Green synthesis and characterization of Fe doped ZnO nanoparticles and their interaction with bovine serum albumin

Herein we report an eco-friendly and cost efficient synthesis of Fe doped ZnO (TPFZO) nanoparticles using the extract of Thespesia polpulanea flowers as a stabilizing agent. The synthesized NPs have been characterized by XRD, FT-IR, UV-DRS, SEM, EDAX and TEM studies. The synthesized NPs were found to have the crystallite size in the range of 30–60 ​nm. The calculated band gap energies for ZO and TPFZO nanoparticles were 3.00 ​eV and 1.97 ​eV respectively. The size distribution of the ZO and TPFZO obtained from TEM were observed to be lying in the range 50–120 ​nm and 4–22 ​nm respectively. The interaction of TPFZO NPs with bovine serum albumin (BSA) has been studied using fluorescence and absorption titration methods. The results indicated that the nanoparticles quenched the BSA fluorescence at 340 ​nm via static quenching mode having a bimolecular quenching rate constant value of 6.21 ​× ​10¹³ Lmol⁻¹s⁻¹.     

Extraction of acephate pesticide in environmental and agricultural samples by spectrophotometric method

In the present study, we have synthesis the azo dye for the reaction of p-amino antipyrine with HCl in NaNO₂ solution a 1:1 ​M ratio that was kept -5°C for 1–2 ​h, as result the absorption spectra observed at λ_max ​= ​460 ​nm. Beer’s law is obeyed over the awareness variety of 1 ​μg–100 ​μg ​mL^-1. The standard deviation and relative well-known deviation are 0.007 and 1.38%. The molar absorptivity and Sandell's sensitivity had been located to be 0.98 ​× ​10⁵ ​L ​mol^-1 ​cm^-1 and 0.99 ​× ​10^-3 ​μg ​cm^-2, respectively. Spectroscopy method used for the detection of Acephate pesticides on vegetable, fruit, soil, and water samples. FTIR method was used to consider and achieve structural information about the presented intermolecular interactions for vegetable samples. The eco-friendliness of the developed methods was assessed using the spectroscopy analytical tool on vegetables, fruit, soil, and water samples.     

Facile synthesis of superparamagnetic manganese ferrite nanoparticles as a novel T2 MRI contrast agent

With co-precipitation method we successfully synthesized an aqueous dispersible, superparamagnetic manganese ferrite nanoparticles at relatively low temperature (190 ​°C). This material shows potential application as T₂ MRI contrast agent. Cost-effective and less toxic manganese (II) chloride (MnCl₂·4H₂O) and iron (III) chloride hexahydrate (FeCl₃·6H₂O) were used as precursors and 2-[2-(2-Hydroxyethoxy)ethoxy] ethanol (TEG) were utilized as solvent which served as stabilizer and provided a reduction system. The mean diameter of these nanoparticles is about 7 ​nm. Its saturation magnetization (Ms) and relaxivity value (r₂) are as high as 46 emu/g and 593.9 ​mM⁻¹s⁻¹ respectively. In vitro cell study demonstrated pancreatic cancer cells could keep viable when the manganese ferrite nanoparticles concentration reached up to 50 ​μg/mL.     

Antibacterial studies of bio-functionalized carbon decorated silver nanoparticles (AgNPs)

In the present report, Lemon juice (bio-extract) extract was efficaciously used for the synthesis of bio-functionalized silver nanoparticles (Ag-1, Ag-2 & Ag-3 NPs) and decorated with carbon material obtained from mustard oil. The morphology, size, crystal structure, formation and interaction were studied by means of innumerable analytical methods including scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy. The XRD results approve the formation of AgNPs with face-centered cubic (fcc) lattice. The XRD results also exhibit some unassigned peaks which might be due to the presence of bio-organic materials on the surface of AgNPs. The bands observed from the IR spectra showing the involvement of biomolecules onto the surface of silver nanoparticles. Mostly citric acid plays a major role in bio-reduction, capping agent, and stabilization of silver ions. We attained maximal inhibition zone (2.10 ​± ​0.05 and 2.03 ​± ​0.027) counter to gram-negative bacteria K. pneumoniae and P. bacilli with Ag-3 respectively, but lowest inhibition zone (1.27 ​± ​0.22) contrary to S. aureus as a gram-positive bacteria with Ag-2.     

