Nano

Graphene in the form of film, fiber, fabrics and composites is widely investigated research area because of its remarkable physical, chemical and thermal properties. The acceptance of plant-derived products to synthesize graphene or reduced graphene oxide (RGO) has the supremacy of environmentally friendly, mild reaction condition, sustainability, cost effective and simple reaction procedure compared with conventional chemical synthesis methods. To synthesize RGO from graphene oxide (GO) in traditional chemical reduction method, highly toxic and hazardous reducing agents, capping agents, solvents are generally employed which severely affect and threaten ecological equilibrium and human well-being. In this paper, different highly facile and eco-friendly, low-cost green synthesis of RGO using aqueous plant extracts have been surveyed. The phytochemical present in plant extract, methods of preparation of the extract, detection of phytochemical present in extract, preparation of GO, methods of reduction of GO, mechanism of reduction of GO by greener way are discussed.

Nanoparticles have been considered in many fields such as medicine and industry due to their very small size and their special physicochemical properties. Biosynthesis of nanoparticles has advantages over other methods. This paper examines the bibliography of the relationship between nanotechnology and fungi from 1985 to 2021. Data were collected from three databases consisting of Web of Science, Scopus, and Dimensions. The number and type of documents were examined and then the analysis was continued using VOSviewer and Bibliometrix-package on the documents of the Scopus database. Analysis of 1203 documents from this database showed an upward trend in the publication in recent years. The term “Fungi” was also identified as the keyword index and India as the country with the most published documents. Future research is likely to be on using modern techniques in the study of nanoparticles as well as focusing on other genera of fungi.

A high-infrared (IR) emissivity is required to dissipate heat effectively from high-temperature surfaces even in a near-vacuum environment. This radiative cooling capability is essential for the emissive layer of EUV pellicles operating under high vacuum conditions with increasing EUV source powers to ensure thermomechanical stability. We compute the IR emissivity of metal films by combining the classical oscillator model and DFT calculations. Based on the calculations, we predict a positive correlation between the electrical resistivity and IR emissivity of metal films, which is consistent with a recent experiment on Ru thin films. Our findings can provide a practical indicator for achieving high IR emissivity of metallic thin films based on electrical measurements. This emissivity–resistivity correlation can provide an effective way to search a large material space, and choose and synthesize a highly emissive layer of EUV pellicles.

In this study, a group of nickel/multi-walled carbon nanotube composites has been investigated in terms of nuclear radiation shielding properties. These nickel-containing nanotubes were considered to achieve valuable results regarding radiation protection, so a detailed investigation was carried out. We have calculated mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half value layer (HVL), tenth value layer (TVL), mean free path (MFP), equivalent atomic number ($Z_{\mathrm{\text{eq}}})$, effective atomic number ($Z_{\mathrm{\text{eff}}})$, effective electron density ($N_{\mathrm{\text{eff}}})$, ratio (${\mu }_{\mathrm{\text{Compton}}}/{\mu }_{\mathrm{\text{Total}}})$ and exposure buildup factor (EBF). The obtained results are compared with the values obtained from the XMuDat program, which are in good agreement with each other. We have also analyzed them. Finally, the results obtained for nanotubes are shown in appropriate figures.

Precious metal nanoparticles, especially Ag-based nanoparticles due to their strong surface plasma effect and excellent catalytic performance, have been widely applied in environmental remediation and detection of heavy metal ions in aqueous solution. In this study, first, bimetallic Ag/Co nanoparticles (Ag/Co NPs) modified by sodium citrate were synthesized by chemical reduction method. Second, bimetallic Ag/Co NPs were used as colorimetric probe for detecting ${\text{Cr}}^{3+}$ and ${\text{Fe}}^{3+}$ in aqueous solution simultaneously for the first time. The results showed that the probe had high specificity towards ${\text{Cr}}^{3+}$ and ${\text{Fe}}^{3+}$ among the tested metal ions. When ${\text{Cr}}^{3+}$ was mixed with Ag/Co NPs, the solution quickly changed from yellow to pink, meanwhile, the UV–Vis absorption intensity declined at 400nm and a new prominent absorption band was formed at 530nm. While ${\text{Fe}}^{3+}$ was mixed with Ag/Co NPs, the solution quickly changed from yellow to nearly colorless. The linear relationship between absorbance of bimetallic Ag/Co NPs at 400nm and −log of ${\text{Cr}}^{3+}$ concentration is 1nM to 10$\mu$M, which $y=0.0084x+1.5012$ and $R^2=0.9855$. The limit of detection (LOD) for this study was 1.14nM. Similar to ${\text{Cr}}^{3+}$, the LOD for ${\text{Fe}}^{3+}$ was calculated 16.3$\mu$M. In addition, the catalytic performance of bimetallic Ag/Co NPs was evaluated by methylene blue (MB) in the presence of H₂O₂. The catalytic degradation efficiency of bimetallic Ag/Co NPs was about 4.8 times greater than monometallic Ag NPs, confirming Ag and Co NPs had obviously synergistic effect. Therefore, this result made bimetallic Ag/Co NPs had potential application in the field of environmental remediation.

Graphene is considered an excellent material for biomedical applications because of its outstanding antimicrobial performance. However, the high synthesis cost and complexity make it difficult to apply this material in numerous fields. This research focuses on synthesizing graphene nanoparticles (NPs) cost-effectively and simply. Cost-effective chemicals were used here for synthesizing graphene NPs. A simple and easy technique has been followed throughout the process. The synthesized graphene NPs were characterized by ultraviolet–visible (UV) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) and antimicrobial analyses. TEM analysis revealed the size and structure of nanosized graphene NPs. Excellent antimicrobial properties 99.99% bacterial inhibition against gram-negative bacterium E. coli have been obtained. The findings indicate the potential applications in different biomedical sectors for their improved antimicrobial properties.

To overcome the structural failure of Manganese-based Prussian blue analogue (Mn-HCF) as a cathode material of sodium ion batteries caused by Mn ion dissolution induced by Jahn–Teller effect, we coated Mn-HCF with iron-based Prussian blue (Fe-HCF) to prepare the core–shell Mn-HCF@Fe-HCF cathode material for sodium ion batteries through co-precipitation method. The research results indicate that this structure effectively blocks the direct contact between Mn-HCF and electrolyte, thereby minimizing the dissolution of ${\text{Mn}}^{3+}$ in the electrolyte and significantly improving the cycling stability and rate performance. The discharge capacity of this material at a current density of 0.1C (14mA${\text{g}}^{-1})$ is 129.7mAh${\text{g}}^{-1}$. It still has a capacity of 87.4mAh${\text{g}}^{-1}$ at a current density of 2C (280mA${\text{g}}^{-1})$, and still has a capacity retention rate of 84.3% (91mAh${\text{g}}^{-1})$ after 100 cycles at a current density of 0.5C (70mA${\text{g}}^{-1})$. Compared with the capacity retention rate of 51.5% of Mn-HCF 100 cycles before coating, the cycle stability of Mn-HCF@Fe-HCF is greatly improved.