Field Emission Scanning Electron Microscopy Studies Research Articles

Synthesis and Characterization of Gold Nanoparticles and Gold Nanoparticles Loaded with Bromelain

The production and use of nanometallic elements, such as gold, have received a lot of attention lately due to their distinctive features and wide range of uses. Most of these studies have employed the Turkevich approach. This research employed the Turkevich technique to produce gold nanoparticles (AuNPs). AuNPs and bromelain-loaded AuNPs were characterised using a variety of methods, including ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and zeta potential (ZP) measurements. The UV-Vis spectra of Bromelain, AuNPs, and AuNPs-Bromelain each had a peak at 276, 534, and 550 nm wavelengths, respectively. The FE-SEM and TEM studies revealed the presence of spherical particles with a smooth surface. The diameters of the AuNPs ranged from 49.32 to 77.29 nm; the diameters of the Bromelain-AuNPs ranged from 46.39 to 75.66 nm, as determined by the FE-SEM analysis. The TEM analysis indicated that the particles' sizes ranged from 7.40 to 15 nm for AuNPs and 14.51 nm for AuNPs-Bromelain. The XRD patterns revealed numerous diffraction peaks, indicating the crystal structure of the synthesised nanoparticles. FTIR spectrometry was employed to identify the functional groups in the synthesised nanoparticles. Zeta potential (ZP) measurements revealed that AuNPs had a zeta potential value of +0.1±0.4, and the zeta potential value for AuNPs-Bromelain was +1.2±3.0 mV.

Effect of Cetyl Pyridinium Chloride on Corrosion Inhibition of Mild Steel in Acidic Medium

The corrosion inhibition behavior of cetyl pyridinium chloride (CPC) on mild steel (MS) in 0.5M H2SO4 solution was examined using weight loss and potentiodynamic polarization method. Different concentrations of CPC (0.000192M, 0.0038M, 0.0057M and of 0.0077M) was used to find the balanced CPC in the acid solution. Among them, 0.000192M and 0.0077M of CPC solution showed a corrosion rate of 8.23×10-3, 3.52×10-5 (mm/Year), and the inhibition efficiency of 89.94% and 96.23%, respectively, which is lower than the pure acidic solution (0.5M H2SO4). Furthermore, the experimented MS surfaces were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Atomic Force Microscopy (AFM). FESEM and AFM studies demonstrated the corrosion attack on the MS surface, which is relatively less as compared to the only acid-exposed surface. The SEM-EDX analysis confirmed the presence of nitrogen oxide on the surface, which might be contributed by the protonation of pyridinium group of CPC might adsorbed at the MS surface to prevent iron dissolution.

Characteristics of the incorporation of Yb defect states in CuO:ZnO nanocomposite

Exploring magnetic order in nonferromagnetic substances, such as CuO:ZnO, becomes especially attractive when introducing defect states through nonmagnetic ion doping. In this study, we delved into the impact of Yb doping on the structural, morphological, optical, and magnetic properties of CuO:ZnO. The Yb doped CuO:ZnO was prepared with different Yb concentrations (x = 0.00–20 %) via the temperature-assisted co-precipitation method. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), UV–Vis spectroscopy, and vibrating sample magnetometer (VSM) were used to investigate the structural, morphological, optical, and magnetic properties of Yb doped CuO:ZnO nanocomposites.The incorporation of Yb in CuO:ZnO nanocomposites leads to a notable shift of the characteristic XRD peaks of CuO and ZnO to lower angles, accompanied by an increase in the lattice parameters. UV–visible absorption spectroscopy shows an overall decrease in the optical band gap energy of ZnO as the Yb defect level increases. FE-SEM studies revealed the transformation of spherical structures into agglomerated non-spherical structures upon the introduction of Yb ions into CuO:ZnO nanocomposites. According to XPS data, the predominant valences of Yb-doped CuO:ZnO nanocomposites are Zn2+, Cu2+, and Yb3+. One noteworthy observation from the XPS results is that, in comparison to the intensity of OL or Oad peaks, the intensity of OV (Oxygen vacancy) defect peak increases when the Yb impurity concentration increases. Magnetic measurements demonstrated a diamagnetic order in pure ZnO, which converts to a ferromagnetic order with the incorporation of Yb defect states. The ferromagnetic properties of the Yb-doped CuO:ZnO nanocomposite can be ascribed to the exchange interaction of Yb3+ ions with defect states (Oxygen Vacancy) in ZnO and CuO.

