Green Approach Research Articles

One‐pot green approach for rapid and effective anionic dye remediation: encapsulation within alginate nanocapsules

AbstractBACKGROUNDThe encapsulation technique was applied to efficiently eliminate Congo red (CR) from aqueous solutions. During the ionotropic gelation between calcium (Ca2+) ions and alginate (AL), CR was effectively entrapped within the AL nanocapsules in a one‐step process. Suitable conditions for efficient CR removal via encapsulation were revealed by the systematic optimization of parameters including pH, time and stirring speed, etc.RESULTSAccording to the experimental observations, the stirring rate and temperature were found to have an insignificant effect on the encapsulation of CR molecules. When the pH value of the medium was 3, the highest level of encapsulation efficiency was achieved in a period of 15 min. At a preliminary CR concentration of 2000 mg L−1 and pH 3, the encapsulation efficiency was calculated at ≈98.9%, with an encapsulation capacity of 2800 mg dye g−1 AL. The zeta potential values of AL and CR/AL nanocapsules were determined to be +7.05 eV and −14.9 eV, respectively, and the results showed that the particles tended to agglomerate. TEM micrographs also showed that the nanocapsules were nanosized and agglomerated. Soil and UV degradation studies showed that the dye‐entrapped nanocapsules degraded remarkably. These results highlighted the great potential of encapsulation for dye removal in economical and practical applications.CONCLUSIONEncapsulation was confirmed to be an economical and practical technique for effectively eliminating CR from aqueous solutions. Under UV light irradiation, the dye molecules entrapped within alginate nanocapsules displayed photodegradation. © 2024 Society of Chemical Industry (SCI).

Gum karaya polymer-based biodegradable silver nanocomposite hydrogel through green approach for photocatalytic dye degradation and antimicrobial activity

The rise in industrialization and population growth has elevated water pollution to a critical environmental concern. This study introduces a novel polymer-mediated silver nanocomposite hydrogel for antibacterial activity and photocatalytic dye degradation for environmental remediation. In this study, silver nanocomposite hydrogels were developed using Karaya gum (KG), acrylamide, N-isopropyl acrylamide (NI), and 2-Bismethacryloyloxy ethyl phosphate (BMEP) as a crosslinker through a radical polymerization process. These hydrogels were utilized as templates for the eco-friendly synthesis of silver nanoparticles by employing an aqueous Canthium leaf extract as a reducing and stabilizing agent. Various analytical methods, including FTIR, UV–Vis, XPS, FESEM, EDX, XRD, AFM, and HRTEM, are characterized by the green synthesized KG-NIB-Ag nanocomposite hydrogel. Evaluation of the KG-NIB-Ag hydrogel involved examining its chemical composition, morphology, size, crystallinity, surface properties, bandgap, and chemical purity. TEM analysis validated an average crystallite size 33.2 nm. Moreover, the photocatalytic performance of the green-synthesized KG-NIB-Ag nanocomposite hydrogel was utilized to examine the degradation of Congo red dye under visible light irradiation. The findings of this study demonstrate that the degradation efficiency of CR reached approximately 73.25 % within 90 min, with a corresponding kinetic rate constant of 0.032 min−1. Furthermore, the antibacterial efficacy of the Ag nanocomposite hydrogel was evaluated against both Staphylococcus aureus and Escherichia coli. The disc diffusion method was employed to assess its antibacterial activity, and the diameter of the inhibition zones was measured. This study introduces an innovative and influential strategy for environmental remediation, emphasizing the potential of KG-NIB-Ag nanocomposite hydrogel in tackling ecological challenges associated with wastewater treatment across various industries.

Green synthesis of highly active and recyclable chromium oxide nanocatalyst for biodiesel production from novel nonedible oil seeds

