Abstract MXenes, a family of two-dimensional carbides and nitrides based on transition metals derived from MAX phases, have emerged as promising materials for solar energy conversion due to their high metallic conductivity and tunable surface terminations. A sustainable route for synthesizing vanadium-based Bio-MXene (Va 2 CT x ) is developed here using lignocellulosic biomass-derived biochar as a renewable carbon precursor for MAX-phase formation, this is followed by controlled chemical exfoliation. The approach reduces reliance on fossil-derived carbon while enhancing surface functionality and phase purity. Structural and spectroscopic analyses (XRD, SEM–EDX, FTIR, PL, and UV–Vis) confirm effective removal of the Al layer, expansion of the interlayer spacing, the formation of oxygen-rich surface terminations, enhanced visible-light absorption, and bandgap narrowing. Integration with Ta 2 O 5 results in a Ta 2 O 5 /Bio-MXene (Va) composite that achieves a hydrogen evolution rate of 170 μmol g −1 h −1 under natural sunlight, corresponding to a cumulative yield of approximately 1020 μmol g −1 over 6 h, with about 93 % activity retained after 5 cycles. This improvement in performance is mainly attributed to better interfacial charge transfer and suppressed electron–hole recombination facilitated by the Bio-MXene framework, which provides additional electron-transport pathways and active sites. Taken together, these results suggest that biomass-derived MXene heterostructures are a promising and sustainable 2D platform for solar hydrogen generation.
Abstract Rockmelon ( Cucumis melo L.) peels, rich in bioactive compounds, can be upcycled via ecoenzyme technology for cosmeceutical use. This study investigated the chemical profile and bioactivity of ecoenzyme derived antibacterial soap formulated from C . melo L. peels waste with and without whey. The formulations were evaluated for physicochemical stability, enzymatic activity, antioxidant capacity, antibacterial activity, and volatile metabolite composition using GC-MS SPME analysis. The GC-MS profile revealed diverse volatile compounds including phenolic derivatives, aromatic alcohols, and terpenoid compounds associated with antimicrobial and antioxidant functions. All formulations exhibited mildly acidic pH values (5.24–5.75) and high foam stability (82.9–95.1 %). Enzymatic assays confirmed the presence of amylase and lipase activities in ecoenzyme based soaps, indicating retained catalytic functionality after formulation. Fermented samples demonstrated enhanced antioxidant activity, with the whey enriched ecoenzyme exhibiting the strongest radical scavenging activity (IC 50 58.97 ppm). Antibacterial evaluation showed inhibitory activity against Staphylococcus aureus , methicillin-resistant S. aureus, Bacillus cereus, Bacillus subtilis , and Burkholderia glumae . The whey supplemented ecoenzyme also contain the highest phenolic (720.3 mg GAE g −1 ) and flavonoid (552.9 mg QE g −1 ) contents. These findings highlight the potential of fermented C. melo peels ecoenzyme as a sustainable bioactive ingredient for antimicrobial soap formulations and fruit waste valorisation.
Abstract This study examines the potential of pyrolysis as a method of converting plastic waste into fuel in Kinshasa, in the Democratic Republic of Congo (DR Congo), a city facing major environmental challenges due to plastic pollution and energy shortages. The research focuses on the pyrolysis of polyethylene terephthalate (PET), high-density polyethylene (HDPE) and polypropylene (PP) plastics, with the aim of producing clean, affordable energy while tackling the growing problem of plastic waste. The methodology involved collecting plastic waste from local rivers, followed by a slow pyrolysis process that yielded liquid products exhibiting physicochemical properties comparable to those of gasoline and diesel according to selected ASTM quality parameters. The results show that PP gives the highest oil yield, while mixed plastics show variable results depending on their composition. The physicochemical properties of the oils obtained were analysed, demonstrating their potential as alternative fuels. Engine performance evaluations of gasoline–pyrolysis oil blends demonstrated that partial gasoline substitution with crude pyrolysis oil increased brake torque while simultaneously reducing brake specific fuel consumption under the evaluated operating conditions. This study highlights the feasibility of using waste plastics through pyrolysis to contribute to a circular economy, reduce environmental pollution and provide sustainable energy solutions in Kinshasa. Further research is recommended to optimize the pyrolysis process and explore large-scale implementation. Theoretical calculations using quantum chemistry methods at the G4 and M06-2X levels showed that the pyrolysis of polyethylene and polypropylene is initiated by C–C bond scission, with associated energies ranging from 80 to 95 kcal/mol.