Green synthesis of copper(II) oxide nanoparticles covered on multiwalled carbon nanotubes modified screen-printed electrode as rapid electrochemical sensing platform for detection of doxepin

In the current research, a modified screen-printed electrode has been made by depositing a copper(II) oxide nanoparticle upon the surface of multiwalled carbon nanotubes (CuO/MWCNTs). Through the use of X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), and mapping, the characterization of the CuO/MWCNTs modifier was examined. The XRD analysis confirms the in-situ formation of copper(II) oxide nanoparticles with MWCNT. FESEM studies reveal the simultaneous existence of nanoparticles and nanotubes in the prepared nanocomposite material. This kind of morphological orientation has significantly improved the nanocomposite’s catalytic properties. Moreover, EDS analysis and elemental mapping depicts that the presence of nanocomposite containing the elements of Cu, O, and C mentioned. Examining the modified electrode's electrochemical activity revealed good stability and conductivity under a diffusion-controlled procedure, making it an ideal working electrode. Additionally, the doxepin oxidation process at the modified electrode’s surface, an antidepressant medicine, has been examined. The modified electrode had a high doxepin sensitivity at an applied voltage of 780 mV. With a detection limit of 0.17 nM (signal/noise = 3), linear range was also obtained over a wide concentration range of 0.001 µM to 400.0 µM (R2 = 0.9998). What's more, the modified electrode is very resistant to ion poisoning and efficiently prevents interference from the oxidation of typicalinterfering species. Moreover, the CuO/MWCNTs electrode has been utilized to measure the doxepin concentration in actual samples. Aside from having an improved electrocatalytic capability, the modified electrode also has a low working potential and good stability, as well as high sensitivity.

Recovery and Reuse of Chromium from Tan Yard Solid Waste in Leather Manufacturing

Chrome tanning is the most popular and widely used method utilizing basic chromium salts in leather processing. Only 60-70% of these salts react with collagen to form leather. The rest remains unreacted being released as toxic waste and causing severe environmental pollution in many developing countries. In the current study, a significant approach was made to utilize solid waste with a clean environment perspective. The chromium was extracted as basic chromium sulfate using H2SO4 from tannery waste and reused in the leather manufacturing procedure. Extracted solid sludge was examined by Atomic Absorption Spectrometry and elemental analysis before and after the separation of chromium (III). It revealed that 97% of chromium was extracted from tan yard sludge. Recovered chromium sulfate was reused in goat skin processing. Batch experiments were carried out by applying recovered basic chromium sulfate, and a combination of fresh and recovered basic chromium sulfate solutions separately. Fresh basic chromium sulfate was used as the control method. The structure and morphology of the final processed leather were characterized by Field Emission Scanning Electron Microscope (FESEM) and Thermogravimetric analysis (TGA). The identical structural morphologies of all processed leather were confirmed in the FESEM study. The physical and chemical characteristics of all finished leather were found very similar. The TGA analysis data proved that raw leather processed by recovered chromium is thermally more stable than others. These research findings signify a new potential effort of separating important chemicals from solid sludge and reusing them. This technique is simple, cost-effective, eco-friendly, and sustainable as it reduces environmental pollution from tannery chromium waste.

Investigation of Cannabinoid Acid/Cyclodextrin Inclusion Complex for Improving Physicochemical and Biological Performance.

This study aimed to investigate the enhancement of cannabinoid acid solubility and stability through the formation of a cannabinoid acid/cyclodextrin (CD) inclusion complex. Two cannabinoid acids, tetrahydro-cannabinolic acid (THCA) and cannabidiolic acid (CBDA), were selected as a model drug along with five types of CD: α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), and methylated-β-cyclodextrin (M-β-CD). Phase solubility studies were conducted using various types of CD to determine the complex stoichiometry. The preparation methods of the CD inclusion complex were optimized by adjusting the loading pH solution and the drying processes (spray-drying, freeze-drying, spray-freeze-drying). The drying process of the cannabinoid acid/M-β-CD inclusion complex was further optimized through the spray-freeze-drying method. These CD complexes were characterized using solubility determination, differential scanning calorimetry (DSC), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and 1H NMR spectroscopy. DSC, XRD, and FE-SEM studies confirmed the non-crystalline state of the cannabinoid acid/CD inclusion complex. The permeation of THCA or CBDA from the M-β-CD spray-freeze-dried inclusion complex was highly improved compared to those of cannabis ethanolic extracts under simulated physiological conditions. The stability of the cannabinoid acid/M-β-CD inclusion complex was maintained for 7 days in a simulated physiological condition. Furthermore, the minimum inhibitory concentration of cannabinoid acid/M-β-CD inclusion complex had superior anti-cancer activity in MCF-7 breast cancer cell lines compared to cannabinoid acid alone. The improved physicochemical and biological performances indicated that these CD inclusion complexes could provide a promising option for loading lipophilic cannabinoids in cannabis-derived drug products.

