Green Synthesis Method Research Articles

Green Synthesis of Luminous Indium Phosphide Nanocrystals.

Indium phosphide (InP) nanocrystals (NCs) have garnered significant attention for displays and bioimaging due to their superior optical properties and low toxicity. However, the high cost and operational risks associated with the colloidal synthesis of InP NCs hinder their widespread development and application. In this study, we presented a green synthesis method for InP NCs using solid ammonium hypophosphite ((NH4)H2PO2) as an economical and safe phosphorus precursor. (NH4)H2PO2 was decomposed controllably to produce highly reactive gaseous phosphine (PH3) through precise temperature management. The released PH3 then reacted with indium carboxylate to form InP clusters, which serve as intermediate precursors. This cluster-assisted method endowed a continuous supply of monomers for the nucleation and growth of high-quality InP NCs with uniform size distribution. Following a surface treatment that balances etching and passivating capabilities, the InP NCs exhibited a narrow emission line width of 46 nm and a near-unity photoluminescence quantum yield (PLQY), representing one of the best emission performances for shell-less InP NCs. The economical and stable nature of the raw materials used in this approach opens a pathway for the green synthesis of InP NCs.

Potential of Green Gold Nanoparticles Synthesized from Punica granatum Extract on Leishmaniasis and Breast Cancer Treatment

AbstractIn the current study, the physicochemical properties and biological activities of gold nanoparticles (AuNP) synthesized in small sizes by Punica granatum using the green synthesis method and the chemical method were compared. UV–vis peak of chemically and biologically synthesized AuNPs was confirmed at 540 nm and 535 nm, respectively. By FT‐IR analysis, it was revealed that there were active biomolecules in Punica granatum extract for the synthesis of green AuNPs. According to XRD results, broad spectra were obtained. The crystalline nature of Green AuNP was demonstrated. Using SEM and DLS, it was observed that green AuNP had dimensions between 4–6 nm and chemical AuNP had dimensions between 6–12 nm. Punica granatum‐based AuNPs were more effective in the MDA‐MB‐231 breast cancer cell line than AuNPs by chemical method. It has also been revealed that green AuNPs are much more effective than chemical AuNPs against L. infantum parasites. As a result, Punica granatum‐based green AuNPs have been proven to be functionally more efficient and effective than chemically prepared AuNPs. Our study will encourage researchers to increase the synthesis of green NPs for medical use.

Green synthesis of silica-coated gold nanoparticles employing femtosecond laser, solid targets, and water

Gold nanoparticles are widely used in biomedical applications due to their unique properties. However, traditional synthesis methods generate contaminants that cause cytotoxicity and compromise the biocompatibility of the nanomaterials. Therefore, green synthesis methods are essential to produce pure and biocompatible nanoparticles, ensuring their effectiveness in biomedical applications. This study introduces a novel approach for synthesizing silica-coated gold nanoparticles (AuNP@SiO₂) using femtosecond laser ablation in water, eliminating the need for chemical reagents. The process involves three key laser-based steps: Si ablation, SiNP@SiO₂ fragmentation, and Au ablation, all conducted in a liquid environment. The resulting AuNP@SiO₂ were characterized using transmission electron microscopy (TEM), UV–Vis absorption spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), and zeta potential measurements. The results demonstrated that the AuNP@SiO₂ nanoparticles exhibit high colloidal stability, with a notably negative zeta potential of (-72.0 ± 0.3) mV, effectively preventing particle aggregation. TEM analysis confirmed predominantly spherical nanoparticles with an average diameter of (15.87 ± 0.70) nm, encapsulated by a SiO₂ layer ranging from 1 to 3 nm in thickness. The synthesis approach produced nanoparticles with an average size distribution below 35 nm. This green synthesis method not only produces stable and well-characterized AuNP@SiO₂ nanoparticles but also represents a significant step towards more sustainable nanomaterial production, with promising implications for biomedical applications.