Abstract The ongoing prevalence of SARS-CoV-2 variations highlights the urgent need for novel antiviral agents targeting key viral proteins. The papain-like protease (PLpro) is pivotal in viral replication and immune evasion, rendering it a compelling therapeutic target. In the present study, a series of novel thiadiazole- and oxadiazole-based derivatives (12-g & 13a-g) were rationally designed based on the structural features of the known PLpro inhibitor GRL0617. Convergent synthetic strategy was employed to synthesize the target compounds involving the construction of 1,3,4-thiadiazole/oxadiazole intermediates followed by amide coupling with a naphthyl-containing scaffold. All compounds were characterized by 1 H NHMR, 13 C NMR and mass spectrometry and evaluated for their in vitro SARS-CoV-2 PLpro inhibitory activity. Several compounds exhibited potent inhibition, surpassing the reference inhibitor GRL0617 (IC 50 = 2.4 ± 1.1 µM). Among them, oxadiazole derivative (13c) featuring 3-cyanophenyl substitution emerged as the most potent inhibitor with IC 50 value of 0.06 ± 0.8 µM, followed by compounds (12b, IC 50 = 0.3 ± 0.3 µM), (12e, IC 50 = 0.4 ± 1.6 µM) and (13e, IC 50 = 0.6 ± 0.8 µM) respectively. Structure activity relationship (SAR) analysis revealed that electron-withdrawing substituents, particularly cyano group at meta position, significantly enhanced PLpro inhibition whereas methoxy/methyl groups resulted in reduced inhibition. Furthermore, molecular docking studies demonstrated favorable binding interactions of the compounds within the PLpro catalytic pocket through H-bonding, hydrophobic and π–π interactions. Moreover, molecular dynamic simulations confirmed the stability of the ligand-protein complexes throughout the simulation period supporting the experimental findings. The integrated rational design-based synthesis, biological evaluation, and computational investigations collectively identified thiadiazole/oxadiazole scaffolds as promising candidates for the development of SARS-CoV-2 inhibitors, offering valuable insights for next-generation antiviral agents targeting coronavirus proteases.
Abstract The study completed the quantification of 110 compounds from Lianhua Qingwen ( LHQW ) capsule using library-aided ultra-high-performance liquid chromatography-quadrupole-orbitrap-tandem mass spectrometry under three adducting models ([M − H] - , [M + HCOO] - , and [M + H] + ). Especially, 22 groups of isomers (e.g., forsythoside I vs. acteoside vs. forsythoside A) were clearly recognized and 24 “unexpected” compounds were found out for the first time in the capsule. Thereafter, 11 compounds were recommended to construct a new one-for-one anti- counterfeiting quality markers system. Further validated experiment using lower version LC-MS analysis suggested that this system could successfully recognize 11 counterfeiting LHQW capsules.