Preparation characterization and photocatalytic activity of SF-ZnO nanocomposite

This article describes the fabrication of zinc oxide nanoparticles (ZnO-NPs) incorporating silk fibroin (SF) nanocomposite and its characterization. The optical, structural and morphological features of fabricated nanocomposite film were reviewed by using UV–Visible spectroscopy (UV–Vis), X-ray diffraction measurement (XRD), field emission scanning electron microscopy (FE-SEM) with energy dispersive spectroscopy (EDS) experimental techniques. The UV–Vis absorption spectrum revealed presence of zinc oxide nanoparticles in the SF film with absorption peak at λ = 362 nm. The presence of zinc oxide nanoparticles in composite film was confirmed by diffraction peaks found at scattering angle at 2θ = 35.13°, 55.32°, 62.06°, 67.10° and 68.53° respectively. The FE-SEM study showed native SF has very smooth surface morphology, whereas the SF-ZnO nanocomposite film exhibited rough surface. The ZnO-NPs present in the sample were spherical in shape. Further, the photocatalytic activity of SF-ZnO-NCs film was evaluated by observing the photo-degradation of the textile dye methylene blue (MB) under UV-B light irradiation. The maximum degradation efficiency was nearly 84 % within 340 min. The results obtained suggested that SF-ZnO-NCs film could be used as a photocatalytic material in the treatment of textile waste water.

Nanoarchitectonics of tin telluride: A novel pseudocapacitive material for energy storage application

In this study, we presented the synthesis of tin telluride (SnTe) nanoparticles and reduce graphene oxide mixed with SnTe (rGO/SnTe) nanocomposite through the hydrothermal technique. The rGO with various contents (0, 5 and 10%) has been added in SnTe and nominated as ST, STG-1 and STG-2 respectively for electrode materials of supercapacitor. The prepared materials were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FESEM), Cyclic voltammetry (CV), Charging/discharging (GCD) and Brunauer–Emmett–Teller (BET) analysis. XRD patterns approve SnTe form a cubic crystal phase. Based on the FTIR results Sn–Te vibration modes was observed in pure SnTe and in rGO/SnTe composite some vibration mode were disappeared at 10% rGO content. FESEM study presences samples exhibit spherical like shapes morphology with wide space and the average grain size is in between 45 and 32 nm. EDX analysis confirm the stoichiometry of the electrode materials. The specific capacitance (SC) for SnTe electrode 623 Fg-1 rises to 1316 Fg-1 with 10% rGO/SnTe nanocomposite, which specifies that rGO has improved the electrochemical characteristics of SnTe nanoparticles. The rGO/SnTe nanocomposite electrode has the highest specific energy density and specific power density value of 16 Wh/kg and 3748 W/kg, respectively with columbic efficiency retention is 92.2% after 1000 cycles. These outcomes collectively indication that SnTe/rGO nanocomposite have extensive application prospects.

Silver Decorated and Graphene Wrapped Polypyrrole@Ni(OH)2 Quaternary Nanocomposite for High Performance Energy Storage Devices.