Green Catalysts AuNPs/CQDs From Turmeric Starch: An Effective Solution in 4-Nitrophenol Reduction

Abstract This paper presents a green synthesis method for growing carbon quantum dots (CQDs) from turmeric starch. The CQDs were then used as reducing agents and stabilizers to synthesize dual-shaped gold nanoparticles (AuNPs) with spherical and triangular shapes. In addition to the advantages of CQDs in catalysis, such as large surface area, many functional groups, and excellent electron transfer ability, the obtained AuNPs/CQDs nanocomposite material benefits from the plasmonic properties of AuNPs, which enhance the light absorption ability and accelerate the catalytic reactions. This material has been applied to effectively catalyze toxic 4-nitrophenol (4-NP) in aqueous media with high efficiency. The synergy between the plasmonic effect of AuNPs and the catalytic properties of CQDs results in a high catalytic efficiency and a fast reaction time of 20 min, making this method simple, rapid, scalable, and highly effective for environmental pollution remediation.

Sustainable Synthesis of Zirconium Dioxide (ZrO2) Nanoparticles Utilizing Asphodelus fistulosus Extract for Congo Red Degradation

This research presents a green approach to synthesizing zirconium oxide (ZrO2) nanoparticles using an Asphodelus fistulosus plant extract as a reducing and stabilizing agent. The synthesized ZrO2 nanoparticles were characterized using various advanced techniques. The XRD pattern provides different forms of ZrO2, like tetragonal and cubic forms, and the results confirmed the successful formation of crystalline ZrO2 nanoparticles with a definite morphology. The XPS data exhibit that the bioactive chemicals present in the extract, including polyphenols, flavonoids, and reducing sugars, perform the functions of reducing and capping agents. Additionally, CR dye molecules may create hydrogen bonds with these surface moieties, which are approved by FTIR. These interactions may assist in aligning dye molecules with catalytically active regions on ZrO2 surfaces and may interact with photogenerated species. The catalytic activity of the synthesized ZrO2 nanoparticles was evaluated for the degradation of Congo red dye under ultraviolet irradiation. The nanoparticles exhibited excellent photocatalytic activity, degrading a significant amount of the dye within a short period. Various parameters were investigated to optimize the photodegradation process, including irradiation time, catalyst dosage, pH, and initial dye concentration. The optimal conditions were determined to be a pH of 7, a catalyst loading of 20 mg/L, and an irradiation time of 75 min, resulting in a remarkable ≈92% degradation efficiency. This green synthesis method offers a sustainable and eco-friendly alternative to conventional chemical methods for producing ZrO2 nanoparticles, which have potential applications in environmental remediation.

Comparative Study of the Synthesis of Silver, Copper, and Iron oxide Nanoparticles via Chemical and Green Methods Using Corn Bract for Enhanced Antibacterial Activity

The increasing demand for sustainable and eco-friendly solutions in nanotechnology highlights the importance of exploring novel methods for the synthesis of nanoparticles. Metal nanoparticles have unique properties and are particularly significant in addressing antimicrobial resistance and environmental challenges. This study aimed to synthesize silver, copper, and iron nanoparticles from waste corn bract using chemical and green synthesis methods and evaluate their antibacterial properties. Corn bract extract was prepared and used as a reducing and stabilizing agent in green synthesis, while the comparison was done by conventional chemical methods. The nanoparticles were characterized using UV-visible spectroscopy, FTIR, and SEM, and their antibacterial activity was tested against Gram-positive (Bacillus sp., Staphylococcus sp.) and Gram-negative (Escherichia coli, Klebsiella sp., Pseudomonas sp.) bacteria through the well diffusion method. The green-synthesized silver nanoparticles exhibited the highest antibacterial efficacy, especially against Pseudomonas sp. and E. coli, followed by copper and iron nanoparticles. Phytochemicals in corn bract extract enhanced the stability and bioactivity of green-synthesized nanoparticles, as confirmed by FTIR analysis. The results of this investigation underscore the capabilities of agricultural waste in facilitating sustainable nanoparticle production, wherein green synthesis provides enhanced antibacterial attributes in comparison to traditional chemical approaches. This research emphasizes the significance of nanoparticles synthesized through green methods in addressing antimicrobial resistance and highlights their role as a scalable and environmentally sustainable option for generating effective antimicrobial agents.

