A facile fabrication method and the boosted adsorption and photodegradation activity of CuO nanoparticles synthesized using a silk fibroin template

Green, Low-carbon Silk-based Materials in Water Treatment: Current State and Future Trends

The improper and inadequate treatment of industrial, agricultural, and household wastewater exerts substantial pressure on the existing ecosystem and poses a serious threat to the health of both humans and animals. To address these issues, different types of materials have been employed to eradicate detrimental pollutants from wastewater and facilitate the reuse of water resources. Nevertheless, owing to the challenges associated with the degradation of these traditional materials post-use and their incompatibility with the environment, natural biopolymers have garnered considerable interest. Silk protein, as a biomacromolecule, exhibits advantageous characteristics including environmental friendliness, low carbon emissions, biodegradability, sustainability, and biocompatibility. Considering recent research findings, this comprehensive review outlines the structure and properties of silk proteins and offers a detailed overview of the manufacturing techniques employed in the production of silk-based materials (SBMs) spanning different forms. Furthermore, it conducts an in-depth analysis of the state-of-the-art SBMs for water treatment purposes, encompassing adsorption, catalysis, water disinfection, desalination, and biosensing. The review highlights the potential of SBMs in addressing the challenges of wastewater treatment and provides valuable insights into prospective avenues for further research.

Pyrolyzed magnetic NiO/carbon-derived nanocomposite from a hierarchical nickel-based metal-organic framework with ultrahigh adsorption capacity

Herein, a simple one-pot solvothermal approach is used to create magnetic porous carbon nanocomposites which obtained from a nickel-based metal-organic framework (Ni-MOF) and examined for their ability to uptake methyl orange (MO) dye. Derived carbons with exceptional porosity and magnetic properties were created during the different pyrolysis temperatures of Ni-MOF (700, 800, and 900 °C) under a nitrogen atmosphere. The black powders were given the names CDM-700, CDM-800, and CDM-900 after they were obtained. A variety of analysis methods, including FESEM, EDS, XRD, FTIR, VSM, and N₂ adsorption-desorption were used to characterize as-prepared powders. Furthermore, adsorbent dosage, contact time, pH variation, and initial dye concentration effects was investigated. The maximum adsorption capacities were 307.38, 5976.35, 4992.39, and 2636.54 mg/g for Ni-MOF, CDM-700, CDM-800, and CDM-900, respectively, which show the ultrahigh capacity of the resulted nanocomposites compared to newest materials. The results showed that not only the crystallinity turned but also the specific surface area was increased about four times after paralyzing. The results showed that the maximum adsorption capacity of MO dye for CDM-700 was obtained at adsorbent dosage of 0.083 g/L, contact time of 60 min, feed pH of 3, and temperature of 45 °C. The Langmuir model has the best match and suggests the adsorption process as a single layer. According to the results of reaction kinetic studies using well-known models, the pseudo-second-order model (R² = 0.9989) displayed high agreement with the experimental data. The synthesized nanocomposite is introduced as a promising superadsorbent for eliminating dyes from contaminated water due to strong recycling performance up to the fifth cycle.

Genesis of copper oxide nanoparticles from waste printed circuit boards and evaluation of their photocatalytic activity

Discarded Printed Circuit Boards (PCBs) are one of the secondary resources of high-purity copper, and precious materials, which if disposed off inappropriately may present several environmental risks. This study focuses on the production of copper oxide nanoparticles (CuO NPs) from reclaimed copper via a facile precipitation route to obtain a value-added nanoproduct. The synthesis involved the dissolution of downsized PCBs, leaching of Cu into the solution phase and the precipitation of nanoparticles (NPs) in an alkaline medium. XRD analysis confirmed the as-synthesized NPs were monoclinic CuO of size 19.23 nm without any impurity. HRTEM analysis confirmed that the NPs were nearly round spheres with average particle size of 19.973 ± 6.036 nm. The NPs have a specific surface area of 200 m²/g and mesoporous structure with mean pore diameter of 18.051 nm. The CuO NPs photocatalyzed the degradation of Congo Red under visible light irradiation. Hence, the PCB e-waste was utilized to produce nanomaterials with added-values, decreasing environmental problems.