In this work, silver (Ag) anchored over graphene (GN) wrapped polypyrrole (PPy)@ nickel hydroxide (Ni(OH)2) nanocomposites were synthesized through a combination of oxidative polymerization and hydrothermal processes. The synthesized Ag/GN@PPy-Ni(OH)2 nanocomposites were characterized for their morphological characteristics by field emission scanning electron microscopy (FESEM), while the structural investigations were done by X-ray diffraction and X-ray photoelectron spectroscopy (XPS). The FESEM studies showed Ni(OH)2 flakes and silver particles attached over the surface of PPy globules, along with the presence of GN sheets and spherical silver particles. The structural analysis also showed the presence of constituents, i.e., Ag, Ni(OH)2, PPy, GN, and their interaction, therefore vouching that the synthesis protocol is efficacious. The electrochemical (EC) investigations were done in potassium hydroxide (1 M KOH) using a three electrode setup. The quaternary Ag/GN@PPy-Ni(OH)2 nanocomposite electrode showed the highest specific capacity of 237.25 C g-1. The highest electrochemical performance of the quaternary nanocomposite is associated with the synergistic/additional effect of PPy, Ni(OH)2, GN, and Ag. The assembled supercapattery with Ag/GN@PPy-Ni(OH)2 as a positive and activated carbon (AC) as a negative electrode displayed eminent energy density of 43.26 Wh kg-1 with the associated power density of 750.00 W kg-1 at a current density of 1.0 A g-1. The cyclic stability of the supercapattery (Ag/GN@PPy-Ni(OH)2//AC), comprising a battery-type electrode, displayed a high cyclic stability of 108.37% after 5500 cycles.

Microscopic studies on transparent AlSiN ternary hard coating

In this work AlSi nanocomposite coating were deposited by RF magnetron sputtering in Ar/N2 reactive atmosphere. AlSi alloy target of composition 86:14 wt % have been used to deposit the coating on float glass substrate by varying the deposition time: starting from 0.5 h to 2 h. The substrate temperature and target power were fixed at 250 °C and 100 W respectively. The effect of deposition time on microstructure, mechanical and optical property were studied by usingX-ray Diffraction (XRD), Stylus profiler, Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), Transmission Electron Microscopy (TEM), UV–Visible Spectrometer and Nanoindentation techniques. The XRD shows the formation h-AlN phase for film deposited for 2 h which shows that with increase in deposition time, the film structure changes from amorphous to polycrystalline, the coating deposited for 2 h develops wurtzite-AlN nanocrystalline structure. The thickness of the coating increases with respect to the increasing deposition time which was confirmed from stylus profiler. The FESEM study shows the uneven and randomly oriented grains present in the coating. TEM study confirms the amorphous and polycrystalline nature of the films with low and high thickness respectively. The elemental composition was confirmed by EDS. UV–Visible Spectrometer delivers the optical transparency of the film which is >90% for all the coatings in the visible range spectra. The roughness of the samples was also measured from scanning probe microscope image, which showed average roughness (Rã) value below 2 nm. The maximum hardness obtained is 31 GPa for the coating deposited 2 h with 490 nm thickness, it has an elastic recovery of 92% which suggest its resistance to elasticity as well as plastic deformation.

Photocatalytic Degradation of Textile Orange 16 Reactive Dye by ZnO Nanoparticles Synthesized via Green Route Using Punica Granatum Leaf Extract

Since it does not use any dangerous chemicals and is a simple, low-cost process, the green synthesis approach for nanoparticle creation has several benefits compared to the physical and chemical synthesis routes. The current study describes an environmentally friendly synthesis of zinc oxide (ZnO) nanoparticles (NPs) using an extract of Punica granatum plant leaves. Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible spectrophotometer (UV-Vis), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy, and X-ray diffraction techniques were used to characterize the morphology, composition, and structural properties of the synthesized zinc oxide nanoparticles. The XRD pattern reveals that the ZnO nanoparticles are crystalline and have a diameter of 20 nm. According to the FESEM studies, the ZnO-NPs have sizes ranging from 50 to 100 nm on average and are almost spherical. When exposed to direct sunlight, the produced ZnO-NPs demonstrate impressive photocatalytic oxidation of textile Orange 16, a reactive dye. As a result, our research advances the development of a green photocatalyst for the removal of harmful dyes from water.