Magnetically separable tea leaf mediated nickel oxide nanoparticles for excellent photocatalytic activity

Synthesis of nanoparticles having low chemical toxicity has been interest of researchers for decades. Utilization of plant phytochemicals as reducing agent is now a globally recognized alternative technique for environmental friendly and low-cost production of nanoparticles. This work reports a facile green synthesis protocol of Nickel Oxide nanoparticles (NiO NPs) using fresh tea leaf extract. The synthesized nanoparticles have been characterized through various analytical techniques like Powder XRD (P-XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The XRD results reveal the formation of crystalline nickel oxide nanoparticles. FTIR spectrum displays the existence of different polyphenolic groups over NiO NPs surface. TEM and SEM images indicate the formation of slightly agglomerated spherical nanoparticles with particle size 3–5 ​nm. The nanoparticles were used towards the photocatalytic degradation of both cationic, anionic dyes and their mixtures under optimum conditions in the presence of UV light irradiation. More than 95% degradation was observed for all the dye solutions with 30 ​mg ​L^-1 catalytic dose. Moreover, the degradation efficiency of the nanoparticle was studied by altering various parameters like pH, initial dye concentration and amount of catalytic dose. Pseudo first order kinetic model was employed in all the reactions. A detailed mechanism and kinetics of the all the reactions were studied. Interestingly, the catalyst showed excellent recyclability up-to 4th cycles with very low catalytic activity loss.     

Ag doped α-Fe2O3 nanoparticles: Synthesis,characterization and application as heterogeneous photocatalyst for removal of organic dye from aqueous media without any oxidizing agents

α-Fe₂O₃ and Ag doped α-Fe₂O₃ nanostructures were synthesized by wet chemical reflux method. XRD analysis established formation of α-Fe₂O₃ phase for un-doped nanostructures while for Ag-α-Fe₂O₃ the diffraction peaks shift slightly towards higher angle. FESEM suggests the development of fine nanostructures with particle size order of 40–70 ​nm for pristine α-Fe₂O₃ NPs, whereas comparatively larger size NPs with order of 60–110 ​nm for Ag-α-Fe₂O₃. The NPs were used as photocatalysts for degradation of eosin yellow and malachite green dyes in aqueous medium under visible light irradiation. Ag-α-Fe₂O₃ NPs efficiently decolourize about 98% dye molecules within 90 ​min.     

Facile synthesis and characterization of monocrystalline cubic ZrO2 nanoparticles

Crystalline ZrO₂ nanoparticles were prepared from zirconium isopropoxide by slow hydrolysis and subsequent hydrothermal treatment of solutions containing various amounts of sodium hydroxide at 180 °C. Whereas moderately basic solutions lead to the formation of nanoparticles of monoclinic ZrO₂ with plate-like morphology, and nanoparticles of the cubic ZrO₂ high-temperature polymorph with diameters of approx. 5 nm were obtained from strongly basic solutions. The morphology, structure and properties of as-synthesized nanoparticles were characterized using HRTEM, XRD, Raman spectroscopy, UV–vis, PL spectroscopy and BET measurements. The formation of both, the monoclinic and the cubic polymorph, was confirmed by electron microscopy and Raman spectroscopy. The crystallinity and morphology of the resulting ZrO₂ nanoparticles can be adjusted by the choice of the reaction conditions. The cubic ZrO₂ nanoparticles have a high surface area (300 m²/g) and exhibit a strong photoluminescence in the UV region.     

