Green Nanomaterials Research Articles

Enhancing the Properties of Polyvinyl Alcohol Films by Blending with Corn Stover-Derived Cellulose Nanocrystals and Beeswax.

Coating is a technique to surround a target substance with a thin layer to obtain desirable properties. Polyvinyl alcohols (PVAs) are biodegradable plastics and have shown good applicability as a coating or film material. Cellulose nanocrystals are a promising green nanomaterial that has been shown to enhance the properties of PVA after blending. However, these PVA/CNC films have concerns in a moist environment due to high hydrophilicity. To overcome this issue, the current study incorporated beeswax into PVA/CNC films and investigated the effect of CNC and beeswax on the properties of the coatings and films. Results showed that the addition of corn stover-derived CNCs to PVA films increased tensile strength (from 11 to 25 MPa) and Young's modulus (from 32 to 173 MPa) and reduced water vapor transmission rate (from 25 to 20 g h-1 m-2). Beeswax added to PVA/CNC films further improved water vapor barrier properties (from 20 to 9 g h-1 m-2) and maintained Young's modulus (from 173 to 160 MPa), though it caused a reduction in the tensile strength (from 25 to 11 MPa) of the films. This information can help to select materials for blending with PVAs by obtaining the desirable endmost properties depending on applications.

Green Nanomaterials for Clean and Sustainable Environment

Green Nanomaterials for Clean and Sustainable Environment

Recent progress on the remediation of dyes in wastewater using cellulose-based adsorbents

The increasing rise of hazardous dye (toxic and carcinogenic) in wastewater produced by multiple industries continues to become major threats to human health and environment, providing a big problem for conventional water treatment facilities to tackle this issue. Based on their appearance and physical characteristics, dyes are classified into different categories and are used in many industries. The presence of these dyes in water effluents imposes negative impacts on humans, ecosystem, and the aquatic organisms. To overcome these problems, numerous physical, chemical, and bio-based treatment methods have been researched and reported with different level of removal efficiencies based on the limitations of each approach and experimental conditions. Featuring high performance in removal efficiency, simplicity of usage, economical, and high recyclability of the absorbents have made adsorption as one of the most effective dye remediation methods. The creation of excellent nanomaterials has sped up the revolution in most industries. Green nanomaterials sourced from plant are the most promising technology as the raw materials exist in abundance in addition to the renewable resources. Nanocellulose from plant biomass exhibits excellent characteristics of renewability, biocompatibility with large surface area and high strength. In recent years, interest in utilizing nanocellulose and its derivatives as potential green approach for the removal of wastewater pollutants has emerged drastically. The present review focuses on the cellulose-based adsorptions for dye remediations, characterization aspects, parametric influence, modelling, and mechanisms.

Environment-friendly organic coordination design of Z-scheme heterojunction N-BOB/BiOIO3 for efficient LED-light-driven photocatalytic and electrochemical performance

As the climate seriously changes, ecofriendly nanomaterials have attracted tremendous interest in renewable energy as photocatalysis. Herein, we designed a new green bismuth-based Z-scheme Bi2O22+ slabs coordinate with 2-aminoterephthalic acid (N-BOB)/BiOIO3 through a simple anion exchange and postsynthetic hydrothermal reaction. FTIR, XRD, FESEM and TEM were employed to characterize the functional groups, structure, and morphologies. UV-DRS revealed the difference in band energy of the N-BOB and N-BOB/BiOIO3. Toward Rh B, TC and CIP degradation tests, 1-N-BOB/BiOIO3 manifests the best photocatalytic degradation (52.3%, 63.6% and 30.2%) efficiency. Also, 1-N-BOB/BiOIO3 possesses high durability in photocatalytic reactions and can inhibit 32.3% of bacterial growth. The results indicate that the synergistic effect between surface amine groups and Z-scheme heterojunction harvests light absorption to increase solar-to-energy (STE) efficiency, accelerate the charge separation, and increases the active sites with high photoredox potential, thus improving the photocatalytic performance. ROS scavenging tests further elucidated that photogenerated holes and hydroxyl radicals play a critical role. In addition, the surface amine groups and benzene rings can be utilized for supercapacitors and other multidisciplinary applications. 0.5 N-BOB/BiOIO3/GO impressively showed 5 times higher specific capacitance than pure GO electrode. We hope this work provides new sight into designing green nanomaterials to relieve environmental pollution and leave behind a clean future for the next generation.

