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AbstractRecently, earth-abundant compounds can be coordinated to the vacant site(s) of lacunary polyoxometalates as water oxidation catalysts (WOCs). Herein, a new catalyst was synthesized based on potassium salt of tri barium-coordinated polyoxometalate (K9[PW9Ba3O34] (denoted as Ba-POM) by reaction of [PW12O40]3- and BaCl2 at pH = 7.5. The prepared PW9Ba3O37 indicated excellent chemical water oxidation activity in the presence of ceric (IV) ammonium nitrate (CAN) as a sacrificial electron acceptor. The synthesized catalyst was characterized by Ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) techniques. In following, the effect of Ba substitution in the structure of POM unit, the role of oxidation activity in water splitting, and also the effect of temperature and acid conditions were discussed. [ABSTRACT FROM AUTHOR]

N4-donor Schiff base copper(II) nanoparticles were easily prepared through surface modification of silica-coated magnetite nanoparticles (Fe3O4@SiO2) with pyrrole 2-carbaldehyde Schiff base and a subsequent reaction with Cu(CH3COO)2.H2O in ethanolic solution. This nanocatalyst was characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and magnetization. Efficient oxidation of alkenes and alcohols was carried out over the Schiff base copper(II) nanoparticles. Catalytic tests showed that the catalyst was particularly effective for the oxidation of α-methyl styrene, norbornene, benzyl alcohol, and benzohydrol. The results showed that acetophenone, 2-norbornanone, benzoic acid, and benzophenone with selectivity values of 88, 100, 100, and 100, respectively, were obtained. The heterogeneous catalyst of N4-donor Schiff base copper(II) offers advantages such as ease of product separation, catalyst recycling, and ease of preparation. Antibacterial tests against two gram-positive and two gram-negative bacterial species found that the bacteria stopped growing in the catalyst medium. HIGHLIGHTS: A novel nanomagnetic heterogeneous catalyst of N4-donor Schiff base copper(II) immobilized on superparamagnetic Fe3O4@SiO2 was Synthesized. Catalyst was characterized by TGA, XRD, FT-IR, TEM, and magnetization. Fe3O4@SiO2@APTMS@PYC@Cu was used as an efficient nanocatalyst for oxidation of alkenes and alcohols. Nano-catalyst antibacterial studies were performed. The catalyst has high catalytic capability, excellent magnetic separately, and reusability. [ABSTRACT FROM AUTHOR]

Hydrogen fuel cells are vital for green energy to replace traditional energy. However, their lifetime is an important factor limiting their development. In this study, commercial materials were used to prepare proton exchange membrane fuel cells (PEMFCs), and pure oxygen was used as the cathode gas to accelerate their lifetime evaluation. The components of the membrane electrode assembly were characterized, and significant thinning was observed in the local proton exchange membrane (PEM). Therefore, the uniformity of the internal conditions of the fuel cell is the key to ensure a long lifetime. The hydrophilicity of the gas diffusion layers increased as the carbon disorder increased via the adsorption of hydrophilic chain segments produced by PEM degradation. The growth of platinum particles in the catalyst layer reduced the electrochemical active area of the catalyst, but the reduction rate slowed and then stabilized. This study of the lifetime of PEMFCs and changing properties of commercial materials clarifies the existing problems of fuel cells and contributes to the development of long-life fuel cells. [ABSTRACT FROM AUTHOR]

In this study, solid acid magnetic nanoparticles Fe3O4@SiO2-S-Bu-SO3H were prepared under appropriate conditions and characterized by various analytical techniques including FT-IR, XRD, FE-SEM, EDX, and VSM. Finally, the catalytic activity of the synthesized Fe3O4@SiO2-S-Bu-SO3H MNPs was investigated for the synthesis of valuable benzothiazole derivatives by the condensation reaction of ortho-aminothiophenol and various aldehydes under ultrasonic conditions. In the presence of the inexpensive, environment-friendly, magnetically recoverable solid acid catalyst, the benzothiazoles were obtained as pure target products in excellent yields (90–98%) and short reaction times (3–11 min). The synthesized Fe3O4@SiO2-S-Bu-SO3H MNPs show great catalytic activity because of the combined effect of Brønsted acidity and high functional group density. This solid acid magnetic nanocatalyst is reusable for several cycles and can be easily segregated from the reaction mixture. In this research, we have successfully developed ultrasonic assisted a green and efficient methodology for the synthesis of the 2-substituted benzothiazole derivatives using MNPs Fe3O4@SiO2-S-Bu-SO3H as a low-cost, environment-friendly, and reusable catalyst with excellent yields and very short reaction times. [ABSTRACT FROM AUTHOR]

The aza-Michael addition reaction of primary and secondary amines to α,β-unsaturated olefins viz; acrylonitrile, phenyl vinyl sulfone and dimethyl maleate has been carried out using 5–10 mol% Co(NO3)2.6H2O as a catalyst in t-BuOMe at 80–100 °C, giving rise to the desired β-aminocarbonyl compounds or sulfones in moderate to good yields. A wide range of aromatic amines, even those bearing electron withdrawing groups could be added to activated olefins via this strategy. Addition of (hetero)aromatic amines were also feasible, while in case of 2-aminopyridine the reaction was found to be effective only when AgOTf was added along with the catalyst. The aliphatic amines; benzylamine, dibenzylamine, di-n-butylamine were also smoothly added to acrylonitrile and phenyl vinyl sulfone. The methodology describes cobalt(II) nitrate as an eco-friendly, cheap and shelf available catalyst suitable for performing the Michael-type hydroamination reactions. [ABSTRACT FROM AUTHOR]

Various advanced sources have been developed to cope with the exponential need for world energies, such as hydrogen production, photovoltaic solar cells, lithium batteries and fuel cells, etc. Among these, fuel cells are better owing to their power production, renewability, and green natural technology. In fuel cells, chemical energy is converted into electrical energy with the help of an electrochemical device, having three major components, i.e. electrodes, electrolytes and catalysts. Bismuth-based materials would be a good choice to develop an efficient fuel cell and can be used as electrodes, electrolytes, and catalysts. Bi2SiO5@NG(NG = nitrogen-doped graphene) is a Bi-based nano-composite used as a cathodic catalyst to enhance the oxygen reduction reaction (ORR). Co−Bi@rGO (rGO = reduced graphene oxide) is used as an anode for an EtOH fuel cell due to its low cost and high efficiency. Bi-based solid oxide electrolytes, e.g. sulfonated poly(ether, ketone) (SPEEK) polymer having 7.5 wt.% of bismuth cobalt zinc oxide (BCZO) with a high-power density of 574 mW cm−2 have been reported in this regard. These factors accentuate the relevance of bismuth-based materials for the production of components for fuel cells that have excellent performance. This review examines the published literature on bismuth-based materials and anticipates the synthesis, and role of material in fuel cells. Finally, current challenges and future perspectives present comprehensive guidelines for future research. [ABSTRACT FROM AUTHOR]