Characterization, Antibacterial Activity, and Dye Removal Capacity of Green and Hydrothermal Green Synthesized ZnO Nanostructures Using Crataegus Orientalis

AbstractIn this study, the cost‐effective and environmentally friendly green synthesis of zinc oxide (ZnO) nanostructures is reported using Crataegus orientalis fruit extract with green synthesis (GS) and hydrothermal‐assisted green synthesis (HTGS) methods. The optical, structural, and morphological characteristics of the synthesized ZnO nanostructures are examined by UV–vis Spectroscopy (UV–vis), X‐ray diffraction (XRD), and field emission scanning electron microscopy (FE‐SEM) supported with energy dispersive X‐ray spectroscopy (EDX). XRD patterns confirmed that the synthesized ZnO nanostructures have a hexagonal single phase. The average crystallite size and optical bandgap values are obtained as 31 and 27 nm, 2.8 and 3.02 eV, for GS‐ZnO and HTGS‐ZnO nanostructures, respectively. The synthesized HTGS‐ZnO and GS‐ZnO nanostructures are used as a catalyst in the photodegradation of methylene blue (MB) dye and show excellent degradation activity of 99% after 120 min of UV illumination. In addition, it is found that HTGS‐ZnO and GS‐ZnO nanostructures have a higher antibacterial effect against Staphylococcus aureus ATCC 25923 than ZnO nanostructures synthesized by chemical methods. Moreover, since both synthesis methods show similar results, the GS method, which is lower cost, simpler, and less time‐consuming than the HTGS technique, can be recommended to synthesize ZnO nanostructures using Crataegus orientalis.

Pseudomonas monteilii ZMU-T06 produces 2-substituted quinolines by oxidative dehydroaromatization

2-substituted quinolines are the building blocks for the synthesis of natural products and pharmaceuticals. In comparison with classical methods, dehydroaromatization of 2-substituted-1,2,3,4-tetrahydroquinolines has emerged in recent years as an efficient and straightforward method to synthesize quinolines due to its high atom economy and sustainability. However, existing chemical methods need transition metal catalysts and harsh reaction conditions. Biocatalysis with high efficiency, high selectivity, and mild reaction conditions has become an important method of organic synthesis. We mined a strain Pseudomonas monteilii ZMU-T06 capable of producing monoamine oxidase for the dehydroaromatization of 2-substituted-1,2,3,4-tetrahydroquinolines to synthesize 2-substituted quinolines (8 substrates, yields of 45.7%-48.4%) and then hypothesized the catalytic mechanism, providing a new method for green synthesis of 2-substituted quinolines.

Characterization, synthesis, and biological activities of silver nanoparticles produced via green synthesis method using Cordyceps militaris aqueous extract

Characterization, synthesis, and biological activities of silver nanoparticles produced via green synthesis method using <i>Cordyceps militaris</i> aqueous extract

Luminescence Characterization of the Green Synthesized Terbium Doped Titanium Oxide

Purpose: The purpose of this work is to prepare Titanium Oxide (TiO₂) with eco-friendly synthesis and also to study on structural, morphological, photoluminescence properties on Tb doped TiO₂. Methodology: Titanium Oxide was prepared by orange fruit aqueous extract as a reducing agent with addition of terbium as its dopant. Characterization of the synthesized TiO₂ was done by XRD proving that the TiO₂ was in the structural form of rutile as evidenced by the sharp peaks. The relationship between the concentration of Tb dopant and the grain size of the film layer was studied. SEM Morphological analysis indicated the formation of particle cluster at 1100°C. EDX spectroscopy was employed to determine the position of elements of the samples while FTIR spectroscopy was in agreement with carbonyl and hydroxyl groups being absent in the prepared samples. Optical characteristics of the samples were evaluated by photoluminescence measurements under the excitation of 400 nm wavelength. Findings: The results obtained in the present study pointed out how the terbium doping affected the structural and optical characterization of the TiO₂. An increase in the Tb concentration led to an increase in the grain size of the synthesized spherical film. Photoluminescence spectroscopy results showed two separate green and red emissions and was measured to have the highest intensity at 4% terbium concentration. From these results we can see the prospect of using Tb-doped TiO₂ in applications that require certain changes in the optical parameter. Contribution to Theory, Policy, and Practice: This work contributes to the body of knowledge on green synthesis methods for nanostructures and the effect of RE doping in improving the properties of a material. The results provide insight for green synthesis of photo luminescent materials, optoelectronic devices, and monitoring instruments, identifying ways to pursue environmentally friendly material design.