This study presents a comprehensive characterization of hydrocolloid extracted from mozote (Triumfetta semitriloba) mucilage, evaluating its chemical composition, rheological behavior, and functional properties for food applications. Chemical analysis revealed a high content of uronic acids, hydroxyl and carboxyl groups. Rheological tests showed shear-thinning behavior and Arrhenius-type temperature dependence, with decreasing activation energy at higher concentrations. Time-dependent tests revealed a narrow hysteresis loop and rapid structural recovery, suggesting minimal thixotropy and stable performance under shear. Viscoelastic profiling confirmed weak gel behavior, with G ' exceeding G '' across the linear viscoelastic region and frequency sweep, reflecting a flexible yet stable network supported by reversible interactions. Functional characterization showed a light brown coloration linked to tannins and pigment degradation, with lower luminosity than commercial gums. Exceptional hydration affinity was observed, with no phase separation under centrifugation. Fat adsorption capacity reached 3.71 +/- 0.14 g/g, surpassing values for certain commercial gums. Emulsifying capacity and stability were moderate, with an emulsifying capacity of 9 mL/100 mL and a final emulsion stability of 0.25 mL/mL after heating. These properties suggest that mozote mucilage could offer functionality for texture development, as well as water and fat retention in food systems.
The photocatalytic mineralization of 2-chlorophenol (2-CP) in aqueous media was investigated using pure Zinc oxide (ZnO) and CoO-modified ZnO photocatalysts (CoO/ZnO). ZnO and CoO/ZnO composites were synthesized via two different routes: the sol-gel method and microwave irradiation, followed by calcination at 500 degrees C for 3 h in a muffle furnace. The synthesized materials were characterized by UV-vis diffuse reflectance spectroscopy, Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and scanning electron microscopy (SEM). Incorporation of cobalt oxide into the ZnO lattice reduced the band gap from 3.02 eV to 2.3 eV, significantly enhancing visible-light absorption. Under visible-light irradiation in the presence of 0.01 % H2O2, the CoO/ZnO photocatalyst achieved nearly complete degradation of 40 mg L-1 2-CP within 120 min. At pH 4.0, degradation efficiencies for 40 mg L-1 2-CP were 33.6 % for sol-gel-derived ZnO and 85.3 % for microwave-assisted CoO/ZnO. Furthermore, the CoO/ZnO photocatalyst exhibited excellent stability, retaining high photocatalytic activity over five consecutive reuse cycles. Kinetic analysis revealed a rate constant of 5.7 & times; 10-3 min-1 for CoO/ZnO, which is approximately two times higher than that of pure ZnO, indicating enhanced charge separation and improved generation of reactive oxygen species. These results demonstrate that microwave-synthesized CoO/ZnO nanocomposites are highly efficient and stable visible-light photocatalysts for the degradation of chlorinated phenolic pollutants in water.
This research focuses on the synthesis and application of the organic Schiff base ligand N,N '-bis(salicylidene)ethylenediamine (salen), synthesized from salicylaldehyde and ethylenediamine, as a key molecular recognition element. The salen structure, featuring characteristic imine (-C=N-) and phenolic hydroxyl (-OH) functionalities as tetradentate N2O2 donor sites, was confirmed using Fourier transform-infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy, establishing its structural integrity for Ni(II) chelation. The synthesized salen was subsequently used to modify a screen-printed carbon electrode (SPCE). Electrochemical impedance spectroscopy (EIS) results revealed that salen modification significantly reduced the charge transfer resistance (R ct) from 1231.6 Omega to 296.3 Omega, thereby enhancing electron transfer kinetics. Salen-modified SPCE demonstrated excellent analytical performance for Ni(II) detection using differential pulse anodic stripping voltammetry (DPASV), with limit of detection (LoD) was 4.86 mM, linear range of 10-100 mM (R 2 = 0.9981), sensitivity of 18.13 mu A/mM cm2, and good selectivity against Fe(II) interfering ions. This study highlights the pivotal role of the salen framework in developing cost-effective and efficient electrochemical sensors for environmental nickel monitoring.