Fuel cells are promising fossil fuel alternatives that are both environmentally friendly and powerful. Direct methanol fuel cells are particularly suitable for lightweight cars and portable electronics. Developing efficient, cost-effective, and eco-friendly catalysts for energy storage and conversion devices is vital for long-term energy security. Numerous studies have explored using metal oxides and modifications to mixed transition metal oxide (MTMO)-based catalysts to enhance the methanol oxidation process. Coupling transition metals (Mn, Co, Ni, Fe, Zn, etc.) in MTMOs improves redox processes and electronic conductivity, advancing electrochemical applications. Among these, nickel cobaltite (NiCo₂O₄) stands out due to its material stability and higher electronic conductivity compared to single-component metal oxides NiO and Co₃O₄. NiCo₂O₄ shows great potential as a composite-based material for fuel cell applications. This paper reviews studies on NiCo₂O₄ as composite-based materials for electrocatalysts, including various methods for synthesizing nanostructures suitable for direct methanol fuel cells. It also highlights the challenges and potential benefits of using NiCo₂O₄ in practical energy storage systems, offering valuable perspectives and insights for early-stage researchers focused on future research and development in composite-based materials for energy applications. [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTY STATEMENTThe synthesis of catalysts has gained specific concern due to their versatile applications in particular azo dye decolorization. In the current work, metallic nanoparticles (copper and silver) were In-situ biosynthesised using Allium sativum and Chondrilla juncea extract. The obtained Allium-copper oxide and Allium-silver oxide materials were analyzed using SEM, TEM, FT-IR, TGA-DTG, SEM, TEM, and XRD techniques. Allium peels had a rough surface, with nanoparticles equally distributed over it. The crystal structure of Allium peels was altered after the addition of CuO and AgO nanoparticles. The highest residual mass values in the prepared materials indicated that the metallic nanoparticles were, in situ, formed. The prepared materials had worse thermal stability than Allium peel powders. The azo dyes, Calmagite and Naphthol Blue Black B were tested in the catalytic power of the resulting materials. The decolorization process was affected by the dye structure, amount of H2O2, dye concentration, time of reaction, and temperature of the bath. The activation energy values for Allium-CuO were 18.44 kJ mol−1 for calmagite, and 23.28 kJ mol−1 for naphthol blue black, respectively. Nevertheless, the energy values for Allium-AgO were 50.01 kJ mol−1 for calmagite and 12.44 kJ mol−1 for Naphthol blue black. The calculated low energy values for the prepared materials suggested the high efficiency of the use of these catalysts in azo dye decolorization under the change of some main experimental conditions.Chondrilla juncea was employed as a biological extract for in-situ reduction of copper and silver ions within Allium sativum peels. The resulting Allium sativum-CuO and Allium sativum -AgO materials were used as efficient catalysts for azo dye decolorization. [ABSTRACT FROM AUTHOR]

In this study, the photocatalytic degradation of an aqueous solution containing a mixture of Direct Black 10 B dye using titanium dioxide (TiO2) as a catalyst was investigated. The degradation of Direct Black 10 B dye was studied for several parameters, including the catalyst, dosage, initial concentration of dye, and pH. Variable catalyst quantities (0.25, 0.50, 0.75, 1, and 1.25 g), pH (3, 5, 9, and 11), and beginning dye concentration were used in the studies (62.5, 125, 250 and 500 ppm). 0.75 g/litre of catalyst was found to be the ideal dose. The ideal catalyst concentration was determined to be 0.75 g/litre, and the maximal dye decolourization rate was further studied in a basic media, i.e. at pH 9 Blue turned into grey and finally white in the acidic medium, whereas blue turned into pink and then white in the basic medium. After 3 hours 98% of the colour was completely removed at this optimal point. The Langmuir, Freundlich and Temkin isotherms were examined. The langmuier isothers with regression coefficient 0.99 is best fitted as compared to Freundlich and Temkin isotherms. The findings of the kinetic analysis suggest that the Pseudo Second order with regression coefficient 0.9923 is best suited as compared with the pseudo first order and Intra-particle diffusion model. [ABSTRACT FROM AUTHOR]

A novel electrochemical reactor with a rotating anode attached to its end with four baskets as catalysts holders is proposed for deep desulfurization of diesel fuel. In this reactor two experimentally prepared catalysts of (5% manganese oxide (MnO2)/modified activated carbon (MAC) and 5% iron oxide (Fe2O3)/MAC) were used for an efficient desulfurization process. This design is characterized by conducting two functions at the same time, which are to agitate the reaction mixture and to move the catalyst over all areas of the reaction vessel. Several experiments were conducted at different operating conditions such as voltage, reaction time, and agitating speed. Results showed that the proposed basket reactor is excellent and highly effective in removing dibenzothiophene (DBT) in diesel. The removal efficiency of sulfur compounds is significantly improved by enhancing reaction times, stirring speed, and cell voltage up to 3 volts and drops at higher than 3 volts. At all operating conditions, the 5% Fe2O3/MAC catalyst showed higher performance than the 5% MnO2/MAC catalyst. This result can be attributed to the high reactivity of Fe2O3/MAC toward DBT removal and its magnetic activity which could enhance the oxidation reaction. Under the best operating conditions, the removal efficiencies reached 98.8%, and 93.1% for 5% Fe2O3/MAC and 5% MnO2/MAC, respectively. A model for the proposed reactor was also developed using an artificial neural network (ANN) software. The modeling data displayed an excellent agreement between the experimental and predicted data. This interactive model produced an accurately strong basis for the behavior of the new electrochemical desulfurization (ECDS) process. [ABSTRACT FROM AUTHOR]

Herein, three g-C3N4(MCN/TCN/UCN), obtained by the direct pyrolysis of melamine/urea/thiourea respectively, were introduced as supports to optimize the NH3-SCR activity of Ce-W-Ti catalyst. Compared to CWT-400-Air, CWT@g-C3N4(2)-300-N2 exhibits lower crystalline anatase TiO2 and larger specific surface area, which improves the dispersion of Ce/W/Ti species on catalysts surface. Furthermore, the introduction of g-C3N4 as supports also contributes to doping C/N elements into Ce-W-Ti catalyst and increases the Ce3+/(Ce3++Ce4+) and Oα/(Oα+Oβ) molar ratios on catalyst surface. These all are advantageous to the NH3-SCR activity. However, UCN shows better promotional effect than MCN and TCN. This might be mainly attributed to the loose and porous stacked layered fold structure of UCN, the larger BET surface area, higher dispersion of Ce/W/Ti species and moderate weak/medium-strong acid sites of CWT@UCN(2)-300-N2. At the same time, the influence of carbon nitride amount, calcination atmosphere and calcination temperature on the NH3-SCR activity of CWT@g-C3N4 catalyst were also investigated. [ABSTRACT FROM AUTHOR]