The Impact of Gold Nanoparticles Synthesized by Essential Oil of Lemon and Plasma Jet Scheme on Growth Inhibition of Breast Cancer Cells

Gold nanoparticles (AuNPs) have gained significance due to their size and shape. The current study aimed to prepare AuNPs by using green - plasma jet and calculate the cellular toxicity of those manufactured nanomaterials. Aqueous gold tetrachloride salts (HAuCl<sub>4</sub>·4H<sub>2</sub>O) and essential oil of lemon peels in different ratios (0:10, 1:9, 2:8, and 3:7) were used to produce AuNPs. The synthesized green-prepared gold was characterized by ultraviolet-visible (UV-vis), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). UV-vis spectrum showed the highest absorption at 540 nm, and the patterns of XRD at the ratio (2:8) showed four peaks occurred at peaks at 2θ = 38.1, 44.3, 64.5, and 77.98. FESEM study illustrated that the AuNPs particle sizes range between (38-76 nm). The cell toxicity results have shown the effectiveness of the green synthesized AuNPs on the breast cancer (AMJ13) cell line. The breast cancer (AMJ13) cell line is found to be more inhibited when the concentration of AuNPs reaches 100%. According to the findings, creating nanoparticle materials for the therapy of breast cancer cells using green-cold plasma is a potential technique.

Effect of anionic, cationic and non-ionic surfactants with NaF as binary additives on the performance of soluble lead redox flow battery

The effect of adding sodium lignosulfonate as anionic, hexadecyltrimethylammonium p-toluene sulfonate (HDTMA p-TS) as cationic, or Triton X-100 as non-ionic surfactant along with NaF into the electrolyte as binary additives on the performance behaviour of a soluble lead redox flow battery (SLRFB) is studied by Field Emission Scanning Electron Microscopy (FESEM) and various electrochemical techniques. The FESEM studies show no significant change in the structural morphology of PbO2 deposits in the case of cationic surfactant in conjunction with NaF, whereas sodium lignosulfonate and Triton X-100 in conjunction with NaF show significant changes in the morphology of cathode deposits. FESEM studies reveal that cationic surfactant with NaF facilitates the smooth and lateral growth of Pb deposits. Cyclic voltammetry and kinetic studies show that adding NaF to anionic surfactant is detrimental, while it is found to be beneficial with cationic and non-ionic surfactants. The constant current charge and discharge cycling studies show that cells with pristine electrolyte, anionic surfactant along with NaF, Triton X-100 along with NaF additives show a cycle-life of 25, 75, and 25 cycles, respectively, when charged at 20 mA cm−2 current density and discharged to 0.8 V at the same current density. Interestingly, the cationic surfactant with NaF exhibits a cycle-life of more than 1350 cycles without any maintenance with no deterioration in the performance under similar conditions. To the best of our knowledge, this is the highest cycle-life demonstrated for SLRFB system without any maintenance. Mechanistic insights for the beneficial role of cationic surfactant in controlling Pb dendrite formation are discussed.

Anthraquinone-2-sulfonic acid-loaded polyaniline nanostructures: Construction of symmetric supercapacitor electrodes thereof

Polyaniline (PANI) nanostructures were synthesized via an acid-free green route using redox-active, water-soluble 9,10-Anthraquinone-2-sulfonic acid sodium salt (AQSA). As a counter anion for the PANI backbone, the AQSA plays an important role in polyaniline (PANI) chain growth and as a morphology regulator. The AQSA doped PANI shows pronounced specific capacitance with effective cycling stability. As-synthesized nanotubular structures of PANI_AQSA (0.5, 1.0, and 1.5) with various concentration ratios of aniline to AQSA were achieved in appreciable yield. The intrinsic physico-chemical properties were analyzed using various physico-analytical techniques such as Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), powder X-ray diffraction analysis (XRD), Fourier Transmission Infrared spectroscopy (FT-IR), X-ray Photo Electron Spectroscopy (XPS), and Raman analysis. Nanotubular structures of PANI_AQSA were analyzed using FESEM studies. The electrochemical studies, galvanostatic charge-discharge (GCD), and Electrochemical impedance spectroscopy (EIS) were methodically investigated. PANI_AQSA_1.5 portrays enhanced specific capacitance of 440 Fg−1 at 1 Ag−1 (three-electrode system) in 1 M sulphuric acid electrolyte than its regular Cl− counter ion (276 Fg−1 at 1 Ag−1). The fabricated symmetric PANI_AQSA//PVA_H2SO4//PANI_AQSA supercapacitor showed a specific capacitance of 391 Fg−1 at 1 Ag−1 with 93 % capacitance retention for ~1000 cycles.