Abstract Catalytic ozonation using metal oxides is a promising method for the degradation of persistent organic pollutants like m -cresol. In this study, we explored Mn-supported γ-Al 2 O 3 and SiO 2 for the ozonation of m -cresol (as a model phenolic contaminant) under ambient conditions. The structural and chemical properties of catalysts (2.5 wt% Mn) were determined using TEM, SEM, XRD, FT-IR, and EDX technique. Mn catalysed and uncatalysed ozonation were performed under controlled conditions using activated charcoal (as reference standard) for 24 h by sampling at regular intervals. Kinetic analysis demonstrated a similar trend in activity: 2.5 % Mn/SiO 2 > 2.5 % Mn/γ-Al 2 O 3 > activated charcoal, showing enhanced catalytic character for SiO 2 . Post-reaction studies of degradation intermediates were performed using GC-MS analysis to establish the direction of the reactions. The findings highlight the significant role of support material selection (e.g., high surface area of SiO 2 vs. acidic sites on γ-Al 2 O 3 ) in achieving maximum ozone activation and pollutant mineralization.
This Report is the first of five proposed parts that will in total collect and evaluate the experimental equilibrium constants (and related thermodynamic parameters) for the association of cations with the sulfate ion in aqueous solution. In this Report, quantitative data for the equilibrium: SO4 2-(aq) + H+(aq) -><- $ ightleftharpoons $ HSO4 -(aq) were abstracted by a comprehensive review of the scientific and technological literature, including accessible databases. The equilibrium constants so obtained were accepted or rejected using an explicit set of criteria. The accepted results were then evaluated in closer detail, including comparison with related data. Where possible 'best estimates' under a given set of conditions were calculated as unweighted averages (means) and classified as Reliable, Provisional, or Indicative, depending on the level of agreement among independent measurements. Reliable values of the equilibrium constant and the accompanying enthalpy and entropy changes could be established over wide ranges of temperature, pressure, ionic strength, and electrolyte medium. Nevertheless, gaps in the database remain: in particular, few values for the isobaric heat capacity change are available under any conditions.
Burkholderia oklahomensis LMG 23618 T is a B. pseudomallei -like bacterium originally isolated in 1973 from a wound infection caused by a farming accident in Oklahoma. Metabolic profiling of an organic extract from cultures of B . oklahomensis LMG 23618 T using UHPLC-ESI-Q-ToF-MS led to identification of three known metabolites, betulinan A, yersiniabactin and ulbactin B, in addition to a novel polychlorinated compound. Mass-directed purification enabled isolation of the novel specialized metabolite, which was shown by X-ray crystallography and NMR spectroscopic analysis to be 4,4ʹ-dihydroxy-3,3ʹ,5,5ʹ-tetrachlorobenzophenone. Feeding experiments with stable isotope-labelled precursors established that the carbon skeleton of this unusual metabolite derives from two molecules of tyrosine. This led us to propose a plausible biosynthetic pathway via decarboxylative condensation of 3, 5-dichloro-4-hydroxybenzoic acid with its coenzyme A thioester derivative. The absolute configuration of ulbactin B was also established as 4ʹR, 3ʺS, 7ʺS, 8ʺR using X-ray crystallography and NMR spectroscopy.
Mosquito-borne diseases remain global health threats by documenting 14 million cases and over 1 million deaths yearly. Mosquito-repellent textiles serve as a critical barrier against mosquito-borne disease proliferation, offering a safer alternative to topical applications by minimising transdermal migration. The efficacy of treated fabrics is primarily governed by the interplay between the vapour pressure of the active agents and the fibre-matrix bonding strength. This review provides a comprehensive analysis of the integration of mosquito-repellent agents into textile systems, aligning with the WHO Global Vector Control Response 2017–2030. A key finding of this study is that the pad-dry-cure method significantly outperforms traditional exhaustion methods regarding laundering durability and controlled release kinetics. This review emphasises information on choosing textile materials, methods for applying the repellent to the fabrics, different kinds of active ingredients, and the standardised practices for repellency. Furthermore, the trade-offs between chemical durability and the inherent mechanical properties of the fabric have been addressed. These results offer a technical roadmap for developing high-performance functional textiles that align with United Nations Sustainable Development Goal 3, transitioning the emphasis from immediate protection to sustainable, long-lasting vector control solutions.