A series of basic functional ionic liquids were prepared from 1, 4-diazabicyclo [2.2.2] octane (DABCO) with various halogenated hydrocarbons, then these functional ionic liquids were used as catalysts for the chemical fixation of CO2 into cyclic carbonates and the influence of the structure of the ionic liquids was investigated. The results showed that the N atom active center, types of anions and hydrogen bond of the catalyst play a key role in the cycloaddition reaction of CO2 with epoxides to cyclic carbonates. Under mild reaction conditions (T = 100 °C, 1 atm CO2), the ionic liquid [DABCO-CH2CH2CH2OH] I showed the best catalytic effect, which has notable advantages such as high catalytic activity, eco-friendly, ease of work-up and convenient reuse. [ABSTRACT FROM AUTHOR]

NiO nanoparticles were synthesized from pine cone extract by green synthesis method, which is a simple, cost-effective, environmentally friendly and sustainable method. The particle size of NiO nanoparticles was determined to be in the range of 10–25 nm by X-diffraction differential and transmission electron microscope analysis, and the bandgap energy of NiO nanoparticles was determined to be 2.66 eV. The catalytic effect of NiO nanoparticles in both microwave-assisted sodium borohydride hydrolysis and photocatalytic reduction of methylene blue was examined and it was determined that they had a high catalytic effect in both applications. It was determined that the hydrogen production rate in sodium borohydride hydrolysis was 1135 mL/g/min. The activation energy of sodium borohydride hydrolysis is 29.69 kJ/mol and 29.59 kJ/mol for the nth-order and Langmuir Hinshelwood kinetic models, respectively. In the photocatalytic reduction of methylene blue with NaBH4, it was determined that the reduction did not occur in the absence of a catalyst, but in the presence of the catalyst, the reduction occurred 98% in 3 min. It was determined that NiO nanoparticles were used five times in the photocatalytic reduction of methylene blue and the reduction efficiency for the fifth time was 93%. It was determined that the photocatalytic reduction of methylene blue was pseudo-first order and the rate constant was 1.63 s−1. It was determined that NiO nanoparticles synthesized by the environmentally friendly green synthesis method can be used as catalysts for two different applications. NiO nanoparticles were synthesized from pinecone extract in a simple, cost-effective, and green method. The synthesized NiO nanoparticles were characterized using various characterization techniques. NiO nanoparticles have high activity both in the photocatalytic reduction of methylene blue and in the hydrolysis of sodium borohydride, and they are catalysts with high activity in two different applications. Photocatalytic reduction of methylene blue with uncatalyzed NaBH4 was not achieved and was completed in 3 min in the presence of NiO nanoparticle catalyst. It was determined that the hydrogen production rate in sodium borohydride hydrolysis was 1135 mL/g/min. NiO nanoparticle catalysts have low activation energy for sodium borohydride hydrolysis. [ABSTRACT FROM AUTHOR]

AbstractMnO and Ba-doped MnO NPs were prepared through the chemical reduction method and these NPs were used for the photodegradation of Methylene blue dye (MB) dye in an aqueous medium. The morphological study shows that the MnO NPs have granular shapes while Ba-doped MnO NPs have irregular spherical shapes. XRD results presented that the diameter of MnO and Ba-doped MnO NPs was 30 and 36 nm, respectively. FTIR spectra show peaks in the range of 750–1385 cm−1, which present the metal oxide NPs. The photocatalytic degradation study demonstrated that the MnO and Ba-doped MnO NPs degraded about 73 and 86% dye within 250 min, respectively. The effect of various parameters like pH, initial dye concentration, and catalyst dosage on the photodegradation of dye was also studied. The recovered MnO and Ba-doped MnO NPs also significantly degraded the Methylene Blue dye in aqueous media. [ABSTRACT FROM AUTHOR]

This study evaluates the reactivity of acidic resins through mathematical modeling. To assess the reactivity of resins, a copolymerization model was used, making it possible to estimate chain sequences distribution along their polymeric matrices. A model for the reaction catalyzed by these resins, whose equations were based on power law and molar balances, was coupled to the copolymerization model to describe the whole process. Resin properties were collected from the literature and compared to data provided by the copolymerization model, resulting in a linear correlation between the weighted average chain densities measured by ISEC and the total concentration of sequences between cross-links (R2 = 0.988). The prediction ability of the developed model was compared to a literature approach, which depends on an experimental characterization of the resins by Inverse Steric Exclusion Chromatography (ISEC). Akaike Information Criterion revealed that the models exhibit comparable predictive capabilities, demonstrating that the developed model is able to simulate reactions catalyzed by gel-type resins without requiring equipment for morphology characterization. [ABSTRACT FROM AUTHOR]

Cellulose filter paper (CFP) was modified with poly(acrylic acid) (PAA) and/or poly(ethylene glycol)methacrylate (PEGMA), followed by Cu immobilization for 4-nitrophenol (4NP) reduction. Among these samples, Cu-immobilized CFP modified with PEGMA polymer (CFP@PEGMA-Cu) exhibited the highest Cu incorporation of 2.21%. Those having the copolymer (CFP@PAA-co-PEGMA-Cu) demonstrated the highest efficiency, completing 4NP reduction in 3 min with an impressive 99.45% conversion, a high-rate constant (k) of 27.5 × 10−3 s−1, and turnover frequency (TOF) of 18.36 h−1. Notably, the catalysts containing PAA maintained good reusability, preserving 97% conversion upon 9 cycles. These results suggest their promising applications in sustainable catalysis, offering the catalytic potential with simple preparation and low cost required. [ABSTRACT FROM AUTHOR]

Multi-tubular reactors allow for highly selective and mostly highly exothermic catalytic or non-catalytic reactions to occur making them essential in various industrial processes. Our Present work was to develop a generalised rigorous costing method applicable to industrially designed multi-tubular reactors. In this report, a Fischer–Tropsch (F-T) industrial multi-tubular reactor was rigorously costed. Capital costs totalled to R,52,491,606 with material costs attributing the highest cost contribution (48%). The operating cost amounted to R,18,258,067 with cleaning and maintenance attributing the highest cost contribution(67%). The reactor purchase price was evaluated to R,36,201,107. This differed by 41.5% from the purchase price found using a shell and tube heat exchanger costing method. The total annual cost (TAC) assuming a 3-year payback was found to be R,35,755,269. [ABSTRACT FROM AUTHOR]

A catalytic oxidation treatment to remove coloration and chemical oxygen demand (COD) in an effluent from a food industry was carried out using oxygen and ozone as oxidizing agents and activated carbon as a catalytic. Different experiments of oxidation were conducted using 25, 50 and 100 mL of activated carbon bed to treat 100 mL of sample and constant flow of oxygen 7.2 g/min and ozone 0.034 mg/min, maintaining initial pH of industrial effluent. Almost a complete coloration removal and COD reduction of the sample was achieved for catalytic processes; however, time of treatment and agent oxidant doses were different in each case. According to volume of activated carbon beds, ozone doses for discoloration and COD removal were 8.5, 2 and 1.7 mg/L, whereas the oxygen doses were 2860, 770 and 500 g/L, respectively. Consequently, to eliminate the color in the industrial effluent, the dose of oxygen was higher than that of ozone. In addition, the oxidation agents promoted the regeneration of activated carbon, showing that its activity is declined after 60 cycles of effluent treatment with ozone, whereas with oxygen treatment, the total depletion was observed in 18 cycles. In turn, single adsorption showed activated carbon depletion in 5 cycles of effluent treatment. [ABSTRACT FROM AUTHOR]