AbstractThis study explores the sustainable production of biodiesel from nonedible Phyllanthus maderaspatensis seed oil (highest oil content of 35%, FFA 0.87 mg/KOH), utilizing an innovative green synthesis approach for chromium oxide nanoparticles derived from the waste fruit parts of Aubergine for the very first time in the current work. In pursuit of alternatives to fossil fuels, our research underscores the environmental and socio‐economic benefits of biofuels, particularly in reducing greenhouse gas emissions. The optimized process yielded a 92% biodiesel conversion under conditions of a 9:1 methanol‐to‐oil ratio, 0.135 wt.% catalyst concentration, and a reaction duration of 150 min at 80°C. Comprehensive analysis techniques, including XRD, FTIR, SEM, EDX, Zeta analysis, differential reflectance spectroscopy (DRS), GC–MS, and NMR (1H, 13C), were employed to characterize the synthesized nanocatalyst and biodiesel product. The biodiesel's fuel properties, such as acid value, fire point, pour point, viscosity, kinematic density, sulfur content, and cloud point, were rigorously tested, demonstrating compliance with international standards (ASTM D‐6571, EN 14214, and GB/T 20828‐2007). The use of P. maderaspatensis seed oil, an economical and environmentally friendly feedstock, in conjunction with a cost‐effective nanocatalyst, presents a viable pathway for the sustainable and scalable production of biodiesel. This study contributes to the advancement of bioproducts for a sustainable bioeconomy by demonstrating an integrated approach to bioenergy production that leverages biotechnological innovations and addresses both environmental and socio‐economic dimensions.

Human serum albumin directed formation of cadmium telluride quantum dots: Applications in biosensing, anti-bacterial activities and cell cytotoxicity measurements

Although cadmium-based quantum dots (QDs) are highly promising candidates for numerous biological applications, their intrinsic toxicity limits their pertinency in living systems. Surface functionalization of QDs with appropriate molecules could reduce the toxicity level. Herein, we have synthesized the smaller sized (1–5 nm) aqueous-compatible biogenic CdTe QDs using human serum albumin (HSA) as a surface passivating agent via a greener approach. HSA-functionalized CdTe QDs have been explored in multiple in vitro sensing and biological applications, namely, (1) sensing, (2) anti-bacterial and (3) anti-cancer properties. Using CdTe-HSA QDs as a fluorescence probe, a simple fluorometric method has been developed for highly sensitive and selective detection of blood marker bilirubin and hazardous Hg2+ ion with a limit of detection (LOD) of 3.38 and 0.53 ng/mL, respectively. CdTe-HSA QDs also acts as a sensor for standard antibiotics, tetracycline and rifampicin with LOD values of 41.34 and 114.99 ng/mL, respectively. Nano-sized biogenic CdTe-HSA QDs have shown promising anti-bacterial activities against both gram-negative, E. coli and gram-positive, E. faecalis strains confirming more effectiveness against E. faecalis strains. The treatment of human cervical cancer cell lines (HeLa cells) with the synthesized QDs reflected the proficient cytotoxic properties of QDs.

Direct Laser Writing: From Materials Synthesis and Conversion to Electronic Device Processing.

Direct Laser Writing (DLW) has been increasingly selected as a microfabrication route for efficient, cost-effective, high-resolution material synthesis and conversion. Concurrently, lasers participate in the patterning and assembly of functional geometries in several fields of application, of which electronics stand out. In this review, recent advances and strategies based on DLW for electronics microfabrication are surveyed and outlined, based on laser material growth strategies. First, the main DLW parameters influencing material synthesis and transformation mechanisms are summarized, aimed at selective, tailored writing of conductive and semiconducting materials. Additive and transformative DLW processing mechanisms are discussed, to open space to explore several categories of materials directly synthesized or transformed for electronics microfabrication. These include metallic conductors, metal oxides, transition metal chalcogenides and carbides, laser-induced graphene, and their mixtures. By accessing a wide range of material types, DLW-based electronic applications are explored, including processing components, energy harvesting and storage, sensing, and bioelectronics. The expanded capability of lasers to participate in multiple fabrication steps at different implementation levels, from material engineering to device processing, indicates their future applicability to next-generation electronics, where more accessible, green microfabrication approaches integrate lasers as comprehensive tools.

Photoelectrochemical Lithium Extraction from Waste Batteries.

The amount of global hybrid-electric and all electric vehicle has increased dramatically in just five years and reached an all-time high of over 10 million units in 2022. A good deal of waste lithium (Li)-containing batteries from dead vehicles are invaluable unconventional resources with high usage of Li. However, the recycle of Li by green approaches is extremely inefficient and rare from waste batteries, giving rise to severe environmental pollutions and huge squandering of resources. Thus, in this mini review, we briefly summarized a green and promising route-photoelectrochemical (PEC) technology for extracting the Li from the waste lithium-containing batteries. This review first focuses on the critical factors of PEC performance, including light harvesting, charge-carrier dynamics, and surface chemical reactions. Subsequently, the conventional and PEC technologies applying in the area of Li recovery processes are analyzed and discussed in depth, and the potential challenges and future perspective for rational and healthy development of PEC Li extraction are provided positively.