Phytochemical analysis and biological activities of solvent extracts and silver nanoparticles obtained from Woodwardia unigemmata (Makino) Nakai.

Multidrug resistant bacteria are causing health problems and economic burden worldwide; alternative treatment options such as natural products and nanoparticles have attained great attention recently. Therefore, we aimed to determine the phytochemicals, antibacterial potential, and anticancer activity of W. unigemmata. Extracts in different organic and inorganic solvents were prepared, silver nanoparticles were prepared using the green synthesis method. Phytochemicals and antioxidant activity was determined spectrophotometry, anticancer potential was determined against gastric cancer and normal gastric epithelial cells using CCK8 and colony formation assays W. unigemmata was found to have a significant enrichment of various phytochemicals including flavonoids, terpenoids, alkaloids, carotenoids, tannins, saponins, quinines, carbohydrates, phenols, coumarins and phlobatanins. Among them phenolics (5289.89 ± 112.67) had high enrichment followed by reducing sugar (851.53 ± 120.15), flavonoids (408.28 ± 20.26) and ascorbic acid (347.64 ± 16.32), respectively. The extracts prepared in organic solvents showed strong antibacterial activity against P. aeruginosa (chloroform, 13.66±0.88, ethyl acetate, 8.66±4.33, methyl alcohol, 13.33±1.66, N-hexane, 12.33±0.88) and S. aureus (chloroform, 15±0.57, ethyl acetate, 16.33±0.33, methyl alcohol, 17.66±0.33 and N-hexane, 16.33±0.33). Aqueously prepared AgNPs showed remarkable activity against P. aeruginosa follwed by E. coli, 17.66 ± 1.85, S. aureus, 16.00 ± 1.73, K. pneumoniae, 14.33 ± 1.20, respectively. The ethanolic extracts (500 μg, 1000 μg, 2000 μg) of the W. unigemmata were found to have cytotoxicity against both gastric cancer (AGS and SGC7901) and normal cell lines (GES-1); a significant cellular proliferation arrest was observed. These results suggest that W. Unigemmata contains numerous bioactive phytochemicals and can be useful as a drug against MDR bacterial strains. These biomolecules covering AgNPs may enhance their biological activities, which can be employed in the treatment of various microbial infections.

Revolutionizing radiotherapy: gold nanoparticles with polyphenol coating as novel enhancers in breast cancer cells—an in vitro study

Breast cancer is the most common cancer among women, with over 1 million new cases and around 400,000 deaths annually worldwide. This makes it a significant and costly global health challenge. Standard treatments like chemotherapy and radiotherapy, often used after mastectomy, show varying effectiveness based on the cancer subtype. Combining these treatments can improve outcomes, though radiotherapy faces limitations such as radiation resistance and low selectivity for malignant cells. Nanotechnologies, especially metallic nanoparticles (NPs), hold promise for enhancing radiotherapy. Gold nanoparticles (AuNPs) are particularly notable due to their high atomic number, which enhances radiation damage through the photoelectric effect. Studies shown that AuNPs can act as effective radiosensitizers, improving tumor damage during radiotherapy increasing the local radiation dose delivered. Traditional AuNPs synthesis methods involve harmful chemicals and extreme conditions, posing health risks. Green synthesis methods using plant extracts offer a safer and more environmentally friendly alternative. This study investigates the synthesis of AuNPs using Laurus nobilis leaf extract and their potential as radiosensitizers in breast carcinoma cell lines (MCF-7). These cells were exposed to varying doses of X-ray irradiation, and the study assessed cell viability, morphological changes and DNA damage. The results showed that green-synthesized AuNPs significantly enhanced the therapeutic effects of radiotherapy at lower radiation doses, indicating their potential as a valuable addition to breast cancer treatment.