The paper examines the factors for the 'big moment' of the far right, its Big Bang, i.e, when far-right parties transform from marginal 'groupuscules' into considerable political players. It is the moment when political supply and social demand interact, like two elements in a chemical reaction, and are transformed into far-right vote; the far-right redox. What are the conditions and the catalyst that allow the far-right redox to take place? Discussing the importance of the media as a resource for all political actors, and especially the far-right party family and analysing examples from three Balkan countries (Bulgaria, Romania, Serbia), Greece and France, the working hypothesis is that a necessary and sufficient condition is the occurrence of a media-induced event that acts as a catalyst, leading to their rise from the political margins to the political mainstream. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) have emerged as an environmentally friendly alternative to the volatile organic solvents. Though primarily used as solvents, ILs synthesized with specific desired chemical properties have gained significant attention in recent years due to their unique properties and versatile applications in various areas of chemical synthesis and beyond. The present review is aimed at exploring the synthetic methods for chalcogen (S, Se, Te) ionic liquids along with the study of their role as solvent, catalyst, reactant in various chemical reactions like oxidation reactions, hydrothiolation transformations etc., thus showing the contribution of ILs toward the development of sustainable organo-chalcogen chemistry. [ABSTRACT FROM AUTHOR]

As ferric oxide is a well-known catalyst, aluminum can act as a high energy dense material. Ferric oxide/aluminum can experience nanothermite reaction with novel synergistic characteristics. On the other hand, nitrocellulose (NC) is the most energetic polymeric matrix. This study reports on the facile development of thermite-based NC nanocomposite. Ferric oxide nanoparticles (NPs) of 5 nm size and aluminum NPs of 80 nm size were dispersed in acetone. Colloidal ferric oxide/aluminum NPs were integrated into NC matrix via anti-solvent technique. Nanothermite particles offered an increase in NC decomposition enthalpy by 38.59% using differential scanning calorimetry (DSC). The apparent activation energy of NC was reduced by 14% and 14.5%, using Friedman and OZAW models, respectively. Activation energy at different conversion extent was evaluated, and decomposition mechanisms have been suggested to be heterogeneous solid phase reaction. The developed NC nanocomposite is considered bespoke material for first-fire ignition systems; where molten solid particle and high decomposition enthalpy are highly appreciated. [ABSTRACT FROM AUTHOR]

This study focused on the catalytic pyrolysis of Paulownia (P. elongota) wood. The effects of ZSM-5, Na2CO3, sepiolite, and catalyst ratio (10-80% by wood weight) on product yields and bio-oil composition were investigated. In pyrolysis experiments, 500°C pyrolysis temperature, 50°C min-1 heating rate, and 100 mL min-1 N2 flow rate were kept as constant. The catalyst type and catalyst ratio changed the product yields and bio-oil compositions. Pyrolysis conversion was increased for all catalyst types. Maximum liquid product yields were obtained as 63.26 wt%, 56.18 wt%, and 54.59 wt% with the ZSM-5, Na2CO3 and sepiolite, respectively, at 10 wt% catalyst ratio. For all catalysts, it was determined that the liquid and solid yields reduce and the gas product yield rises with the catalyst ratio. The bio-oil characterization was performed with elemental analysis, FTIR, 1 HNMR, and GC-MS techniques. The bio-oil composition was determined to consist of alkanes, carboxylic acids, ketones, esters, benzenes, and phenols [ABSTRACT FROM AUTHOR]

Indole moiety is widely present in several natural bioactive products and medicinally important compounds. It is an essential scaffold for the development of novel leads. Nowadays, the synthesis of indoles by conventional methods is replaced with greener ones. The dynamic growth in green organic synthetic approaches for different heterocyclic scaffolds has markedly contributed to the field of medicinal chemistry over the last few decades. This review article compiled the last seven years' results in the green synthesis of indole and its derivatives using microwave irradiations from 2018 to 2024. Microwave (MW) assisted reactions are very rapid, environment-friendly, proficient, and convenient methodologies for the synthesis of organic compounds. This review contains synthetic procedures, reaction conditions, and greener features in synthesizing indole and its derivatives. This review article aims to promote greener synthesis methods and guide the researchers to design, develop, and synthesize indole-based derivatives using a microwave irradiation technique. This article also discusses the anticancer potential of indole-containing compounds reported in recent literature. [ABSTRACT FROM AUTHOR]

Organocatalysis is the use of non-stoichiometric amounts of low-molecular-weight organic molecules made up of C, H, N, O, S, and P to accelerate stereoselective chemical transformations. Despite having a long history, the use of small organic molecules as chiral catalysts in enantioselective synthesis has only recently intrigued scientists interest. However, in synthetic and medicinal chemistry, there has been a resurgence of interest in performing asymmetric synthesis of a variety of important targets by utilizing an organocatalytic approach as a leading reaction. The development of an asymmetric protocol for the synthesis of enantioenriched molecules of therapeutic relevance is crucial in the development of new drug candidates. Modern asymmetric catalysis is based on three pillars: (i) biocatalysts (i.e., enzymes), (ii) transition metal catalysis, and (iii) organocatalysis. Among these catalytic systems, organocatalysis has become the most flourishing field within the field of a catalytic regime that offers many significant benefits to synthetic and medicinal chemists. In contrast to many metal-based catalytic models, most organocatalysts have a high tolerance capability for air and moisture, easy availability, easy handling, non-toxic and enantiomeric purity, etc. They are often derived from natural resources of high enantiomeric virtue with the desired stereocentre or easily synthesized in the laboratory in some simple synthetic operations. This perspective aims to draw readers' attention to the power of asymmetric organocatalysis in assembling glycosyl donors and acceptors in the synthesis of biologically significant stereodefined O-glycosides. Glycosylation is a fundamental chemical transformation and is ubiquitous in both nature and chemical laboratories. In nature, the glycosylation processes are carried out by enzyme catalysis. We were interested in portraying the recent impressive progress achieved by the scientific community in the field of chemical glycosylation, specifically O-glycosylation. Poly-functionalized sugar moieties offer many opportunities to discover new drug candidates in which the modification of aglycone through the glycosylation process is a key reaction. [ABSTRACT FROM AUTHOR]