Green synthesis approach of nanoparticle CuFe2O4 with the assistance of chlorella green microalgae biomass extract

Green synthesis approach of nanoparticle CuFe2O4 with the assistance of chlorella green microalgae biomass extract

Development of Two Eco-Friendly and High-Throughput Microwell Spectrophotometric Methods for Analysis of an Antibacterial Drug Tulathromycin in Pharmaceutical Bulk Form.

Tulathromycin (TUL) is a triamilide antibacterial drug which has been approved for use in the European Union and the United States for the treatment and prevention of bovine respiratory diseases. The existing methods for determination of TUL in its pharmaceutical bulk form are very limited and suffer from major drawbacks. The aim of this study was the development of two innovative microwell spectrophotometric methods (MW-SPMs) for determination of TUL in its pharmaceutical bulk form. The formation of charge transfer complexes (CTCs) of TUL, as an electron donor, was investigated with 2,5-dihydroxy-3,6-dichlorocyclohexa-2,5-diene-1,4-dione (HCD) and 2,3-dichloro-5,6-dicyano-p-benzoquinone (CBQ), as π-electron acceptors. The CTCs were characterized by using UV-visible spectrophotometry and computational calculations. The reactions were employed for the development of two MW-SPMs with a one-step for the quantitative analysis of TUL. The formation of CTCs was confirmed via the formation of characteristic absorption bands with maximum absorption at 520 and 460 nm for CTCs with HCD and CBQ, respectively. The stoichiometry of both CTCs was found to be 1:1, and the values of different spectroscopic and electronic constants confirmed the stability of the CTCs. The mechanisms of the reactions were postulated. The linear range of both MW-SPMs was 10-500 µg/mL. The limits of quantitation were 13.5 and 26.4 µg/mL for methods involving reactions with HCD and CBQ, respectively. Both methods were successfully applied to the quantitation of TUL in pharmaceutical bulk form with acceptable accuracy and precision. The results of eco-friendliness/greenness assessment proved that both MW-SPMs fulfill the requirements of green analytical approaches. In addition, the one-step reactions and simultaneous handling of a large number of samples with micro-volumes in the proposed methods gave them the advantage of high throughput analysis. This study described two new MW-SPMs as valuable analytical tools for the determination of TUL.

Selective Cleavage of α-Olefins to Produce Acetylene and Hydrogen.

Acetylene production from mixed α-olefins emerges as a potentially green and energy-efficient approach with significant scientific value in the selective cleavage of C-C bonds. On the Pd(100) surface, it is experimentally revealed that C2 to C4 α-olefins undergo selective thermal cleavage to form surface acetylene and hydrogen. The high selectivity toward acetylene is attributed to the 4-fold hollow sites which are adept at severing the terminal double bonds in α-olefins to produce acetylene. A challenge arises, however, because acetylene tends to stay at the Pd(100) surface. By using the surface alloying methodology with alien Au, the surface Pd d-band center has been successfully shifted away from the Fermi level to release surface-generated acetylene from α-olefins as a gaseous product. Our study actually provides a technological strategy to economically produce acetylene and hydrogen from α-olefins.

A universal strategy towards the fabrication of ultra-high temperature ceramic matrix composites with outstanding mechanical properties and ablation resistance

Materials with both excellent mechanical properties and good ablation resistance are urgently needed for the applications of thermal protection system in extreme high temperature oxidizing environments. However, owing to the lack of efficient fabrication processes, the existing materials suffer from either insufficient mechanical properties or poor ablation resistance. Herein, we report a novel solid–liquid combination fabrication strategy that successfully achieves the efficient incorporation of ultra-high temperature ceramics into 3D continuous carbon fiber performs as well as rapid densification. The relative density of the green body approaches the cubic close packing of spherical particles. Using Cf/ZrB2–SiC as an example, the as-prepared composite exhibits outstanding mechanical properties with a flexural strength surpasses 600 MPa and an unprecedented work of fracture of 11,851 ± 838 J/m2, which is two orders of magnitude higher than that of the currently reported monolithic ultra-high temperature ceramics. Moreover, the high ZrB2 content endows the composites with excellent ablation resistance and is thus capable of maintaining long-term non-ablative conditions at 2500 °C. The strategy possesses remarkable universality and high design flexibility, providing a time-saving and cost-effective universal strategy for the on-demand design and fabrication of high-performance ceramic, carbon, metal, and polymer matrix composites.