Highly efficient removal of endocrine disrupting pesticides by metal ferrites loaded Guar gum based green nanomaterials

Numerous persistent and inexpensive pesticides are needed for industrial, domestic, and agricultural uses. Toxicity and bioaccumulation of pesticides have raised concerns for environment and demanding the efficient removal methods based on green nanomaterials. To substantiate this, the crystalline CdMgFe2O4@TiO2 nanocomposite incorporated in guar gum (GG) polymeric matrix (GG-CdMgFe2O4@TiO2) were employed to remove hazardous pesticides. Characterization showed that hybrid nanoparticles with polymer coating (particle size less than 100 nm) were successfully formed. PXRD revealed semi-crystalline nature and microscopic studies confirmed the wrapping of CdMgFe2O4@TiO2 with sheet like structure having size less than 100 nm. At optimum amount of GG-CdMgFe2O4@TiO2 (20 mg), Endosulfan (ES) (94%) and DDE (88%) degraded at neutral pH under sunlight. Both adsorption (GG-polymeric matrix) and photocatalytic degradation (CdMgFe2O4@TiO2) phenomenon followed for removal of target pesticides. Larger surface area (110 m2 g−1) and narrow band gap (1.9 eV) are evident for maximum eradication of pesticides by polymeric nanocomposites supports their excellent efficiency in terms of interactive and semiconducting feature. Removal phenomenon of pesticides followed Ist order kinetics and Langmuir adsorption was evident from the abrupt decrease in pesticides concentration followed by a steady reduction. Radical-scavenger analysis was used to investigate photo-catalytic reduction. LC-MS analysis proved that GG-CdMgFe2O4@TiO2 break down toxic pesticides into safer metabolites in presence of sunlight. In conclusion, polymeric GG-CdMgFe2O4@TiO2 nanocomposite may prove to be highly effective catalyst for industrial applications due to its high reusability (n = 9), higher charge separation, stability and high surface activity.

Layered Double Hydroxides for Regulating Phosphate in Water to Achieve Long-Term Nutritional Management.

Hunger and undernourishment are increasing global challenges as the world's population continuously grows. Consequently, boosting productivity must be implemented to reach the global population's food demand and avoid deforestation. The current promising agricultural practice without herbicides and pesticides is fertilizer management, particularly that of phosphorus fertilizers. Layered double hydroxides (LDHs) have recently emerged as favorable materials in phosphate removal, with practical application possibilities in nanofertilizers. This review discusses the fundamental aspects of phosphate removal/recycling mechanisms and highlights the current endeavors on the development of phosphate-selective sorbents using LDH-based materials. Specific emphasis is provided on the progress in designing LDHs as the slow release of phosphate fertilizers reveals their relevance in making agro-practices more ecologically sound. Relevant pioneering efforts have been briefly reviewed, along with a discussion of perspectives on the potential of LDHs as green nanomaterials to improve food productivity with low eco-impacts.