This study is a contribution to development of material based on transition metal oxides with application in electrochemical devices. A pyrochlore-like solid solution with general chemical formula Bi1.2Ce0.3Sb1.5CuO7 was synthesised. The pyrochlore structure was determined by X-ray powder diffraction. The pressed pyrochlore powder sample was analysed by scanning electron microscopy to show effect of substitution fraction of cerium and to determine its grain size and morphology. Energy dispersive of X-rays was performed to confirm effective substitution of bismuth for cerium. The EDX analysis was supported by X-ray photoelectron spectroscopy which also gave information on respective oxidation states of cations. Several modes of vibration due to metal-oxygen bonds of pyrochlore-like material were studied by Fourier-transform infrared spectroscopy. The results suggested that this compound contained major component of pyrochlore and minor component of CeO2. The dielectric measurements carried out at frequency 1 MHz in temperature range –40°C–90°C proved that pyrochlore compound possessed dielectric constants ranging between 12 and 28. Furthermore, owing to its high electrical conductivity, synthesised material has been utilised as bioanode in a microbial fuel cell. This bio-electrochemical device converted organic wastes into electricity using microorganisms as biocatalysts. It displayed greater electron transfer from electroactive biofilm towards the bioanode by improving its electrical energy output. The presence of pyrochlore in electrode allowed a power density of 25 mW/m2. It was almost the same as that obtained with a graphite carbon modified by the conducting polymer polypyrrole. The MFC with pyrochlore solid oxide was advantageously more stable having longer lifetime and indicating its suitability to substitute the polypyrrole at the bioanode. Besides, the colour of the coffee mac leachate in the anolyte (anode compartment) became less dark, which means that the maximum chemical oxygen demand (COD) was removed and converted into electric energy. [ABSTRACT FROM AUTHOR]

This review addresses the recovery of metals from all the main types of spent batteries (including Li-based, Zn-based, and Ni-based batteries) using bioleaching processes. Traditional processes are based on pyrometallurgical and hydrometallurgical methods and can be costly and, in some cases, cannot effectively recover the metals used in battery manufacture. Biobased hydrometallurgy may circumvent some of these drawbacks. This review presents a classification of batteries based on chemical composition from a recycling point of view. The bacterial and fungal leaching for each type of battery is reviewed. The research outputs are compared in each section, and chemical and biological mechanisms are presented. In addition, the catalytic effect of metals on the bioleaching process is reviewed for each battery. The results indicated that the main bioleaching mechanisms are the reactions of metals with metabolites, acid dissolution, and their combinations with oxidation-reduction reactions. The reactions presented in the literature are assessed and modified thermodynamically. The advantages and disadvantages of batteries bioleaching are discussed, and a future perspective is drawn. Although battery bioleaching has high efficiency and is an environmentally friendly method, with no gas emission and low energy consumption, slow kinetics and low pulp densities are among the major limiting factors hindering bioprocessing development from pilot to commercial scale. [ABSTRACT FROM AUTHOR]

In the present study, drinking water treatment sludge (DWTS) was reused as a catalyst in advanced oxidation processes for the removal of methylene blue (MB) from aqueous solutions. After determining their chemical and mineralogical compositions by X-ray Powder Diffraction (XRD), BET surface area, scanning electron microscopy with energy dispersive spectroscopy (SEM/ EDS), Inductively Coupled Plasma (ICP), and FT-IR spectra. DWTS has been used as a heterogeneous photo Fenton-Like catalyst for the oxidation of MB under different parameters, including pH (3-6), H2O2 concentration (9.79-29.37 mM), and dose (1-2.5 g/L). The results showed that within 180 min and under UV light irradiation, more than 86% of MB having a concentration of 50 mg/L were removed using a catalyst loading of 1.5 g/L, a H2O2 dosage of 23.17 mM and a solution pH of 5. The DWTS has a satisfactory stability as the catalyst is stable and have very less iron leaching property. [ABSTRACT FROM AUTHOR]

The heterogeneous catalysis of CO2 and H2 to CH3OH is a crucial technology for mitigating CO2 emissions and its promising application prospects have been driving extensive research. In this review, a wide variety of catalysts including copper, precious metal, typical metal oxides, and common metal-organic frameworks (MOFs) are systematically summarized. The corresponding reaction mechanisms are described. The status and prospect of industrial development in this field are discussed. Although the industrial scale of copper-based catalysts has been realized, the single-pass conversion rate is low and they are easy to deactivate. Intensive work is devoted to solving these problems by developing new catalysts. The excellent stability of more than 3000 hours and excellent low-temperature performances make MoS2 a promising catalyst. Much understanding has been obtained in various catalysts, though the mechanisms are ambiguous and molecular insights are still desperately needed. In the future, developing new efficient catalysts under low temperature with high stability is still the main concern in CO2 conversion system. [ABSTRACT FROM AUTHOR]

Cobalt Copper Zinc Ferrite (CoCuZnF) was synthesized using the co-precipitation method and characterized by various physicochemical instrumental techniques like UV-Vis, Raman, and N2-adsorption-desorption analysis to identify its structural parameters. Moreover, the catalytic study of nano CoCuZnF on ammonium perchlorate (AP) and AP-based composite solid propellant (CSP) was studied using DSC analysis. Furthermore, many kinetic models were employed to study its kinetics parameters. The thermal decomposition peak of AP was found to be decreased by 65–66°C in the presence of 1% by mass CoCuZnF additive. The activation energy of AP was found to be decreased by ~27-28% in the presence of CoCuZnF. The burn rate of AP-based CSP was found to be increased by 0.77 mm s−1 when CoCuZnF was used as an additive. [ABSTRACT FROM AUTHOR]

The main purpose of this work was proposing a versatile and capable method for the synthesis of diverse xanthenediones from the three-component condensation reaction of two moles of dimedone and one mole of various aldehydes by the lanthanum triflate catalyst in solvent-free conditions at 60 °C. The products were characterized by comparison of their melting points, IR, and NMR spectra with authentic samples. [ABSTRACT FROM AUTHOR]

In this work, the capability of step1 and step2 of the synthesis reaction mechanism of the 2-phenyl-1H-benzo[d]imidazole as a rate-determining step (RDS) has been energetically and thermodynamically evaluated using theoretical methods. The results were profoundly compared to the experimental approaches. The role of population explosion resulting from the increased hydroxyl groups within the catalyst structure was considered using some models with different hydroxyl groups on the reaction. Herein, the theoretical rate constants were obtained using the potential energy surfaces (PESs) and the transition state theory (TST) at the M06-2X/6-31 + G(d,p) level of theory. The calculated results showed that the second step (step2) is an RDS. In step2, H2O elimination can be proceeded by effective participation of catalyst for making a four-membered ring structure of TS that is generated harder than a six-membered ring mechanism (Ea = 56.3 and Ea = 29.7 kcal mol−1, respectively). Moreover, the reaction rate (for step2 as the RDS) in the presence of a modified catalyst (similar to sucrose containing five hydroxyl groups) speeds up 100,000 times more than the simple catalyst such as methanol (involving one hydroxyl group) and ethylene glycol (with the two hydroxyl groups). Theoretical calculations exhibited that the catalyst enables to facilitate a proton transfer process in step4 to make a great facility for doing oxidation process easily in step5 as the fastest step. In addition, when the reaction was followed without assisted-catalyst, herein, activation energy for step4 increased up to 34.8 kcal mol−1 while it was 10.8 kcal mol−1 in the presence of a catalyst. [ABSTRACT FROM AUTHOR]