The proficient elimination of heavy metals from contaminated water is a critical environmental challenge due to their toxicity and persistence. Mercury has an adverse impact on the immune system and kidneys and is linked to a number of diseases, such as Alzheimer’s and Parkinson’s. Herein, a composite of polypyrrole (PPy) with cobalt ferrite (CoFe 2 O 4 ) was synthesized and evaluated for its removal capacities towards Hg(II) ions. The composites were prepared via in situ polymerization, yielding material with advanced physicochemical properties. Characterization through XRD, FTIR, and SEM confirmed the successful nanocomposite formation, with a particle diameter of around 50 nm. Batch adsorption experiments demonstrated that PPy@CoFe 2 O 4 exhibits significant removal abilities (609.8 mg g −1 ), with equilibrium time achieved in 90 min. Adsorption equilibrium was perfectly characterized by the Langmuir isotherm model, indicating monolayer adsorption. Kinetic investigations revealed adherence to pseudo-second-order kinetics, suggesting chemisorption as the dominant mechanism, while thermodynamic examinations emphasized the spontaneity and exothermic character of the procedure. The prepared PPy@CoFe 2 O 4 can be utilized effectively up to five instances with negligible degradation in performance. Electrostatic interaction is a primary mechanism influencing Hg(II) adsorption onto the surface of PPy/CoFe 2 O 4 . The study contributes to developing affordable and sustainable hybrid material for water decontamination, addressing crucial environmental concerns.
Tetrazole derivatives serve as fundamental components in the synthesis of biological substances, medicinal agents, and explosive material. Multiple methodologies were utilized to synthesize tetrazole including [3 + 2] cycloaddition, Demko-Sharpless and Ugi-Azide etc. The utilization of catalysts such as magnetic nanoparticles makes the synthesis of tetrazole more efficient, cost-effective and environmentally safe. Magnetic nanoparticles are the green catalyst that are easily separated from the reaction mixture without consuming energy and chemicals. Tetrazole is a core structure of various medicines and other scientific components; therefore, advancement in the synthesis of tetrazole derivatives is always indeed. This study discussed the role of magnetic nanoparticles in the green synthesis of tetrazole and its derivatives. This compilation will surely enhance the development of tetrazole derivatives via green routes for future demand.
While a linear economy can no longer sustain the emerging needs of the growing population, a focus on the circular economy, particularly in utilizing renewable energy, will greatly help in meeting the challenges, such as the energy crisis, environmental pollution, and rapid population growth. Hence, a seaweed refinery, similar to a petroleum refinery, helps sustain the production of various chemicals and fuels from seaweed. Seaweed (macroalgae) is a third-generation biomass used to produce biofuels and other products. It is greatly preferred for biofuel production owing to its high growth rate and yield. The maturation of seaweed biorefining technologies is illustrated by advancements in the production of bioethanol which can be produced at yields of 0.25–0.45 g per gram of sugar, biomethane which can be produced at yields of approximately 408 mL per gram of solid (VS) and biocrude which can be produced at yields from 12 to 30 percent by weight. Also, it is readily available and does not require fertilizers or pesticides for crops; hence, it forms a potential candidate for the production of biogas or biofuel. Besides, it is one of the most researched areas that has gained increased research attention in the last year, as it contributes to the Sustainable Development Goals. Though it is extensively used as a green energy source, there is a pressing need to develop novel technologies and materials to meet future energy needs. This review presents various cultivation techniques of seaweed and biotechnology developments for the better valorisation in biofuel production. Further, the major challenges, bottlenecks, and future opportunities of seaweed biorefineries are also discussed.