Surface facets dependent oxygen evolution reaction of single Cu2O nanoparticles

Understanding and establishing the structure-activity relation of nanoparticles is a prerequisite for rational design of high-performance electrocatalysts. Cu₂O nanoparticles enclosed with different crystal facets, namely, o-Cu₂O NPs with {111} facets, c-Cu₂O NPs with {100} facets are prepared and their electrocatalytic properties for oxygen evolution reaction (OER) in alkaline condition are evaluated at single nanoparticle level with a combination of scanning electrochemical cell microscopy and scanning electron microscopy. It is found that the o-Cu₂O NPs have significantly superior OER electrocatalytic activity compared to c-Cu₂O, which is almost inert. The estimated turnover frequency (TOF) at 1.97 V vs. RHE on {111} facet increases from 4 s^?1 to 115 s^?1 with the octahedron edge length decreasing from 1.3 µm to 100 nm. Deposition of carbon on c-Cu₂O surface barely promotes the activity, suggesting the inherent poor electric conductivity within the nanocrystal is most likely the reason for low activity. This work provides direct probing to single transition metal oxide crystals with dramatically different activity.     

Gamma-ray induced thermoluminescence emission of green synthesized zinc oxide nanophosphors

The thermoluminescence (Thermally stimulated luminescence) technique has been applied in the field of radiation dosimetry and was found to be highly successful in dating ancient pottery samples. It is also used in the study of biological and biochemical systems. The present study reports the gamma-ray exposed thermoluminescence (TL) emission of ZnO nanophosphors. ZnO nanoparticles were prepared via phyto-mediated green routes according to our previous works. Different analytical techniques such as XRD, FESEM, HRTEM, XPS, EDS, FTIR, and UV-DRS were employed to characterize the samples. The ZnO nanoparticles possess hexagonal wurtzite crystal structure of with 29–71 ​nm particle dimension. TL emission of the samples was recorded with different gamma dosages10-50 Gy at a constant heating rate of 2^oCs^-1. A broad single glow curve above 300 ​°C was exhibited by the samples and good linearity was reserved in integrated TL profiles. The TL emission follows first-order kinetics and the activation energies of the traps located in the samples were determined.     

Synthesis and characterization of CuO nanoparticles utilizing waste fish scale and exploitation of XRD peak profile analysis for approximating the structural parameters

In this research, we strived to utilize waste fish scale (labeo rohita) for synthesizing CuO nano-particles (CuO NPs), which gained much attention due to its distinctive properties and versatile applications. Upon the heat treatment, the collagen content of the fish scale got transformed into gelatin which in turn converted the precursor material into CuO NPs. The X-Ray diffraction (XRD) analysis confirmed the formation of CuO NPs and revealed the structure to be of monoclinic lattice. The structural parameters i.e. crystallite size, lattice parameters, microstrain, dislocation density was evaluated for the synthesized CuO NPs using the XRD data. Scherrer’s Method (SM), Scherrer Equation Average Method (SEAM), Linear Straight Line Method (LSLM), Straight Line Passing the Origin Method (SLPOM), Monshi Scherrer Method (MSM), Williamson-Hall Method (WHM), Size-Strain Plot Method (SSPM), Halder-Wagner Method (HWM) was exploited for the estimation of crystallite size. According to the calculations, the crystallite size was found to be 87 nm, 41 nm, 1980 nm, 62 nm, 66 nm, 28 nm, 13 nm, 13 nm respectively and the dislocation density was found to be 1.32 × 10^-4, 5.95 × 10^-4, 0.002 × 10^-4, 2.60 × 10^-4, 2.29 × 10^-4, 12.75 × 10^-4, 59.17 × 10^-4 and 59.17 × 10^-4 respectively. UV–Vis absorption analysis also confirmed the formation of CuO NPs based on the absorption peak at 262 nm (λ_max) and Tauc Plot method was used to calculate the optical band gap which was 3.84 eV. Functional group, especially the Cu-O bonding was confirmed by the Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) data. Field Emission Scanning Electron Microscopy (FESEM) showed three different shapes of CuO NPs which was also confirmed by Transmission Electron Microscopy (TEM). Particle size was determined based on FESEM and TEM image using imageJ software and also by the Dynamic Light Scattering (DLS) technique. Thermal analysis showed a four stage weight loss in case of Thermogravimetric (TGA) analysis and three conversion steps was observed in Differential Scanning Calorimetric (DSC) analysis. Such synthesis pathway is evidently green and facile for synthesizing CuO NPs with potentiality of various applications and also utilization of waste fish scale is a perquisite.     