Ruthenium-based compounds are efficient catalysts to enhance combustion performance and suppress soot emission. However, systematic mechanism and in-situ research on reducing soot are rarely addressed. In this study, ruthenium acetylacetonate (Ru(C5H7O2)3, Ru(acac)3) was utilized as the catalyst precursor in different concentration conditions to investigate its impacts on the size, volume, and morphology of the soot particles in the ethylene flames with central toluene injection. The soot particles were detected by in-situ small-angle X-ray scattering (SAXS) and ex-situ transmission electron microscopy (TEM). This study confirms that Ru(acac)3 can suppress the surface growth for the primary soot particles, but no significant change of the morphology has been discovered for the aggregates. Compared with the undoped flame, the volume of the soot particles in the Ru(acac)3-doped flames is lower and the particle size is smaller, indicating a valid inhibition effect of Ru(acac)3 on the soot emission by affecting its surface growth and oxidation process. Despite the remarkable distinction between the undoped and doped flames, no obvious difference is found between the flames with different catalyst concentrations. [ABSTRACT FROM AUTHOR]

The objective of this work is to recycle used engine oil until it is converted into an alternative fuel by catalytic pyrolysis. The effect of using eggshell ash as a catalyst in pyrolysis reactions on the yield of the resulting fractions was investigated. In addition, the influence of this catalyst on the compositions and the quality of the non-condensable gas and liquid fractions were analyzed. The results show that the liquid fraction recovered 97.02%wt; with 20%wt of the catalyst is predominant. The detection of aromatics 15.84%wt, olefins 32.74%wt, naphthenic 2.82%wt, paraffins 29.00%wt, and alcohols 20.50%wt, in the pyrolytic liquid and the observation of H2 15.22%wt, CH4 16.65%wt and other elements such as C4H8 21.93%wt in non-condensable gases, make it possible to predict the good usability of these products obtained as an alternative fuel. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the catalytic effect of sodium carbonate on tire pyrolysis oil (TPO) yield and composition when increasing the concentration of a catalyst in the feed material. The collected tire pyrolysis oil samples were analyzed using Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) and compared to diesel fuel. When the catalyst was introduced, the yield increased from 35 percent to 43 percent for the 10 percent catalyst. It was found from FTIR and GC-MS analyses that the TPO samples produced by both catalytic and thermal pyrolysis were complex mixtures of aliphatic, aromatic, nitrogen, and oxygen-containing compounds with carbon content ranging between C4 and C45 and there was an increase in branching with an increase in the catalyst. The TPO was found to contain aliphatic compounds that were similar to the ones contained in diesel fuel, indicating that the TPO contained some diesel. [ABSTRACT FROM AUTHOR]

Terrestrial environmental and biological systems are being threatened by the tremendous amount of human carbon dioxide emissions. Therefore, it is crucial to develop a sustainable energy system based on CO2 as chemical feedstock. In this review, an introduction to the CO2 activation and transformation has been made, together with a more comprehensive study of the catalytical reduction of CO2 to methane, methanol, and formic acid, which are currently contemplated as chemical feedstocks and/or promising energy carriers and alternative fuels. [ABSTRACT FROM AUTHOR]

After the successful removal of metals from printed circuit boards either through a physical or chemical process, epoxy resins are thermosetting plastics left over for landfilling. To overcome landfilling, thermal degradation of this resin was done under different particle sizes with varying catalyst concentrations. A series of thermogravimetric experiments were carried out using ZSM-5 as the catalyst. To study kinetics parameters' mass loss with temperature was divided into 3 zones 120–240°C, 240–360°C and 360–650°C. To determine activation energy and the order of reaction, the Coats and Redfern method was used. Experimental data in all three zones were found in agreement with the Coats and Redfern method. ZSM-5 was found to be reducing activation energy and the order of reaction in zone 2. The average activation energy was in the range of 150–200 kJ/mol and the order of reaction was 1.5–2 in zone 2 for different experiments. Coarser particles were found to have less decomposition than finer particles due to heat transfer limitation within the particle. However, the effect of increasing catalyst concentration was found ineffective in the mass transfer of more volatiles from PCB. [ABSTRACT FROM AUTHOR]

Cu with anthracene-2,3,6,7-tetramine ([CuAnTA·2H2O]n) as a recyclable metal-organic framework (MOF) was prepared and used for Pechmann reactions between different substituted phenols and ethyl acetoacetate to obtain coumarin derivatives in good to excellent yields. The prepared catalyst was characterized with various techniques such as FT-IR, XRD, SEM, EDX, BET, BJH and ICP-AES analysis. [CuAnTA·2H2O]n demonstrated good to excellent catalytic efficiency for Pechmann reactions in comparison with to other catalysts. Also, the catalyst is recovered by a simple filtration and reserved its activity even after several cycles. [ABSTRACT FROM AUTHOR]

\nIMPACT STATEMENTEnsuring the safety of researchers by protecting them from exposure to toxic gases in laboratories is of paramount importance. This study investigated the effectiveness of using high-surface-area MgO to remove HCl under atmospheric conditions. Two types of MgO were synthesized through the thermal decomposition of Mg(OH)2 and MgC2O4·2 H2O. HCl diluted with air passed through both MgO samples, and the amounts of HCl removed and morphological changes in the samples were compared. No significant differences in surface area or crystallinity were observed with the decomposition temperatures. X-ray diffraction analysis showed that the sample prepared from MgC2O4·2 H2O reacted with HCl immediately upon introducing HCl gas. In contrast, the sample obtained from Mg(OH)2 exhibited only MgO peaks, even 30 min after the introduction of HCl gas. Microscopic analysis revealed that the samples derived from Mg(OH)2 showed no significant changes in shape after the reaction, whereas the MgO prepared from MgC2O4·2 H2O exhibited substantial changes in overall shape. No correlation was observed between the surface area and the amount of HCl removed. When MgO is prepared from MgC2O4·2 H2O, the reaction occurs in the bulk material, whereas when MgO is prepared from Mg(OH)2, the reaction hardly progresses after HCl adsorbs onto the MgO surface. The order of magnitude of HCl removal was consistent with the base catalytic activity of the decomposition of diacetone alcohol to acetone. These results suggest that, compared with MgO obtained from Mg(OH)2, MgO derived from MgC2O4·2 H2O generates more active sites, resulting in the reaction with HCl from surface to progress into bulk.This study revealed that MgO derived from MgC2O4·2H2O generates more active sites that initiate the reaction with HCl under atmospheric conditions compared with MgO obtained from Mg(OH)2 [ABSTRACT FROM AUTHOR]