Green Synthesis of Tetrahydropyrazino[2,1-a:5,4-a']diisoquinolines as SARS-CoV-2 Entry Inhibitors.

A class of tetrahydropyrazino[2,1-a:5,4-a']diisoquinoline derivatives were synthesized under environmentally friendly conditions using water as the solvent. The 3-D structures of some synthesized compounds were determined by X-ray diffraction. Since naturally occurring isoquinoline alkaloids have significant antiviral activities against a wide range of viruses, including coronaviruses, the synthesized compounds were assayed for their inhibitory activities against SARS-CoV-2. Our results showed that the active compounds 50 and 96 blocked the delta SARS-CoV-2 entry into VeroE6 cells to display EC50 of 26.5 ± 6.9 and 17.0 ± 3.7 μM, respectively, by inhibiting the interaction between SARS-CoV-2 Spike's receptor binding domain (RBD) and human receptor angiotensin-converting enzyme 2 (ACE2), and CC50 greater than 100 μM. This study provides a green synthesis method of tetrahydropyrazinodiisoquinoline for antiviral or other applications.

Green Ferrites: Eco‐Friendly Synthesis to Applications in Environmental Remediation, Antimicrobial Activity, and Catalysis—A Comprehensive Review

ABSTRACTFerrite magnetic materials have emerged as capable materials in engineering, research, and medicine because of their exclusive and fascinating properties obtained from a variety of synthesis techniques. These ferrites are significant in commercial products, research, and biomedical applications. Green synthesis methods for ferrite nanocomposites and nanoparticles are becoming increasingly popular due to their usefulness in a range of industries, engineering, environmental, and medicinal remediation. Ferrite nanoparticles and nanocomposites (MFe2O4, where M = Ni, Cu, Mg, Co, Zn, and Mn) have recently gained popularity due to their many uses in biological, environmental, and chemical interactions. This review covers the most recent investigations over the last few years on green‐synthesized ferrite nanoparticles, ferrites containing nanocomposites, and more elements, with a focus on microorganism‐mediated and plant‐based synthesis processes. The surface features of ferrite nanoparticles synthesized from green materials are discussed, as is their potential for sensors, energy, water treatment, antibacterial activity, biological, and heavy metal removal applications. This article presents an inclusive overview of green‐synthesized ferrites, including the most recent research advances and findings. To fully realize the promise of nanoferrites in several fields, a thorough understanding of green manufacturing, properties, and applications is essential. Green‐synthesized ferrites are chosen due to their potential for improved control over particle size and shape, lower cost, decreased toxicity, and environmental friendliness, all of which preserve magnetic properties that are better than those of conventionally synthesized ferrites, making them a more sustainable choice for a range of applications.

Study on the Role and Pathological and Immune Responses of Silver Nanoparticles Against Two Aeromonas salmonicida subsp. salmonicida Strains at Different Virulence Levels in Rainbow Trout (Oncorhynchus mykiss)

Aeromonas species are among the main pathogens causing rainbow trout infections. Silver nanoparticles (AgNPs) have a broad spectrum of antimicrobial properties and are usually produced by various green-synthesis methods. However, the application of commercialized AgNPs has not fully been clarified. Thus, the objective of this study was to evaluate the antibacterial activities of commercialized AgNPs (range of sizes 10–12 nm) on two contrasting A. salmonicida strains (I-1 and I-4), isolated from rainbow trout; the antibacterial mechanism, histopathological alterations and the expression of immune-related genes were investigated. In vitro, the minimal inhibitory concentration (MIC) was 10 µg/mL for I-1, and lowered to 9.5 µg/mL for I-4, respectively. AgNPs were shown to disrupt both the cell wall and membrane of I-1 and I-4, resulting in cell lysis and degradation. In vivo, rainbow trout challenged by immersed or intraperitoneally injected infection, the 10 µg/mL AgNP-treated groups, both showed delayed deaths and lower mortalities compared to the control groups, without any clinical signs and pathological changes. Especially for the virulent I-4, the enhanced expressions of immune-related genes TNF-α, IL-1β, IL-10 and IL-11 were significantly reduced in the AgNP-treated group, indicating a lesser inflammation due to the application of AgNPs. This study would lay theoretical foundation for the wide application of silver nanoparticles in fish diseases.