Synthesis of Zinc Oxide Nanoparticles Using Rubus fairholmianus Root Extract and Their Activity against Pathogenic Bacteria

Recently, the biosynthesis of zinc oxide nanoparticles (ZnO NPs) from crude extracts and phytochemicals has attracted much attention. Green synthesis of NPs is cost-effective, eco-friendly, and is a promising alternative for chemical synthesis. This study involves ZnO NPs synthesis using Rubus fairholmianus root extract (RE) as an efficient reducing agent. The UV spectrum of RE-ZnO NPs exhibited a peak at 357 nm due to intrinsic bandgap absorption and an XRD pattern that matches the ZnO crystal structure (JCPDS card no: 36-1451). The average particle size calculated from the Debye–Scherrer equation is 11.34 nm. SEM analysis showed that the RE-ZnO NPs spherical in shape with clusters (1–100 nm). The antibacterial activity of the NPs was tested against Staphylococcus aureus using agar well diffusion, minimum inhibitory concentration, and bacterial growth assay. The R. fairholmianus phytochemicals facilitate the synthesis of stable ZnO NPs and showed antibacterial activity.     

Regulation of the PI3K/AKT/mTOR signaling pathway with synthesized bismuth oxide nanoparticles from Ginger (Zingiber officinale) extract: Mitigating the proliferation of colorectal cancer cells

In order to overcome the limitations of conventional therapeutic systems in the treatment of cancer, nanoparticles (NPs) have been rapidly produced and developed as a separate treatment method for control of cancer. Synthesis of nanoparticles using plant-based materials (green synthesis), due to the easy and cost-effective synthesis, production of non-toxic, sustainable and environmentally friendly products, can be considered the most appropriate method for preparation of NPs. In this study, after synthesis of Bi₂O₃ NPs using Ginger (Zingiber officinale) root (rhizome) extract, the synthesized NPs were characterized and their potential application as selective anticancer agents against HCT116 colorectal cancer cells was evaluated through regulation of PI3K/AKT/mTOR signaling pathway, whereas the human kidney (HK-2) cells were used as normal cells. FTIR analysis showed a band at 673 cm^?1 attributed to Bi-O vibration with a fingerprint region at 1291 cm^?1 demonstrating the attachment of the organic molecules to the synthesized Bi₂O₃ NPs. UV–visible study showed a λ_max of around 268 nm, whereas XRD analysis showed eight clear peaks, demonetizing the crystalline phase of synthesized Bi₂O₃ NPs. TEM analysis showed that spherical-shaped Bi₂O₃ NPs have a size range of 20–50 nm with a man size of around 35 nm. Finally, DLS analysis determined that Bi₂O₃ NPs have a hydrodynamic size of about 71.19 nm (PDI of 0.179) and a zeta potential value of ?44.39 mV, revealing the good colloidal stability of NPs. Cellular assays (MTT, LDH, flow cytometry, and RT-qPCR) showed that synthesized Bi₂O₃ NPs selectively induced anticancer effects against HCT116 colorectal cancer cells through membrane leakage, generation of ROS, induction of apoptosis via dysregulation of Bax, Bcl-2 and caspase-3 at mRNA level mediated via regulation of PI3K/AKT/mTOR signaling pathway. In conclusion, it may be suggested that the presence study could provide useful information for the potential anticancer effects mediated by synthesized Bi₂O₃ NPs in vitro, although further studies, including in vivo studies and clinical trials, are needed to support our findings.     