Lignosulfonate is an efficient biomass-based building block, formed an efficient Fe3O4@LS nanocomposite with enormous applications. Concerning environmental and economic aspects, our research focused on the application of Fe3O4@LS nanocomposite as the metal-free catalyst in the synthesis of 4H-pyrans and 4-phenyl-pyridines. The structure and morphology of Fe3O4@LS nanocomposite were completely characterized by Fourier transforms infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX) field emission scanning electron microscopy (FE-SEM), vibration-sample magnetometer (VSM), X-ray diffraction (XRD) thermal gravimetric analysis (TGA) and back titration method. Also, the structure of synthesized 4H-pyrans and 4-phenyl-pyridines were characterized by FTIR, nuclear magnetic resonance (NMR), and their melting points. This procedure has significant advantages included into high yields, short reaction time and easy operation. [ABSTRACT FROM AUTHOR]

For cost-effective biodiesel synthesis, a solid heterogeneous acid catalyst SO3H-ARNH-12 was synthesized by sulfonation of activated carbon derived from areca nut husk (ARNH). SEM-EDS, XPS, FTIR, and XRD analyses investigate the morphology and elemental composition that reveals the successful sulfonation of carbonaceous material. The SO3H-ARNH-12 provides an excellent conversion of 99.15 ± 0.4% in a short reaction time (30 min) under various optimized conditions {catalyst dose 7 wt.%, 100°C temperature, 1:10 Oleic acid-to-MeOH ratio (OATMR)}. It has been investigated that different types of alcohols affect the biodiesel yield. Moreover, the biodiesel yield was established by GC analysis, and confirmation of biodiesel synthesis was done by 1H, 13C NMR spectroscopy. The effective catalytic activity of the catalyst was observed for up to six cycles. This work provides a sustainable heterogeneous acid catalyst for the fabrication of biodiesel, which solves pollution, time, and energy consumption issues. [ABSTRACT FROM AUTHOR]

The CoxOy/AC catalysts were prepared by wet impregnation method for toluene oxidation removal from air. The thermal stability of cobalt nitrate and Co oxide on the activated carbon (AC) support surface was analysed by thermal analysis. The physicochemical properties of the prepared catalysts were characterised by XRD, SEM, H2-TPR, and XPS. AC support with high specific surface area and developed pore structure can promote the dispersion of Co species on its surface to form highly dispersed Co oxide species. The participation of AC supports can promote the partial reduction of Co3O4 species to CoO species to coexist in the prepared CoxOy/AC catalyst. The Co2+/Co3+ ratio was significantly affected by the calcination temperature, and the appropriate Co2+/Co3+ ion pairs in the studied CoxOy/AC catalyst is helpful to the activity of O2 molecules to form reactive oxygen species. The oxygen species composition on the catalyst surface is obviously affected by the calcination temperature, which plays an important role in toluene oxidation reaction. The studied CoxOy/AC catalysts exhibited excellent toluene oxidation removal performances. The conversion of toluene exceeded 97% and 99% at 240°C and 250°C, respectively, and maintained good stability within 700 min. That is to say, the concentration of toluene in the air can be reduced from 10,000 ppm to less than 40 ppm by using the CoxOy/AC catalyst. [ABSTRACT FROM AUTHOR]

Knoevenagel condensation was optimized through the eco-friendly condition as a binary mixture of ethanol:water (3:7, v/v) associated with NaCl salt as the promoter of the reaction between different aldehydes or isatins and malononitrile at room temperature. Due to its high efficiency and low toxicity, the proposed system provides easy isolation of products by simple filtration and optimal yields ranging between 83 and 97% in a short-time reaction at room temperature. [ABSTRACT FROM AUTHOR]

This study aims to investigate the potential of zeolitic based catalysts for biodiesel production from waste sunflower vegetable oil. The zeolite-based catalyst was prepared by two impregnation steps. The obtained catalyst was examined for the transesterification reaction. The effect of operating variables and the synergetic effects between those variables were investigated. Other parameters such as catalyst impregnation time, stirring speed and catalyst particle size were also studied. Furthermore, the physical and chemical properties of the oil and the produced biodiesel were measured. Nearly complete 100% conversion and 96.7% yield were achieved using 11.5 MeOH/oil molar ratio, 6.4% catalyst dosage, at 50°C reaction temperature and reaction time of 2 hours. The properties of the obtained biodiesel are in agreement with the values specified by US and EU standards. [ABSTRACT FROM AUTHOR]

In this paper, sugarcane bagasse was used as the raw material to produce hydrochar (HC) through the hydrothermal carbonization (HTC) process, then Ni and Mg were loaded on HC by the impregnation method. Thus, a serial of Ni-Mgx@HC core-shell structural catalysts for CO2 dry reforming were synthesized. In order to evaluate the application of Ni-Mgx@HC catalyst derived from sugarcane bagasse, the catalytic performance for CO2 dry reforming were investigated. Experimental results showed that the hydrochar based catalyst (Ni-Mg15@HC) exhibited an excellent activity and stability at 750°C, CH4 and CO2 conversions were 63.7% and 76.9%, respectively. XRD, TEM, CO2-TPD and TG-DTG characteristic proved that the addition of Mg into Ni@HC would promote the active site formation and the adsorption capacity of CO2. Moreover, the coke deposition was also suppressed in the DRM process. The catalytic performance of Ni-Mg15@HC catalyst demonstrated that it was a practical candidate for the DRM reaction due to its unexpected activity and stability. [ABSTRACT FROM AUTHOR]

In this research, the phosphotungstic acid (PTA) was impregnated on natural zeolites of clinoptilolite (Clin), mordenite (Mord), ferrierite (Ferr), and natrolite (Nat) and was characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX. The synthesized heterogeneous nanocomposites were used for oxidative desulfurization of dibenzothiophene (DBT). Among samples, PTA-Ferr has removed the most amount of DBT (82.02%) from model fuel and PTA-Nat, PTA-Clin, and PTA-Mord indicated 56.00%, 73.62%, and 67.05% removal of initial DBT, respectively. PTA-Ferr had a high surface area of 293.6 m2/g, agglomeration-free particles with an average size of 10.2 nm. To study the effect of operating parameters such as reaction time, reaction temperature and DBT concentration on the ODS activity of PTA-Ferr, a central composite design (CCD) was used. Optimized conditions for the highest DBT removal (94.39%) were obtained at a reaction time of 55 min, the temperature of 60 °C and a DBT concentration of 250 ppm. [ABSTRACT FROM AUTHOR]

The formation of phenoxy radicals that scavenge free radicals is critical for improving the antioxidant activity of lignin. Novel modified lignin with high phenolic hydroxyl content and enhanced antioxidant properties was prepared from kraft lignin using a two-step method. First, diethylenetriamine-modified amine lignin (DAL) was synthesized via the Mannich reaction. Second, the DAL was reacted with 3,4-dihydroxyhydrocinnamic acid (DHCA) using N-hydroxysuccinimide as the catalyst. The DHCA-modified DAL (DDAL) was characterized and tested for the removal of 1,1-diphenyl-2-picrylhydrazyl (DPPH) from aqueous solutions. The optimum conditions were as follows: a reaction temperature of 80 °C, a 1:1 mass ratio of DHCA to DAL, and a catalytic time of 2 h. The phenolic content of DDAL increased from 0.81 to 1.51 mmol/g. More importantly, the DPPH free radical scavenging capacity of DDAL reached 79.94% at a concentration of 0.50 mg/mL. This study provides a practical strategy for preparing high-performance bio-based antioxidants. [ABSTRACT FROM AUTHOR]