Effective adsorption of fluorescent congo red azo dye from aqueous solution by green synthesized nanosphere ZnO/CuO composite using propolis as bee byproduct extract.

The indirect dumping of massive volumes of toxic dyes into water has seriously affected the ecosystem. Owing to the many applications of the designed nanomaterials in the manufacturing process, there is a lot of research interest in synthesizing nanomaterials using green processes. In this research, the byproduct of bee was employed to synthesize nanoparticles (NPs) of ZnO, CuO, and biosynthesized ZnO/CuO (BZC) nanocomposite via utilizing a green and simple approach. To validate the effective fabrication of BZC nanocomposite, various characterization measurements were applied. FTIR analysis identified the functional groups in charge of producing nanoparticles and nanocomposites. Moreover, the existence of ZnO and CuO XRD peaks suggests that the nanocomposites were successfully biosynthesized. The high-resolution XPS spectrum of the BZC nanocomposite's Zn2p3, Cu2p3, and O1s were observed. Our findings indicate the successful engineering of the prepared nanomaterials and BZC nanocomposite. Our findings indicate the successful engineering of the prepared nanomaterials and BZC nanocomposite. For Congo red (CR) fluorescent stain azo dye elimination in water, all adsorption parameters were examined at room temperature. Moreover, the adsorption experiments revealed the removal capacity for uptake CR dye using BZC nanocomposite (90.14mgg-1). Our results show that the BZC nanocomposite exhibited high removal capability for the adsorption of CR dye. The nanosphere adsorbent offered a simple, low-cost, and green approach for water purification and industrial wastewater control.

Indian voters’ attitude and behavior toward a political brand for producing green products: a mediation model

This study explores the attitude–behavior relationship among voters for political party brands that use a sustainable or green marketing approach. A structural equation modeling is used to analyze data collected from 1771 respondents who are registered Indian voters in this case. A positive attitude toward a political brand is compared to intentions to vote for the same brand. According to the findings, political brands create a more environmentally friendly product in the form of green actions because doing so encourages consumers to think favorably of the political brand, which results in them voting for it. As a result, authors are able to identify a positive attitude–behavior relationship for political brands among voters.

Effect of water-methanol binary solvent system in green synthesis of copper nanoparticles with tobacco leaf extract

The increasing demand for environmentally friendly nanoparticle synthesis, as a viable strategy for pollution control, has prompted an exploration of green chemistry methods. This study meticulously investigates the synthesis of copper nanoparticles utilizing tobacco leaf extract obtained through both cold and hot extraction techniques. The primary focus lies in scrutinizing the impact of various solvents employed for plant extracts and metal ion solutions on reduction dynamics and particle size. The study employs UV-Vis and phytochemical analyses to discern differences in chemical composition and efficacy, particularly between the water and methanol-water systems, despite their resemblance in UV-Vis spectra. Intriguingly, the results unveil that the choice of solvent significantly influences the particle size distribution and stability of colloidal nanoparticles. The methanol-water system, in particular, yields smaller, more uniform particles compared to other solvent systems. This research sheds light on the pivotal role of solvent selection in nanoparticle synthesis, emphasizing its profound impact on both the reduction process and the resulting particle size distribution. The findings underscore the nuanced relationship between solvent choice and the characteristics of the synthesized nanoparticles, providing valuable insights for optimizing environmentally friendly synthesis methods. Ultimately, this study contributes to the growing body of knowledge on green chemistry approaches for nanoparticle synthesis with implications for pollution control and sustainable materials production.

