vis, Zeta potential, transmission electron microscopy, and FTIR. The amount of singlet oxygen released by curcumin and CurAuNPs was quantified by observing 1.3-diphenylisobenzofuran quenching upon ultrasound irradiation (1 MHz and 1 W/cm²). The results indicated that ultrasound therapy for 4 min with CurAuNPs significantly enhanced singlet oxygen generation and reduced macrophage viability compared to curcumin alone. The increased sonoluminescence and curcumin delivery facilitated by CurAuNPs led to greater curcumin activation. Consequently, CurAuNPs could offer promising therapeutic options for modulating macrophage polarization in pro-inflammatory and anti-inflammatory stages. Full article

This work evaluated the green extraction of oleoresin from pink pepper fruits (OR_PPF) using ultrasound-assisted extraction (UAE) and ethanol as a solvent. The effects of temperature, ultrasound power intensity, sample to solvent ratio and time on the global extraction yield (Y_GE) and phenolic compounds yield (Y_PC) were evaluated. The oleoresin samples were characterized and its antimicrobial activity determined, and the obtained results were compared to conventional extraction in Soxhlet. From the results it was found that the application of the highest levels of the independent variables favored the extraction process. The maximum values of Y_GE and Y_PC were 28.60 wt% and 6.37 mg GAE per g fruit, respectively, obtained at 60 °C, 100% of ultrasound power (165 W), 1:20 g mL⁻¹ (sample:solvent) and 45 min. Under maximized conditions, the OR_PPF obtained by UAE showed a content of phenolic compounds and antioxidant activity inferior to soxhlet–ethanol extraction. However, the time and solvent consumption were reduced. Oleic and linoleic acids predominated in the fatty acid composition of OR_PPF, in addition to sesquiterpenes and gallic and syringic acids. The OR_PPF presented weak antibacterial activity, with minimum inhibitory concentration ranging from 31.25 to 125 mg mL⁻¹. Full article

The hydroxyalkyl amination of agarose gels was studied as an approach to improve adsorption of polyphenols and pharmaceuticals from water. Three commercially available agarose gels, Zetarose FlashFlow4, ZetaCell-CL6B and Sepharose 4B were chemically modified using tris-(hydroxymethyl)aminomethane, TRIS, and ethanolamine, EA. The adsorbed amounts of bisphenol A and diclofenac were significantly higher on TRIS- and EA-derivatives compared with the parent gels. Regarding bisphenol A adsorption on TRIS-ZetaCell-CL6B, a maximal adsorption capacity, Q max of 16 μmol/mL gel and an equilibrium dissociation constant K_L of 2.7 × 10⁻⁴ mol/L were observed. Filtration of diclofenac-contaminated water through TRIS-Zetarose FlashFlow 4 resulted in a 10-fold reduction of the pollutant concentration within 64 column volumes of the effluent. The moderate binding affinity of polyphenols to TRIS- and EA-adsorbents facilitates efficient polyphenol desorption and column regeneration. The effects of TRIS- and EA-substituents in agarose gels, can be harnessed for the development of environmental adsorbents, as well as for the preparative separation of polyphenols and pharmaceuticals. We consider the physical shapes and textures of the prospective adsorbents with a particular focus on spongy macroporous cryogels. These innovative materials hold promise for future applications in liquid and air filtration. Full article