The increase of motor vehicles results in a rapid increase in fuel supply and generates high emissions, which then affects the environment and human health in general. Replacement of nonrenewable fuels can be achieved by using alternative energy sources. Viewing fuel properties and production routes, biodiesel is deemed as one preferred alternative fuel for diesel engines. This work focuses on biodiesel production using waste cooking oil through a catalyst made of mixed multi-fruits' peel ash and titanium dioxide nanoparticles through a transesterification process. Further, the produced biodiesel was used to evaluate the engine performance by analyzing brake thermal efficiency and brake-specific fuel consumption. Emission characteristics due to biodiesel combustion, namely carbon monoxide and nitrogen oxides, was our main focus in this study. Both engine performance and emissions levels were optimized through Taguchi L16 orthogonal array. Highest brake thermal efficiency of 36.19% was achieved by the influence of 450°C of calcination temperature, 30°C of reaction temperature, 4% of catalyst loading, and 3 hr time of reaction. The lowest brake-specific fuel consumption obtained is 0.23 kg/kWh by involving 300°C of calcination temperature, 60°C of reaction temperature, 4% of catalyst loading, and 5 hr time. The statistical analysis based on ANOVA shows that the studied parameters does contribute to the developed regression model. In emission analysis, calcination temperature greatly influenced both CO and NOx. [ABSTRACT FROM AUTHOR]

This work reports on the ability of Clitoria ternatea aqueous flower extract to prepare biogenic silver nanoparticles (AgNPs). The obtained AgNPs were used as efficient nanocatalysts for the elimination of methyl orange, a carcinogenic azo dye, from an aqueous solution. Several parameters that affected the AgNPs formation were examined. The prepared AgNPs were characterised by UV-Vis spectroscopy, FTIR, SEM-EDX, XRD, TEM, and zeta potential. The formation of AgNPs was confirmed by the development of yellowish-brown colour which was further proved by a surface plasmon peak at 430 nm in UV-Vis spectroscopy. FTIR analysis revealed that anthocyanin present in the extract might be responsible for the reduction of Ag+ to AgNPs and capping the particles. Production of stable, well-dispersed face centred cubic spherical crystalline particles with diameters in the range of 10–30 nm was obtained from XRD and TEM studies. SEM-EDX result affirmed the silver content of 73.7%, and zeta potential measurement showed excellent stability of AgNPs with high negative values of −27.77 ± 1.51 mV. Further, the AgNPs catalyst exhibited the excellent catalytic performance in the degradation of methyl orange dyes by NaBH4. The degradation process was completed within 10 min, together with a constant rate value of 0.3285 min−1. The results show strong potential of the biosynthesised AgNPs as a candidate for use in environmental remediation. [ABSTRACT FROM AUTHOR]

Present work reports the newly synthesized resin polymethylene, bis-2-methoxy-1-napthaldehy-o-phenylenediimine (PMBMNOPhen) and then react with titanium dioxide and silicon dioxide to form encapsulated resin by metal oxide nanoparticles (PMBMNOPhenTiO2/SiO2) and resulted in the material is polymethylene, bis-2-methoxy-1-napthaldehy-o-phenylenediimine titanium-dioxide nanoparticles (PMBMNOPhenTiO2). The resin-encapsulated metal oxide nanoparticles were successfully identified morphology, crystal structure, and light absorption capacity of samples were characterized via scanning electron microscope (SEM), X-ray diffraction, energy dispersive (EDS) X-ray diffraction analysis (XRD) and ultraviolet–visible spectroscopy methods. Afterwards, the resin-encapsulated metaloxide nanoparticles are used for degradation of methylene orange (MO) dye. The photo-oxidation rate of the dye is dependent on the different parameters: initial dye concentration, effect of time, the effect of NaBH4 and effect of dose of catalyst. The degradation of MO 60–80%% in real water samples with respect time of 30–60 minutes. These results confirm the prepared resin-encapsulated titanium dioxide nanoparticles (PMBMNOPhenTiO2/SiO2) displaying a great photocatalytic activity for the degradation of methylene orange dye under visible light irradiation effect of a catalyst in real water sample degradation. The synthesized catalyst (PMBMNOPhenTiO2/SiO2) was successfully applied in real dye water solution (colored water), collected from Jamshoro, Sindh (Pakistan). The resin-encapsulated metal oxide nanoparticles showed an excellent performance to reduce MO dye in contaminated water. These results approve that the resin-encapsulated titanium dioxide nanoparticles (PMBMNOPhenTiO2) display a great photocatalytic activity for the degradation of MO dye under visible light irradiation degradation. Photocatalytic degradation using resin-encapsulated (TiO2/SiO2) catalyst is effectively used for the textile dye (MO). [ABSTRACT FROM AUTHOR]

A simple low-cost one-pot photodeposition synthesis with no hazardous reactants or products is used to make silver nanoparticles-activated carbon composite (SNPs@AC). The SNPs are homogenously and photodeposited and absorbed into the activated carbon matrix. Both SNPs and SNPs@AC composite have particle sizes around 10 nm and 100 nm, respectively. The SNPs@AC composite showed good antiviral activity to VERO (ATCC ccl-81) cells. Zeta potential of SNPs@AC composite is −25 mV, showing that this colloidal system is electrically stable and resistant to coagulation. For many Gram-positive and Gram-negative bacteria, the SNPs@AC composite demonstrated strong antibacterial efficacy. The SNPs@AC composite has 75.72 percent anti-inflammatory effect at concentration 500 µg/mL. This composite has a maximum non-toxic concentration (MNTC) of 78.125 g/mL, which corresponds to antiviral activity of up to 96.7 percent against hepatitis A. virus (HAV). It is suggested as a candidate for pharmaceutical formulations, such as integration into the manufacture of N95 masks for COVID-19 infection protection. Concentration 160 μg/mL SNPs@AC composite has antioxidant activity 42.74% percent. The SNPs@AC composite exhibited selective catalytic activity for the organosynthesis hydrazination reaction of 4-chloro-3, 5-di-nitro-benzo-triflouride, giving 1-hydroxy-4-nitro-6-trifluoro-methyl benzotriazole, a common antiviral drug for severe acute respiratory syndrome (SARS). SNPs@composite's well-defined pores provide suitable active sites for binding reactants: 4-Cl-3, 5-di-NO2-benzotriflouride, and hydrazine, which react to create 1-hydroxy-4-nitro-6-trifluoromethyl benzotriazole, which diffuses into solution away from the catalyst surface, leaving the catalyst surface unaffected. [ABSTRACT FROM AUTHOR]