Nanomaterials with Plant or Animal Origin for Greener Biodelivery and Biosensor Applications: A Review

Nanomaterials are now used in almost every field of science; as conductors and electrodes in electronics, as nanodelivery systems in health screenings and drug delivery, as nanofibrils in filtering and textile industry, as nanoparticles in biosensor fabrication for toxin and pathogen detection, and in packaging materials in the food industry. Synthetic materials and plastics accumulate in the environment causing increasing health concerns for their use in food and pharmaceutical products. Therefore, researchers now try to find new greener fabrication methods for nanomaterials. In this review, some of the most recent studies were summarized and discussed where novel green nanomaterials were synthesized from plant or animal-based polymers. The focus has been given on the synthesis of 1) nanodelivery systems for bioactive and drug delivery in the form of nanoparticles, nanotubes and nanofibers, 2) nanophotonic film or nanofiber-based biosensors for food toxin and pathogen detection, and 3) functional nanocomposite films. The studies summarized here give the reader a clear understanding of the science behind creating green nanomaterial-based systems and how they are used in various applications.

Green Nanomaterials for Smart Textiles Dedicated to Environmental and Biomedical Applications.

Smart textiles recently reaped significant attention owing to their potential applications in various fields, such as environmental and biomedical monitoring. Integrating green nanomaterials into smart textiles can enhance their functionality and sustainability. This review will outline recent advancements in smart textiles incorporating green nanomaterials for environmental and biomedical applications. The article highlights green nanomaterials' synthesis, characterization, and applications in smart textile development. We discuss the challenges and limitations of using green nanomaterials in smart textiles and future perspectives for developing environmentally friendly and biocompatible smart textiles.

Green Nanocomposite Electrodes/Electrolytes for Microbial Fuel Cells—Cutting-Edge Technology

Fuel cell efficiency can be improved by using progressive electrodes and electrolytes. Green nanomaterials and green technologies have been explored for the manufacturing of high-performance electrode and electrolyte materials for fuel cells. Platinum-based electrodes have been replaced with green materials and nanocomposites using green fabrication approaches to attain environmentally friendly fuel cells. In this regard, ecological and sustainable electrode- and electrolyte-based membrane electrode assemblies have also been designed. Moreover, green nanocomposites have been applied to form the fuel cell electrolyte membranes. Among fuel cells, microbial fuel cells have gained research attention for the incorporation of green and sustainable materials. Hence, this review essentially focuses on the potential of green nanocomposites as fuel cell electrode and electrolyte materials and application of green synthesis techniques to attain these materials. The design of and interactions with nanocomposites have led to synergistic effects on the morphology, impedance, resistance, power density, current density, electrochemical features, proton conductivity, and overall efficiency. Moreover, we deliberate the future significance and challenges of the application of green nanocomposites in electrodes and electrolytes to attain efficient fuel cells.

Biphasic lignocellulose fractionation for staged production of cellulose nanofibers and reactive lignin nanospheres: A comparative study on their microstructures and effects as chitosan film reinforcing

The effective fractionation of lignocellulose and the enhancement of its components require formidable efforts. This study explored synergistic biorefinery routes for the holistic conversion of lignocellulose biomass to green nanomaterials through one-pot fractionation using recyclable p-toluenesulfonic acid (p-TsOH)/pentanol reagents. The potential of p-TsOH/pentanol pretreatment of aspen biomass under various temperatures (80–180 °C) for co-production of cellulose nanofibers (CNFs) and lignin nanospheres (LNSs) was investigated. The optimal pretreatment temperature, which minimizes cellulosic degradation and promotes the holistic conversion of biomass, was 120 °C. In addition to its highly digestible nature, the cellulose-rich residue produced high-quality CNFs with a diameter <100 nm, good crystallization, and thermostability, making it suitable for various applications. Lignin characterization, molecular dynamics simulation, and density functional theory analyses of the recovered lignin revealed well-protected β-O-4 bonds (47.3/100 Ar), uniform molecular weights (Mw, 2815 g/mol; Mn, 1704 g/mol; PDI, 1.65), < 1% sugar content, fewer condensed structures, and nanosize shapes (100–300 nm) due to the molecular interactions of p-TsOH and pentanol with lignin units. Moreover, 0.4% LNSs additions reduced the chitosan film thickness by 53% and enhanced its tensile strain and strength by 33 and 59%, respectively, as compared to the pure chitosan film. This study provides a sustainable platform for the co-production of biobased CNFs and LNSs using cutting-edge fractionation of LCB, which is a breakthrough toward industrial biorefineries.