In the present study, the interaction between an ethanolic solution of metronidazole (C 6 H 9 N 3 O 3 ), hereafter denoted as MTZ, and aqueous solutions of three transition metal ions Iron(III), Cobalt(II), and Nickel(II) was investigated. This interaction led to the formation of three monomeric complexes, C1, C2, and C3, with the respective molecular formulas [Fe(C 6 H 9 N 3 O 3 ) 2 Cl 3 ·H 2 O]·H 2 O, Co(C 6 H 9 N 3 O 3 ) 4 Cl 2 , and Ni(C 6 H 9 N 3 O 3 ) 3 Cl 2 ·H 2 O. The chemical compositions of these complexes were confirmed by elemental (CHNS and metal) analysis, FTIR, Raman, 1 H NMR, magnetic susceptibility, and electronic absorption spectroscopy. The combined results indicate that all complexes are monomeric and that metronidazole coordinates to the metal center in a monodentate manner through the imidazole nitrogen. Spectroscopic and magnetic data further support an octahedral geometry for the complexes. The biological properties of the synthesized complexes were assessed through in vitro antibacterial and antifungal assays against both aerobic and anaerobic strains. Among the tested compounds, the C2 complex exhibited notable inhibitory activity against Enterococcus faecalis and Staphylococcus aureus . Additionally, in silico molecular docking studies were performed to simulate the interactions between the complexes and selected biological targets. The docking results revealed strong binding affinities toward epidermal growth factor receptor (EGFR), a tyrosine kinase enzyme implicated in several cancer types, and dihydropteroate synthase (DHPS), an essential enzyme in the bacterial folate pathway. These findings highlight the promising antibacterial and anticancer potential of the synthesized complexes. Furthermore, the molecular structures of the complexes were optimized using density functional theory (DFT) calculations to support the experimental observations.
Photocatalysis activated by visible light is a highly promising method for environmental remediation, as it effectively harnesses solar energy. In the realm of photocatalysis, there has been a growing interest in metal-organic frameworks (MOFs) as of late. MOFs provide several benefits over standard metal oxide semiconductors, including a large specific surface area, a diverse topology, and a readily adjustable porous structure. However, this method has several limitations in achieving optimal photocatalytic performance, mostly due to the wide band gap and deficiency of redox activity, weak response to visible light, restraining phocatalysis on surface sites. Photocatalysis in MOFs can be developed by coupling with semiconductors or noble metals to enhance and improve the photocatalytic activity. In this work, we investigated Au-ZnCo 2 O 4 /Ce-MOFs nanocomposites (Au: 2 %, 4 % and 6 %) for the visible light-induced photocatalytic degradation of aqueous organic pollutants such as methyl orange and rhodamine B. The composition, texture, structure, and morphology of the nanocomposites were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), Fourier-transform infrared spectroscopy (FT-IR), and N 2 adsorption-desorption (BET) measurements. It was observed that 6 % Au-ZnCo 2 O 4 /Ce-MOFs nanocomposite demonstrated slightly higher photocatalytic activity for the degradation for methyl orange as compared to rhodamine B.
In this work, the nanocomposites comprising Ag-CeVO 4 /Graphene (Ag: 2 %, 4 % and 8 %) were prepared using the hydrothermal method and applied for the photocatalytic degradation of bisphenol A. The nanocomposites were thoroughly characterized using XRD, TEM, SEM-EDX, XPS, FTIR, BET, and DR-UV-Vis techniques. TEM images indicated the sheet like structure with average diameter of 50–100 nm, no big difference in size and morphology was observed among the different prepared nanocomposites. The band gap values were observed in the range 1.26 eV–1.46 eV. The photocatalytic performance was evaluated, and the degradation mechanism was examined in detail. It was perceived that 8 % Ag-CeVO 4 /Graphene nanocomposite demonstrated high photocatalytic activity as compared to CeVO 4 /Graphene, 2 %, and 4 % Ag-CeVO 4 /Graphene nanocomposites. These findings suggest that the incorporation of silver enhances the photocatalytic properties of CeVO 4 /Graphene nanocomposites. Moreover, to understand the mechanism, scavenger experiments were conducted, using the same experimental conditions. It was observed that photogenerated holes (h + ), and superoxide radicals ( . O 2 − ) are the main contributors to the photocatalytic degradation of Bisphenol A. The superior photocatalytic performance of 8 % Ag-CeVO 4 /Graphene nanocomposite highlights its potential as efficient material for environmental remediation applications.