Polymerizable deep eutectic solvents: Convenient reactive dispersion media for the preparation of novel multi-walled carbon nanotubes-based functional materials

A new straightforward and green approach for the covalent functionalization of multi-walled carbon nanotubes (MWCNTs) was developed. This carbon nanostructure was efficiently derivatized by polymerizing proper deep eutectic monomers (DEM), a subclass of deep eutectic solvents (DES), based on a series of mono- and bis-vinyl imidazolium salts endowed with different functional groups (–OH, –NH2, –NH3+Br–) in the side chain or in the spacer. Herein, DEM systems played a triple role as convenient dispersion media for MWCNTs, efficient reactive systems, and also as structure-directing agents for the radical-initiated polymerization process onto the surface of MWCNTs. In addition, the new methodology allowed obtaining highly functionalized hybrid materials, as shown by thermogravimetric analyses, in short reaction times (<1h). Transmission electron microscopy (TEM) revealed that the polymeric network orderly develops along the surface of the nanotubes, which act as templating agent for both mono- and bis-vinyl imidazolium salts, despite the random nature of the polymerization process for the latter species. This new functionalization strategy of MWCNTs stands out for its environmentally friendly and time-saving nature leading to the formation of materials with significant potential for applications in a plethora of research fields. As a proof of their possible application, we tested these new hybrid materials as recoverable and recyclable catalysts for the conversion of CO2 into cyclic carbonates under solvent-free conditions, showing good catalytic performances, even in the absence of additional co-catalysts.

Comparison of Classical and Green RPLC Methods in the Determination of pKa Values of Some Piperazine Group Antihistamines.

In this study, protonation constant values and liquid chromatographic behaviors of hydrophobic cyclizine, chlorcyclizine, hydroxyzine, cinnarizine, cetirizine, meclizine, and buclizine in some water-organic solvent binary mixtures were examined for the first time using classical and green reverse phase liquid chromatography methods. In the isocratic study, the relationship of the retention time and mobile phase pH in water-organic solvent binary mixtures containing acetonitrile (45, 50, 55, 60, 65, v/v), methanol (60, 65, 70, 75, v/v) and ethanol (45, 50, 55, 56, 59, 60, 62, 65, v/v) were determined at 37 °C. In the study, XBridge C18 and Gemini NX C18 columns suitable for the chemical properties of basic compounds were used. The obtained liquid chromatographic data were analyzed using the linear solvation energy relationship methodology and the SOLVER program. The aqueous protonation constant values of the investigated compounds were calculated using the linear relationship between the protonation constant data calculated in studied binary mixtures and some macroscopic constant values of the solvents used. The greenness of methods developed using three different solvents was evaluated with the Analytical Greenness Metric Approach, the Green Analytical Procedures Index, and the Green Solvent Selection Tool approaches.

Nanostructured, Biodoping-Activated Fungi-Modified Wood for Enhanced Cd2+ Removal: Performances and Insight on Adsorption Mechanisms.

Nanostructured activated carbon (AC) adsorbents derived from woody biomass have garnered attention for their potential usage to remove toxic substances from the environment due to their high specific surface area, superior micro/mesoporosity, and tunable surface chemistry profile. However, chemical dopants widely used to enhance the chemical reactivity with heavy metals would pollute the environment and conflict with the vision of a cleaner and sustainable environment. Herein, we report a facile, green, and sustainable approach using fungi modification combined with alkali activation to produce AC for heavy metal removal. The decayed wood-derived AC (DAC) exhibited a high specific surface area of 2098 m2/g, and the content of O and N functional groups was 18 and 2.24%, respectively. It showed remarkable adsorption capacity toward Cd2+ of 148.7 mg/g, which was much higher than most reported Cd2+ adsorbents. Such excellent adsorption capacity was primarily based on enhanced physical adsorption (pore filling, π-π) and chemical adsorption (functional group complexation, ion exchange, and precipitation). Additionally, the DAC showed rapid kinetics and remarkable applicability in both dynamic environments and actual water samples. These results suggest that decayed wood has excellent potential for efficient use in the removal of Cd2+ from wastewater. Furthermore, these results indicate that decayed wood can be cleanly produced into high efficiency heavy metal adsorbents to realize value-added utilization of decayed wood.