A comprehensive review on the metal-based green valorized nanocomposite for the remediation of emerging colored organic waste

In today's era, "green" synthesis is an emerging research trend. It has gained widespread attention owing to its dynamic behavior, reliability, simplicity, sustainability, and environment friendly approach for fabricating various nanomaterials. Green fabrication of metal/metal oxides nanomaterials, hybrid materials, and other metal-based nanocomposite can be utilized to remove toxic colored aqueous pollutants. Nanomaterials synthesized by using green approach is considered to be the significant tool to minimize unwanted or harmful by-products otherwise released from traditional synthesis methods. Various kinds of biosynthesized nanomaterials, such as animal waste and plant-based, have been successfully applied and well documented in the literature. However, their application part, especially for the cure of colored organic polluted water, has not been reported as a single review article. Therefore, the current work aims to assemble reports on using novel biosynthesized green metal-based nanomaterials to exclude harmful dyes from polluted water.

Adsorption of Safranin-O dye by copper oxide nanoparticles synthesized from Punica granatum leaf extract

The development of new technologies for water and wastewater treatment is a growing need due to the occurrence of micropollutants, such as dyes, in water resources. In this sense, green-synthesized nanoparticles are being extensively studied, due to their low cost, non-toxicity, and high efficiency in adsorption processes. Thus, the present study reports the green synthesis of copper oxide nanoparticles (CuO-NP), obtained from pomegranate (Punica granatum) leaf extract, employed for the removal of Safranin-O (SO) dye. CuO-NP was characterized by physicochemical analysis. These analyzes suggested that the redox process occurred efficiently. Also, the material presented interesting elements for the removal of cationic dyes such as negative surface charge, high specific surface area, and predominance of mesopores. The kinetic data fitted the pseudo-second-order model, reaching equilibrium in 480 min. The equilibrium study resulted in a maximum adsorption capacity of 189.54 mg g^-1 at 298 K and the experimental data best fitted the Langmuir model. The effect of pH and ionic strength did not present significant changes, which demonstrates an advantage of this adsorbent over other materials. The regeneration study allowed to verify the possibility of reuse CuO-NP, since after 4 cycles the adsorption capacity was 44% of the initial value. Considering the results found, CuO-NP has a high potential for applicability in the treatment of water contaminated by dyes.

Recent advances in functionalization of nanotextiles: A strategy to combat harmful microorganisms and emerging pathogens in the 21st century

The textile industry can benefit from nanotechnology as new properties are conferred on functionalized nanotextiles beyond what a fabric can traditionally offer. These properties include extermination of microorganisms by nanotextiles to curtail their growth and dissemination in the environment and in healthcare facilities. The emergence and thriving of multi-drug resistance (MDR) phenomenon among microbes are threats at achieving good health and well-being (goal 3) of sustainable development goals (SDG) of UN. In addition, MDR strains emerge at a higher rate than the frequency of discovery and production of potent antimicrobial drugs. Therefore, there is need for innovative approach to tackle MDR. Among recent innovations is functionalization of textiles with metal nanoparticles to kill microorganisms. This paper explores strategies in nanotextile production to combat emerging diseases in the 21st century. We discussed different nanotextiles with proven antimicrobial activities, and their applications as air filters, sportswear, personal wears, nose masks, health care and medical fabrics. This compendium highlights frontiers of applications of antimicrobial nanotextiles that can extend multidisciplinary research endeavours towards achieving good health and well-being. Until now, there exists no review on exploitation of nanotextiles to combat MDR pathogens as included in this report.

Applications of zeolite-zirconia-copper nanocomposites as a new asphaltene inhibitor for improving permeability reduction during CO2 flooding

Using nanoparticles for adsorbing asphaltene was known as an efficient method among researchers for crude oil upgrading. In this study, zeolite-zirconia-copper nanocomposites (NCs) have been synthesized and characterized with Scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and energy-dispersive X-ray (EDX). Then, CO₂-oil interfacial tension (IFT) tests, Ultraviolet–visible spectroscopy (UV–Vis) Langmuir and Freundlich isotherm models, asphaltene precipitation tests at static phase, and dynamic CO₂ flooding tests were performed in the presence of NCs and the results were compared with zeolite nanoparticles. Based on the characterization results, zirconia-copper particles were distributed at the surface of zeolite with total dimensions less than 30 nm, and the specific surface areas of the NCs (327.82 m²/g) was less than the pure zeolite (369.48 m²/g). It was seen that NCs had a greater asphaltene adsorption capacity and the application of decreasing asphaltene precipitation was higher in comparison to the zeolite nanoparticles. Accordingly, NCs were selected for performing dynamic CO₂ tests and investigation of the permeability and porosity reduction parameters at obtained static condition. After adding NCs at the dynamic phase, asphaltene depositions that occured after CO₂ injection was decreased and permeability/porosity reduction parameters were improved.