Advances of Hydroxyapatite Nanoparticles in Dental Implant Applications.

Hydroxyapatite nanoparticles (HANPs) are becoming increasingly crucial in dental implant applications as they are highly compatible with biological systems, actively support biological processes, and closely resemble bone minerals. This review covers the latest progress in how HANPs are made, studied, and used in dentistry. It looks at critical methods for creating HANPs, such as sol-gel, microwave hydrothermal synthesis, and biomimetic approaches, and how they affect the particles' size, structure, and activity. The green synthesis method illustrated a new door to synthesize HAp for maintaining biocompatibilityand increasing antibacterial properties. The review also explores how HANPs improve the integration of implants with bone, support bone growth, and help treat sensitive teeth based on various laboratory and clinical studies. The usage of HAp in dentin and enamel shows higher potentiality through FTIR, XPS, XRD, EDS, etc., for mechanical stability and biological balance compared to natural teeth. Additionally, the use of HANPs in dental products like toothpaste and mouthwash is discussed, highlighting its potential to help rebuild tooth enamel and fight bacteria. There are some challenges for long-term usage against oral bacteria, but doping with inorganic materials, like Zn, has already solved this periodontal problem. Much more research is still essential to estimate the fabrication variation based on patient problems and characteristics. Still, it has favorable outcomes regarding its bioactive nature and antimicrobial properties. Due to their compatibility with biological tissues and ability to support bone growth, HANPs hold great promise for advancing dental materials and implant technology, potentially leading to better dental care and patient outcomes.

Investigation of Magnetism and Photocatalytic Activity Using Biomass‐Derived Carbon Dots

AbstractA cost‐effective and green synthesis method was adopted for the synthesis of carbon dots (CDs) using easily available biomass, namely, Triticum (wheat), by varying the pyrolysis time. The synthesized CDs are labeled as A 1h, A 2h, and A 3h, respectively, where “A” represents the raw material, and “1h,” “2h,” and “3h” denote the respective pyrolysis time. XRD analysis reveals the turbostratic nature of the synthesized CDs. The size and shape of synthesized samples were visualized by HRTEM images. The bandgap was calculated by Tauc's plot and was determined to be 3.66, 5.08, and 4.89 eV for A 1h, A 2h, and A 3h, respectively. FTIR measurement analyzed the functional groups present on the surface of CDs. VSM measurement confirms the ferromagnetic behavior of CDs. Synthesized CDs have been used for photocatalytic degradation of rose bengal (RB) dye under UV light irradiation. Photocatalytic degradation increases with a decrease in bandgap and the maximum degradation efficiency (90.28%) was obtained for A 1h sample.

Selenium-based nanomaterials: green and conventional synthesis methods, applications, and advances in dye degradation.