In-situ polymerization of polycarbazole-zinc oxide nanocomposite: An in silico docking model and in vitro antibacterial biomaterial

The current study focuses on the synthesis of polycarbazole-zinc oxide (PCz/ZnO) nanocomposite and its application as an in vitro antibacterial biomaterial as well as an in silico docking model. The synthesized pristine polymer, polycarbazole (PCz) and its nanocomposite PCz/ZnO were characterized by Fourier transform infrared (FT-IR), Thermo-gravimetry/Differential Thermo-gravimetry (TG-DTG), X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Brunauer-Emmett-Teller (BET), Energy-dispersive X-ray (EDX), Raman and X-ray photoelectron spectroscopic (XPS) techniques. FT-IR, XRD, FE-SEM, and XPS studies revealed that the polymerization of Cz has been successfully achieved on the surfaces of ZnO nanoparticles, indicating the strong interfacial interaction between PCz and ZnO nanoparticles. However, TG-DTG studies revealed that the nanocomposite, PCz/ZnO, proved thermally more stable compared to the pristine polymer, PCz. Further, the pristine PCz and PCz/ZnO nanocomposite were evaluated for antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus. The nanocomposite PCz/ZnO showed the highest zone of inhibition against K. Pneumoniae (17 mm), followed by P. aeruginosa (16 mm), then S. aureus (14 mm) and E. coli (19 mm) at 80 mg ml−1. Significantly, the in silico molecular docking predicts the modes of interactions of PCz and PCz/ZnO with B-DNA. Briefly, the results obtained from in silico molecular docking studies of the pristine PCz and PCz/ZnO nanocomposite with negative free binding energies (-7.1 kcal mol−1 of PCz and −6.23 kcal mol−1 of PCz/ZnO) imply an excellent and favourable binding affinity vis-à-vis interaction modes of both pristine PCz and PCz/ZnO nanocomposite (drugs) with B-DNA bases (target).

Green fabrication and characterization of transition metal doped tin dioxide nanoparticles using Psidium guajava leaf extract

The microwave-assisted green fabrication of tin dioxide (SnO2), iron (Fe)-doped tin dioxide (SFO), nickel (Ni)-doped tin dioxide (SNO) and cobalt (Co)-doped tin dioxide (SCO) nanoparticles (NPs) was illustrated employing Psidium guajava leaf extract (PGLE). The fabricated NPs were characterized by X-ray powder diffraction (XRD), Field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Energy-dispersive X-ray spectroscopy (EDAX) and Photoluminescence (PL) spectroscopy. XRD patterns of fabricated SnO2, SFO, SNO and SCO NPs show a rutile structure. FESEM study suggests that the fabricated NPs are spherical structure. The XPS scan validated the oxidation states of O (1s), Sn (3d), Fe (2p), Ni (2p) and Co (2p). In PL investigations, transition metals (Fe, Ni and Co)-doped SnO2 NPs enhance PL intensity compared with pure SnO2 NPs. PL spectroscopy shows that transition metals (Fe, Ni and Co)-doped SnO2 NPs enhance the PL intensity compared with pure SnO2 NPs. Employing Williamson-Hall (W-H) equations and W-H plotting method, the physical parameters of strain and stress are computed.

Preparation of polyvinyl chloride (PVC) membrane blended with acrylamide grafted bentonite for oily water treatment

The current work aims to advance the hydrophilicity, morphology, and antifouling characteristics of polyvinyl chloride (PVC) membranes for oily wastewater separation by incorporating modified bentonite. The surface of bentonite nanoparticles is altered by adopting the “grafting from” method using the surface-initiated atom transfer radical polymerization (SI-ATRP) approach. The PVC-based membrane is first prepared by blending acrylamide grafted bentonite (AAm-g-bentonite). AAm is grafted on bentonite in the presence of 2,2′-Bipyridyl and copper (I) bromide as a catalyst. The modified bentonite nanoparticles are studied using multiple techniques, such as fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), sedimentation tests, field emission scanning electron microscope (FE-SEM), etc. Flat-sheet PVC-based membrane is prepared by blending AAm-g-bentonite using the nonsolvent induced phase separation (NIPS) technique. Different methods, including FE-SEM, FTIR, sedimentation test, contact angle, porosity, antifouling property, and filtration studies of pure and oily water, are used to characterize and determine the performance of mixed-matrix membranes. Membrane performance is improved in the presence of modified bentonite (i.e., AAm-g-bentonite), with the best result achieved at PVC/AAm-g-ben-8 (i.e., 8 wt % of AAm-g-bentonite). Enhanced pure water flux (293.14 Lm−2h−1), permeate flux (123.96 Lm−2h−1), and oil rejection >93.2% are obtained by the reduced contact angle (49.1°) and improved porosity (71.22%).