Green nanomaterials and nanocomposites for corrosion inhibition applications

Abstract Corrosion of metals is considered a global dilemma that is attracting an increasing number of researchers in the scientific community. One of the fundamental solutions against corrosion is using corrosion inhibitors. Corrosion inhibitors are the substances added to the medium or the metal to inhibit corrosion through different mechanisms, most commonly by the formation of a protective layer on the metal surface. Organic corrosion inhibitors constitute most of the known and used corrosion inhibitors, however, due to the toxicity and cost of synthesis, green replacements are needed. Green nanomaterials corrosion inhibitors provide a green and sustainable solution for corrosion. The low toxicity, availability, and cost-effectiveness of green nanoparticles made them a growing research field. This review article highlights the synthesis, use, and application of green nanomaterials in corrosion inhibition. Moreover, the article provides insight into the different types of green nanomaterials inhibitors and their common characterization techniques.

Agro-waste to sustainable energy: A green strategy of converting agricultural waste to nano-enabled energy applications

The rising demands of the growing population have raised two significant global challenges viz. energy crisis and solid-waste management, ultimately leading to environmental deterioration. Agricultural waste (agro-waste) contributes to a large amount of globally produced solid waste, contaminating the environment, and raising human-health issues on improper management. It is essential for a circular economy to meet sustainable development goals and to design strategies to convert agro-waste into energy using nanotechnology-based processing strategies, by addressing the two significant challenges. This review illustrates the nano-strategic aspects of state-of-the-art agro-waste applications for energy harvesting and storage. It details the fundamentals related to converting agro-waste into energy resources in the form of green nanomaterials, biofuels, biogas, thermal energy, solar energy, triboelectricity, green hydrogen, and energy storage modules in supercapacitors and batteries. Besides, it highlights the challenges associated with agro-waste-to-green energy modules with their possible alternate solutions and advanced prospects. This comprehensive review will serve as a fundamental structure to guide future research on smart agro-waste management and nanotechnological innovations dedicated to its utilization for green energy applications without harming the environment. The nanomaterials assisted generation and storage of energy from agro-waste is touted to be the near-future of smart solid-waste management strategy for green and circular economy.

Biosynthesis of Zinc Oxide Nanoparticles via Leaf Extracts of Catharanthus roseus (L.) G. Don and Their Application in Improving Seed Germination Potential and Seedling Vigor of Eleusine coracana (L.) Gaertn

The ecofriendly nature of materials used in synthesis and their low cost make biosynthesized nanoparticles excellent stuff for a broad range of applications in bioscience. Green nanomaterials are progressively used in agriculture to deliver plant nutrients efficiently and effectively. The present work aimed to biosynthesize zinc oxide nanoparticles (ZnO NPs) utilizing Catharanthus roseus (L.) G. Don leaf extracts to use them as a nanopriming agent for improving seed germination and seedling growth in Eleusine coracana (L.) Gaertn (finger millet). UV-Vis spectroscopy, FTIR, FE-SEM, EDX, and TEM were used to characterize biosynthesized nanoparticles (NPs). The peaks at 362 nm characterized UV-Vis spectra of ZnO NPs. The FTIR absorption spectrum of ZnO NPs showed Zn-O bending at 547 cm−1. The size (44.5 nm) and shape (nonspherical) of ZnO NPs were revealed by TEM image analysis. XRD confirmed the hexagonal wurtzite phase of ZnO with an average particle size of 35.19. The seed germination results revealed that ZnO-nanoprimed seeds at 500 mg/L substantially improved all the seed germination parameters, viz., plumule length (23.4%), radicle length (55%), vigor index (41.94%), and dry matter production (54.6%) compared to hydropriming (control).

Green Nanomaterials for Photocatalytic Degradation of Toxic Organic Compounds.