The rapidly expanding industrialization and global increase in economic activities have drawn attention to the concerning accumulation of waste. The textile industry plays a significant role in environmental pollution, especially in and water pollution. Harmful dyes used during the fabrication process are mixed with water bodies through sewage or wastewater ejected from industrial factories. These toxic dyes are not only applied in textile industries but also used in other industries like pharmaceutical companies and rubber manufacturing. Therefore, scientists have adopted alternative techniques for the degradation of organic dyes because of eliminating the drawbacks from the traditionally used techniques. Catalytic degradation of organic dyes with the help of a safe and easy nanocatalyst is one of the best alternatives. Accordingly, the use of biomaterials or waste materials offers an easy, cost-effective and eco-friendly approach for the synthesis of such nanocatalysts. Several nanocatalysts have been used for the degradation of dyes present in industrial wastewater. The well-known semi-conductor selenium has several important properties, viz., optoelectronic, photovoltaic, thermoconductivity, and anisotropy, and has drawn significant research attention for its catalytic application in dye degradation. Considering all these points, selenium nanoparticles synthesized via green techniques provide the best possible alternative catalyst for the degradation of organic dyes in industrial wastewater. The current review covers various aspects of the biosynthesis of selenium nanoparticles; their application as a catalyst for the degradation of harmful organic dyes, viz., methylene blue, methyl orange, rhodamine B, alizarin S, malachite green, sunset yellow, fuchsin, safranin T, Congo red, and bromothymol blue; and their mechanism for the degradation process. This review will also shed light on the importance of using green chemistry towards the synthesis of selenium nanoparticles and different biosynthesis procedures and explores all aspects of the interesting catalytic activity towards the dye degradation mechanism. Hence this article will be beneficial to both industrialists and acdemicians bridging the gap between industrial and academic sceintists.

Environmentally conscious synthesis of novel pyrano[2,3-d]pyrimidines via ternary deep eutectic solvents

Pyrano[2,3-d]pyrimidine and its analogues have gained considerable courtesy because of their diverse biological functions and wide-ranging applications, from pharmaceutical agents to essential natural pigments. However, synthesising pyrano[2,3-d]pyrimidine with multiple reactants is challenging and requires advanced green chemistry solutions. This study investigates the generation of thirteen new pyrano[2,3-d]pyrimidine analogues through a single-step, open-flask, multicomponent reaction (MCR) strategy involving aldehydes, phenylhydrazine, ethyl acetoacetate, and barbituric acid via deep eutectic solvents (DES). These DESs serve as environmentally friendly alternatives to traditional solvents. A ternary deep eutectic solvent (TDES) was evaluated for its catalytic solvent activity among ten different formulations. TDES-7 (5 mL) demonstrated the best performance, achieving 95 % product formation within 30 min at room temperature. Its remarkable catalytic activity and ability to produce high yields across multiple reaction cycles make it a standout choice for this application. The collaboration between MCR and TDES underscores an important blend of two significant green aspects, demonstrating their potential to achieve a green and productive sustainable synthesis method with an noble E-factor of 0.1236.

Green synthesis of Cu2S using garlic-derived sulfur: structural, morphological, optical, electrical, and photoresponse characterization with potential for thermoelectric applications.

In this study, we present an environmentally friendly and sustainable green synthesis method for Cu2S thin films using sulfur sources derived from garlic (Allium sativum L.). This novel approach facilitates room-temperature sulfurization without the need for surfactants or artificial sulfur compounds, resulting in copper sulfide films with unique nanostructured morphologies. The synthesized Cu2S films were comprehensively characterized using FESEM, RBS, PIXE, Raman spectroscopy, Hall effect measurements, and DRS to evaluate their morphological, structural, optical, electrical, and photoresponse properties. FESEM analysis revealed well-defined nanostructures with a tubular sea coral-like morphology, while RBS and PIXE confirmed the successful formation and elemental composition of Cu2S with minimal impurities. Raman spectroscopy indicated the presence of both Cu2S and Cu2O phases, suggesting partial oxidation during synthesis. The optical properties assessed via DRS demonstrated a significant reduction in the band gap energy from 2.06 eV to 1.63 eV with increasing exposure time, highlighting the tunability of the material. Hall effect measurements confirmed p-type semiconductor behavior with enhanced electrical conductivity over time, and the photoresponse study showed a strong sensitivity to visible light, making the films suitable for optoelectronic applications. Compared to conventional methods, our green synthesis offers a low-cost, scalable, and environmentally friendly alternative, with potential applications in photovoltaics and thermoelectrics. This study highlights the potential of garlic-derived sulfur for sustainable nanomaterial synthesis and paves the way for its integration into energy conversion technologies.