Accelerated photodegradation of T-2 toxin over magnetic recyclable ZnO/CaFe2O4 nanocomposite with a p-n based Z-scheme heterojunction architecture

T-2 toxin (T-2), one of the most toxic mycotoxins, has drawn extensive attention due to its universality and persistence in food and the environment. In this study, a novel magnetic ZnO/CaFe2O4 nanocomposite with a p-n based Z-scheme heterojunction was successfully constructed by a hydrothermal method for efficient photodegradation of T-2 toxin. The optimal cubic structure of ZnO/CaFe2O4 endows it with excellent photocatalytic efficiency in removing T-2 toxin, such that near-total degradation was achieved with an exceptionally high mineralization value (64 %) after 180 min of UV radiation. This efficacy was attributed not only to the abundant reaction sites on the binary composites, but also its Z-scheme heterojunction promoting the electron-hole (e−-h+) separation and hence favors redox processes. The OH played a major role in the photodegradation, and the decomposition pathway of T-2 was proposed based on the results of UHPLC-Q-TOF-MS/MS data and density functional theory (DFT) calculations. This work provided a green approach for removing the refractory natural pollutants.

Towards greener approach: Techno-economic insights into formaldehyde bio production from a hybrid pine and mustard biomass combination

In an era marked by environmental crises and dwindling fossil resources, the need to revolutionize industrial processes for sustainability is paramount. Formaldehyde synthesis, a pivotal precursor in industries spanning polymers, resins, and textiles, stands at a critical juncture where innovation and necessity intersect. Conventional methods of formaldehyde production, despite their efficiency, remain tethered to non-renewable feedstocks and energy-intensive techniques, perpetuating ecological harm and resource constraints. This study explores eco-friendly pathways for formaldehyde production. Recent strides in bio-based chemistry enable the creation of formaldehyde from renewable biomass, reducing energy use and carbon emissions. Decentralized production with locally sourced biomass boosts supply chain resilience and community-centered sustainability. The research employs Aspen Plus® software to model a two-step process: gasification of a hybrid pine and mustard biomass blend to produce bio-methanol, followed by its oxidation into formaldehyde. Sensitivity analyses demonstrate temperature's impact on syngas composition, with higher temperatures favoring hydrogen production. The air-to-biomass ratio affects carbon dioxide content and energy content, crucial for efficient energy production. In formaldehyde synthesis, the air-to-methanol ratio significantly influences yield. Economically, formaldehyde bio- production shows promise, with an 8.50% return on investment and a 22.16-year payback period. An annual net profit of $2.41 million is projected, with a break-even point at $53.47 million in total sales revenue. This research underscores the convergence of sustainability, innovation, and economic viability in formaldehyde bio-production, offering valuable insights for environmentally friendly chemical manufacturing and the broader transition to ecological progress.

Towards More Sustainable Aqueous Zinc‐Ion Batteries

AbstractAqueous zinc‐ion batteries (AZIBs) are considered as the promising candidates for large‐scale energy storage because of their high safety, low cost and environmental benignity. The large‐scale applications of AZIBs will inevitably result in a large amount of spent AZIBs, which not only induce the waste of resources, but also pose environmental risks. Therefore, sustainable AZIBs have to be considered to minimize the risk of environmental pollution and maximize the utilization of spent compounds. Herein, this minireview focuses on the sustainability of AZIBs from material design and recycling techniques. The structure and degradation mechanism of AZIBs are discussed to guide the recycling design of the materials. Subsequently, the sustainability of component materials in AZIBs is further analysed to pre‐evaluate their recycling behaviors and mentor the selection of more sustainable component materials, including active materials in cathodes, Zn anodes, and aqueous electrolytes, respectively. According to the features of component materials, corresponding green and economic approaches are further proposed to realize the recycling of active materials in cathodes, Zn anodes and electrolytes, respectively. These advanced technologies endow the recycling of component materials with high efficiency and a closed‐loop control, ensuring that AZIBs will be the promising candidates of sustainable energy storage devices. This review will offer insight into potential future directions in the design of sustainable AZIBs.

Green synthesis of ultra-long K2Ti4O9 whiskers via cornstarch foamed calcination for large scale application

A green synthesis approach of ultra-long K2Ti4O9 whiskers suitable for large-scale application via cornstarch foamed calcination was investigated. The addition of cornstarch forms well-defined ∼ 10 μm pores and a CO2-rich atmosphere to inhibit K2CO3 decomposition. The delayed decomposition generates high amounts of K2O melt which fosters the interface growth of whiskers with lengths up to 1 mm and high aspect ratios exceeding 5000. The resulting whiskers exhibit high crystallinity, meeting strict size requirements for various applications.