Silk Polymers and Nanoparticles: A Powerful Combination for the Design of Versatile Biomaterials

Silk fibroin (SF) is a natural protein largely used in the textile industry but also in biomedicine, catalysis, and other materials applications. SF is biocompatible, biodegradable, and possesses high tensile strength. Moreover, it is a versatile compound that can be formed into different materials at the macro, micro- and nano-scales, such as nanofibers, nanoparticles, hydrogels, microspheres, and other formats. Silk can be further integrated into emerging and promising additive manufacturing techniques like bioprinting, stereolithography or digital light processing 3D printing. As such, the development of methodologies for the functionalization of silk materials provide added value. Inorganic nanoparticles (INPs) have interesting and unexpected properties differing from bulk materials. These properties include better catalysis efficiency (better surface/volume ratio and consequently decreased quantify of catalyst), antibacterial activity, fluorescence properties, and UV-radiation protection or superparamagnetic behavior depending on the metal used. Given the promising results and performance of INPs, their use in many different procedures has been growing. Therefore, combining the useful properties of silk fibroin materials with those from INPs is increasingly relevant in many applications. Two main methodologies have been used in the literature to form silk-based bionanocomposites: in situ synthesis of INPs in silk materials, or the addition of preformed INPs to silk materials. This work presents an overview of current silk nanocomposites developed by these two main methodologies. An evaluation of overall INP characteristics and their distribution within the material is presented for each approach. Finally, an outlook is provided about the potential applications of these resultant nanocomposite materials.

Silk Fibroin-Based Materials for Catalyst Immobilization

Silk fibroin is a widely and commercially available natural protein derived from silkworm cocoons. Thanks to its unique amino acid composition and structure, which lead to localized nanoscale pockets with limited but sufficient hydration for protein interaction and stabilization, silk fibroin has been studied in the field of enzyme immobilization. Results of these studies have demonstrated that silk fibroin offers an important platform for covalent and noncovalent immobilization of enzymes through serving as a stabilization matrix/support with high retention of the biological activity of the enzymes of interest. In the hope of providing suggestions for potential future research directions, this review has been written to briefly introduce and summarize key advances in silk fibroin-based materials for immobilization of both enzymes/biocatalysts (including alkaline phosphatase, β-glucosidase, glucose oxidase, lipase, urease, uricase, horseradish peroxidase, catalase, xanthine oxidase, tyrosinase, acetylcholinesterase, neutral protease, α-chymotrypsin, amylase, organophosphorus hydrolase, β-galactosidase, carbonic anhydrase, laccase, zymolyase, phenylalanine ammonia-lyase, thymidine kinase, and several others) and non-enzymatic catalysts (such as Au, Pd, Fe, α-Fe2O3, Fe3O4, TiO2, Pt, ZnO, CuO, Cu2O, Mn3O4, and MnO2).

Development of CuO particles onto bacterial cellulose sheets by forced hydrolysis: A synergistic approach for generating sheets with photocatalytic and antibiofouling properties

CuO was successfully prepared on bacterial cellulose paper as a nanocomposite using the forced hydrolysis technique. The composite paper presented outstanding photocatalytic and antibacterial properties. The effect of pH from 7 to 11 on CuO formation on bacterial cellulose was tested. The structural properties of the composite were investigated by Fourier transform infrared spectroscopy and X-ray diffraction. Thermogravimetric analysis showed that the composite has a thermal resistance of up to 200 °C. Scanning electron microscopy showed that bacterial cellulose existed as a network and that CuO particles filled the spaces in the network. Energy-dispersive and mapping analysis also showed the optimal uniformity and distribution. The composite paper will act as the prototype for both photocatalyst and antibacterial properties for paper-based technology.