In recent years, nanomaterials as photocatalysts have gained much popularity for the removal of organic pollutants from tainted water using photodegradation, since the available chemical, physical, and biological methods often are time consuming, involve high cost and dumping complications, sometimes posing serious threat to both human health and environmental elements. Use of nanomaterials is less expensive and does not, in general, form aggregated macromolecules. In addition, nanotechnology for waste-water treatment demolishes or alters the risky chemical wastes to harmless end products like H2O and CO2. Nanomaterials synthesized from natural resources or prepared using green synthetic routes are receiving surge of interest as our consciousness to ecological environment and safety rises. 'Green' materials of this kind might also show unique strength features and exceptional biodegradability, along with their other notable advantageous properties like minimum threat to environment, efficient recyclablity and low cost compared to synthetic nanomaterials. Such green nanomaterials can also serve as nanocatalysts to treat toxic organic pollutants in a safer way, including photodegradation to less or non-toxic products. This article reviews latest developments on the synthesis of some promising green nanomaterials aiming towards their efficient uses as photocatalysts for degradation of organic pollutants. Strategies to find new green materials as photocatalysts by modification of technologies, and development of novel methodologies for safer treatment of organic pollutants will also be discussed.

Water Purification by Green Synthesized Nanomaterials.

Water pollution is one of the important causes of human fatality in the world, particularly in underdeveloped or developing countries. Moreover, with rapid industrialization and urbanization, the problem of water pollution is posing a severe threat to health and livelihood. The pollutants found in water are of varied nature and depend on the source of the water. Several techniques have so far been adopted to purify contaminated water. All the techniques have one or the other disadvantages, limiting their applications on large scale, sustainability, and long-term usage. The advances in the field of nanoscience and technology have opened a new horizon for replacement/improvement of conventional ways with more efficient methods. Presently, green synthesized nanomaterials are being used for water purification. Plant extracts and microbes are being used to synthesize nanomaterials, which are used as catalysts, adsorbents and membranes for water purification. Nanomaterial-based techniques could create problems for the environment due to various chemicals used in their production step, thus defeating the ultimate purpose. In this regard, green nanomaterials can prove to be extremely useful both in terms of sustainability and efficiency. This review illustrates various ways of how green nanomaterials can be utilized for water remediation and summarizes the recent work done in this emerging research area.

Effect of Camellia sinensis Origin and Heat Treatment in the Iron Oxides Nanomaterials Composition and Fenton Degradation of Methyl Orange

Sustainable and environmentally friendly methods for nanomaterials synthesis have been emerging recently. The use of extracts of polyphenol-rich plants with high reducing and chelating power is advantageous because the polyphenol can protect the nanomaterial from agglomeration and deactivation. Green nanomaterials have been applied in several areas, including remediation of toxic organic pollutants from contaminated effluents. Herein, we describe the preparation of green iron oxide nanoparticles (IONPs) with extracts of the plant Camellia sinensis as black tea for dye removal application. The as-prepared IONPs were composed of amorphous FeOOH and FeII/III-polyphenol complexes. To obtain crystalline and pure iron-based nanomaterials, the amorphous precursor was annealed at 900 ºC. Samples of black tea from different regions were used to verify the reproducibility of the iron phases formed. The same iron phases were obtained for all black tea samples, α-Fe2O3 (hematite), FePO4, and Fe3PO7, but in different proportions. The materials were applied as heterogeneous-Fenton catalysts for the removal of the dye methyl orange. The amorphous as-prepared IONPs were more active than the respective annealed IONPs due to the proton release from the polyphenol into the reaction medium, setting the pH to around 3, which is the optimum pH for the Fenton system.

Green Nanomaterials: A Road Map to Safe Nanotechnology

Green Nanomaterials: A Road Map to Safe Nanotechnology

Nanocellulose-Based Polymer Composites Functionalized with New Gemini Ionic Liquids.