CZTS nanoparticles by one-pot sonochemical route – Effect of power density,pH and bath temperature

One-pot synthesis of nanosized CZTS particles using ultrasound employing citric acid as the complexing agent has been studied. The CZTS nanoparticles synthesis at different bath temperatures, pH and power densities was attempted. The power density used for the reaction did not alter the crystallinity and morphology of the synthesized particles. However, the chemical composition and the bandgap of the particles showed significant variation with the applied power density. Apart from affecting the composition, bandgap and electrical characteristics, the bath temperature considerably affected the crystallinity of the CZTS nanoparticles. Based on the conditions of synthesis, the particle size ranged between 25 ​nm and 40 ​nm. Depending on the process conditions, the bandgap of the particles varied between 1.4 ​eV and 2.9 ​eV. The samples synthesized under a power density of 46 ​W ​L⁻¹ and 40 ​°C bath temperature with reactant pH of 3.5 showed composition closer to the required stoichiometry.     

Lime peel extract induced NiFe2O4 NPs: Synthesis to applications and oxidative stress mechanism for anticancer,antibiotic activity

Nanobiotechnology, joined with green science, has incredible potential for the advancement of novel and important products that benefit human health, climate, and industries. Green chemistry of materials from synthesis to diverse biomedical applications is a talk of town in today’s sustainable ideal world. Green synthesized nickel ferrites nanoparticles via biogenic lime peel extract (LPE) are investigated with precision and complete trail has been reported as multiple efficacies. The fcc crystal structure with the crystallite size (31 nm) were accessed by the XRD, magnetic properties using VSM, and FTIR for the functional group analysis of NiFe₂O₄ nanoparticles mediated by Lime peel extract (NiFe₂O₄@LPE NPs). From TEM and SEM analysis the average diameter of the NPs was observed in the range of 31–35 nm. In 3D view, the surface morphology was analyzed by the AFM. NiFe₂O₄@LPE NPs were used to assess cytotoxicity and cellular morphological alterations in In Vitro cervical cancerous cells (HeLa). Nanosized NiFe₂O₄@LPE accompanied the considerable NPs topology induced dose dependent MMP in HeLa cells unlike the previous interpretation of controlled metabolism anticancer activity for HeLa cancerous cells. Therefore, it is referred by oxidative stress and reduction phenomena for anticancer effects and inactivation of carcinogen. Moreover, Antioxidant DPPH radical scavenging method and antibacterial Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus activity were observed in the synthesized nickel ferrites NPs.     

Multifunctional ZrO2 nanoparticles and ZrO2-SiO2 nanorods for improved MALDI-MS analysis of cyclodextrins, peptides, and phosphoproteins

Multifunctional ZrO₂ nanoparticles (NPs) and ZrO₂-SiO₂ nanorods (NRs) have been successfully applied as the matrices for cyclodextrins and as affinity probes for enrichment of peptides (leucine-enkephalin, methionine-enkephalin and thiopeptide), phosphopeptides (from tryptic digestion products of β-casein) and phosphoproteins from complex samples (urine and milk) in atmospheric pressure matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) and MALDI time-of-flight (TOF) MS. The results show that the ZrO₂ NPs and ZrO₂-SiO₂ NRs can interact with target molecules (cyclodextrins, peptides, and proteins), and the signal intensities of the analytes were significantly improved in MALDI-MS. The maximum signal intensities of the peptides were obtained at pH 4.5 using ZrO₂ NPs and ZrO₂-SiO₂ NRs as affinity probes. The limits of detection of the peptides were found to be 75-105 fmol for atmospheric pressure MALDI-MS and those of the cyclodextrins and β-casein were found to be 7.5-20 and 115-125 fmol, respectively, for MALDI-TOF-MS. In addition, these nanomaterials can be applied as the matrices for the analysis of cyclodextrins in urine samples by MALDI-TOF-MS. ZrO₂ NPs and ZrO₂-SiO₂ NRs efficiently served as electrostatic probes for peptide mixtures and milk proteins because 2–11 times signal enhancement can be achieved compared with use of conventional organic matrices. Moreover, we have successfully demonstrated that the ZrO₂ NPs can be effectively applied for enrichment of phosphopeptides from tryptic digestion of β-casein. Comparing ZrO₂ NPs with ZrO₂-SiO₂ NRs, we found that ZrO₂ NPs exhibited better affinity towards phosphopeptides than ZrO₂-SiO₂ NRs. Furthermore, the ZrO₂ and ZrO₂-SiO₂ nanomaterials could be used to concentrate trace amounts of peptides/proteins from aqueous solutions without tedious washing procedures. This approach is a simple, straightforward, separation-and washing-free approach for MALDI-MS analysis of cyclodextrins, peptides, proteins, and tryptic digestion products of phosphoproteins.      

Ag nanoparticles immobilized on guanidine modified-KIT-5 mesoporous nanostructure: Evaluation of its catalytic activity for synthesis of propargylamines and investigation of its antioxidant and anti-lung cancer effects

The current study involves the novel synthesis of Ag nanoparticles (Ag NPs) decorated biguanidine modified mesoporous silica KIT-5 following post-functionalization approach (KIT-5-bigua-Ag). The tiny Ag NPs were being stabilized over the in situ prepared biguanidine ligand. The high surface area material was characterized using advanced analytical methods like Fourier Transformed infrared (FT-IR) spectroscopy, N₂-adsorption–desorption isotherm, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction study (XRD). The material was having large pore cage like structure with pore diameter of 8–10 nm. TEM study displayed the particles size of deposited Ag NPs were 10–15 nm. The KIT-5-bigua-Ag nanocomposite had a significantly high surface area of 318 m²/g (BET analysis). Towards the chemical applications of the material, we headed the three-component reaction of aldehydes, amines and alkynes (A³ coupling) with good to excellent yields (70–98%) of diverse Propargylamines. The catalyst was easily isolable and reused in 8 cycles without any leaching and considerable change in its reactivity. In addition, the KIT-5-bigua-Ag nanocomposite was engaged in biological assays like study of anti-oxidant properties by DPPH mediated free radical scavenging test using BHT as a reference molecule. Thereafter, on having a significant IC50 value in radical scavenging assay, we extended the bio-application of the desired nanocomposite in anticancer study of A549 cell of human lung in-vitro conditions. In the cytotoxicity and anti-human lung studies, the nanocomposite was treated to lung cancer A549 cell line following MTT assay. The cell viability of malignant lung cell line reduced dose-dependently in the presence of KIT-5-biguanidine-Ag nanocomposite. IC50 values of the nanocomposite were observed to be 915.22 μg/mL against A549 cell line. So, these results suggest that KIT-5-bigua-Ag as a novel chemotherapeutic nanocomposite have a suitable anticancer activity against lung cell lines.     

Biomimetic synthesis of CuInS2 nanoparticles: Characterization,cytotoxicity, and application in quantum dots sensitized solar cells

CuInS₂ (CIS) nanoparticles have unique chemical, toxicological and optoelectronic properties that favor their technological applications. In the present work we report a novel one step biomimetic method for the aqueous synthesis of CIS nanoparticles, that is also low cost and environmentally friendly. This biomimetic method uses only CuSO₄ and InCl₃ as precursor salts, and the biological molecule glutathione as sulfur donor and stabilizer of the nanoparticles (NPs). The reaction is performed at low temperatures, under aerobic conditions and atmospheric pressure. CIS nanoparticles produced by our biomimetic method exhibit fluorescence emission between 650 and 700 nm when excited at 500 nm. A size between 10 and 15 nm was determined by Dynamic light scattering (DLS) and corroborated by electron transmission microscopy. X-ray diffraction analysis (XRD) confirmed the crystalline structure of the CIS NPs produced. Energy Dispersive X-Ray Spectroscopy (EDX) analyses revealed the presence of Cu, In, and S in a 0.6: 1.4: 2 ratio, which has been reported for other CIS NPs in literature. No cytotoxicity of CIS NPs was observed in human OKT6/TERT2 cells and bacteria. Besides, the potential application of biomimetic CIS NPs as photosensitizers in quantum dots sensitized solar cells (QDSSCs) was confirmed. The biocompatibility, spectroscopic properties, and energy harvesting performance in solar cells of the CIS NPs produced by our biomimetic method make them suitable for their use in different biotechnological applications.     