The manuscript discusses the application of dimeric imidazolium ionic liquids with an aliphatic linker of different lengths, constituting a new class of compounds called gemini, for the modification of renewable materials. This innovative functionalization with the use of ionic liquids made it possible to obtain polymer composite nanomaterials with renewable fillers, which will reduce the consumption of petroleum-based raw materials and also be directly related to the reduction of energy intensity. Renewable filler in the form of nanocellulose modified with ionic liquids, as well as polymer composites with such filler obtained by extrusion and injection molding techniques, were subjected to detailed characterization using techniques like: X-ray diffraction (XRD), Fourier transform spectroscopy (FTIR), dispersion studies (DLS), morphological analysis (SEM), differential scanning calorimetry (DSC), hot-stage polarized light microscopy and characterization of mechanical properties. The use of innovative dimeric ionic liquids proved to be an effective method to carry out efficient functionalization of cellulose. This provided a stable space structure between polysaccharide particles, limiting aggregate formation. It was shown that chemical modification with ionic liquids has a significant effect on the nucleation activity of cellulose fillers and the formation of the supermolecular structure of the polymer matrix, which consequently allowed to obtain polymer composites with excellent strength characteristics and increased flexibility, which will allow to increase their application potential. Innovative ionic liquids have contributed to obtaining green nanomaterials with excellent functional properties, which have not been described in the literature so far.

The role of green nanomaterials as effective adsorbents and applications in wastewater treatment

The term “nanomaterials” is used to describe a variety of subatomic particles with a size ranging from 1 to 100 nm (nm). Biological processes are used to create green nanomaterials. Natural components like microbes, trees, and organic polymers such as lipids, carbohydrates and proteins play an active role in creating green nanoparticles. Due to their small size, nanomaterials play an important role in wastewater treatment and provide opportunities for targeting higher efficiency of removing pollutants. Biopolymer-coated metal nanoparticles, Zinc oxide nanoparticles, silver nanoparticles in Aloe-Vera plant extract, magnetic nanoparticles, and silver-impregnated cyclodextrin nanocomposites are biosynthesized nanomaterials used in water pollution control. Green nanoparticles provide an alternate method of removing pollution from bodies of water. Green nanoparticles offer a cheap, simple, and environmentally acceptable wastewater treatment method.

Exploring Microbial-Based Green Nanobiotechnology for Wastewater Remediation: A Sustainable Strategy

Water scarcity due to contamination of water resources with different inorganic and organic contaminants is one of the foremost global concerns. It is due to rapid industrialization, fast urbanization, and the low efficiency of traditional wastewater treatment strategies. Conventional water treatment strategies, including chemical precipitation, membrane filtration, coagulation, ion exchange, solvent extraction, adsorption, and photolysis, are based on adopting various nanomaterials (NMs) with a high surface area, including carbon NMs, polymers, metals-based, and metal oxides. However, significant bottlenecks are toxicity, cost, secondary contamination, size and space constraints, energy efficiency, prolonged time consumption, output efficiency, and scalability. On the contrary, green NMs fabricated using microorganisms emerge as cost-effective, eco-friendly, sustainable, safe, and efficient substitutes for these traditional strategies. This review summarizes the state-of-the-art microbial-assisted green NMs and strategies including microbial cells, magnetotactic bacteria (MTB), bio-augmentation and integrated bioreactors for removing an extensive range of water contaminants addressing the challenges associated with traditional strategies. Furthermore, a comparative analysis of the efficacies of microbe-assisted green NM-based water remediation strategy with the traditional practices in light of crucial factors like reusability, regeneration, removal efficiency, and adsorption capacity has been presented. The associated challenges, their alternate solutions, and the cutting-edge prospects of microbial-assisted green nanobiotechnology with the integration of advanced tools including internet-of-nano-things, cloud computing, and artificial intelligence have been discussed. This review opens a new window to assist future research dedicated to sustainable and green nanobiotechnology-based strategies for environmental remediation applications.