Sterculia foetida fruit shell based activated carbon for the effective removal of industrial effluents

In this work, Sterculia foetida fruit shells were used for the preparation of activated carbon and utilized for the removal of industrial effluent methylene blue is described. The carbon materials were prepared by washing the shells with water, dried in sunlight and subjected to heating at 700 ​°C in a muffle furnace to get the carbon material. This is divided into three portions, one is used as pristine and two portions were subjected to physical activation using steam and chemical activation using K₂CO₃. The impurities were removed by treatment with NaOH (0.1 ​M) and subsequently with HCl (0.1 M). Turbostatic structure was determined by XRD and the specific surface area was determined using BET showed 4, 1017 and 596 ​m²/g as the surface areas. Using these activated carbon materials, we have achieved 93% removal of methylene blue, found in industrial effluents.     

Nitrate removal from aqueous solution using watermelon rind derived biochar-supported ZrO2 nanomaterial: Synthesis,characterization, and mechanism

Recently, biochar has attracted tremendous research interest for environmental applications. In this study, biochar-derived watermelon rind (WM) was produced via optimal pyrolysis at 500 °C for 2 h, and then improved the adsorption capacity by Zirconium oxide nanoparticles (ZrO₂ NPs). The WM@ZrO₂ was characterized using X-ray diffraction (XRD), Scanning electron microscopic - Energy-dispersive X-ray spectroscopy (SEM-EDS), and Fourier transform infrared (FTIR). The adsorptive capacities of synthesized ZrO₂ NPs were investigated for nitrate as a function of pH, adsorbent dosage, contact time, initial adsorbate concentration, and pyrolysis temperature in the batch experiment. The results showed that a Langmuir isotherm and a pseudo-second-order kinetics model were the best-fit for experimental nitrate data in its non-linear form as correlation coefficients (R²) were 0.985 and 0.998, respectively. The maximum adsorption capacity for the Langmuir isotherm model was 15.196 mg g^?1. The proposed mechanism, including electrostatic attraction and ligand exchange, played a dominant role in nitrate adsorption. After testing with the real domestic wastewater, the removal of nitrate for WM@ZrO₂ was achieved at 78 %, which was equivalent to the adsorption capacity of 8.1 mg g^?1 of adsorbent. Overall, the WM@ZrO₂ is proposed as a promising, effective, and environmentally friendly adsorbent in removing nitrate from an aqueous solution.     

Optical and electrical conducting properties of Polyaniline/Tin oxide nanocomposite

Polyaniline(PANI)/Tin oxide (SnO₂) hybrid nanocomposite with a diameter 20–30 nm was prepared by co-precipitation process of SnO₂ through in situ chemical polymerization of aniline using ammonium persulphate as an oxidizing agent. The resulting nanocomposite material was characterized by different techniques, such as X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier Transform Infrared spectroscopy (FT-IR) and Ultraviolet–Visible spectroscopy (UV–Vis), which offered the information about the chemical structure of polymer, whereas electron microscopy images provided information regarding the morphology of the nanocomposite materials and the distribution of the metal particles in the nanocomposite material. SEM observation showed that the prepared SnO₂ nanoparticles were uniformly dispersed and highly stabilized throughout the macromolecular chain that formed a uniform metal-polymer nanocomposite material. UV–Vis absorption spectra of PANI/SnO₂ nanocomposites were studied to explore the optical behavior after doping of nanoparticles into PANI matrix. The incorporation of SnO₂ nanoparticles gives rise to the red shift of π–π¹ transition of polyaniline. Thermal stability of PANI and PANI/SnO₂ nanocomposite was investigated by thermogravimetric analysis (TGA). PANI/SnO₂ nanocomposite observed maximum conductivity (6.4 × 10^?3 scm^?1) was found 9 wt% loading of PANI in SnO₂.