Activation of zirconia nanophosphors with Eu3+ to demonstrate multifunctional optical applications

Pristine ZrO2 and Eu3+ activated ZrO2 nanophosphors were synthesized by urea assisted solution combustion method. The synthesized nanophosphors were characterized by Powder X-ray diffraction (PXRD), Field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and photoluminescent (PL) spectroscopy for their structural, morphological, surface, vibrational and luminescent studies. The crystal structure and phase transformation were studied by PXRD which was supported well by XPS and FTIR results. FESEM studies reveal the porous morphology due to the combustion synthesis. XPS results reveal that activator Eu was predominantly present in the +3 oxidation state in the nanpohosphor. PL emission spectra of Eu3+ activated zirconia show characteristic reddish emission corresponding to 5D0→7FJ (J = 0, 1, 2, 3, and 4) transitions of Eu3+ ion. Photometric parameters were calculated to check the possible application of the nanophosphors for solid-state lighting. The high color purity ∼94% of the synthesized phosphors indicates their application in phosphor-converted white light-emitting diodes (pc-wLEDs). The fluorescence intensity ratio (FIR) of non-thermally coupled levels 5D0→7F2 and 5D0→7F3 were used to calculate the temperature. At 623 K, a maximum relative and absolute sensitivity of 0.11% K−1, and 0.76% K−1 was observed. The possible anti-counterfeiting application of ZrO2:Eu3+ has been tested using a standard screen-printing procedure. The high contrast fingerprints of the synthesized phosphor taken under near-ultraviolet (n-UV) light indicate that the synthesized phosphor can be used for latent fingerprinting applications. All these results indicate that Eu3+ activated zirconia has the potential to be used as multifunctional material.

Modification of hydroxyapatite coating in the presence of adipic acid for Mg-based implant application

This study investigated the role of adipic acid (AA) in improving the anti-corrosion performance and in-vitro bioactivity of hydroxyapatite coating applied on AZ31 Mg alloy. Firstly, hydroxyapatite (HA) coating was applied on the AZ31 Mg alloy. In the next step, the optimized hydroxyapatite-based coating, modified with adipic acid by direct addition and post-treatment methods. Corrosion behavior of uncoated sample and different coated samples were studied by Electrochemical Impedance Spectroscopy (EIS) and Direct Current (DC) Polarization techniques. Surface characterization was examined by Field Emission Scanning Electron Microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDXS), X-ray diffraction (XRD) and contact angle measurements. According to the contact angle results, all coated samples reveal high hydrophilic behavior. Additionally, the XRD analysis confirms the formation of hydroxyapatite crystals in all coated samples and the presence of the AA in HA + AA and HA − AA coatings does not change the crystal structure of the hydroxyapatite. Electrochemical studies display that the Rp value of HA coating is increased from 3630 Ω.cm2 to 10784 Ω.cm2 by the direct addition method also by the post-treatment method the polarization resistance reached 10294 Ω.cm2. In addition, an in-vitro bioactivity assessment was performed in a simulated body fluid (SBF). Based on FE-SEM studies, a protective layer of AA is formed on HA coating by the post-treatment method which improves the anti-corrosion behavior efficiently. The results showed that the adipic acid-modified hydroxyapatite coatings by direct addition and post-treating methods display better anti-corrosion properties and bioactivity compared to the optimal hydroxyapatite coating.

Sn(IV) Porphyrin-Based Ionic Self-Assembled Nanostructures and Their Application in Visible Light Photo-Degradation of Malachite Green

A series of porphyrin-based ionic complexes were prepared through the reaction of two porphyrin precursors, 5,10,15,20-tetrakis(4-(2-pyridyl)phenyl)porphyrin H2TPhPyP (1) and trans-dihydroxo [5,10,15,20-tetrakis(4-(2-pyridyl)phenyl)porphyrinato]tin(IV) Sn(OH)2TPhPyP (2), with various acids (HCl, HNO3, CF3COOH, H2SO4, H2CO3, and H3PO4). The complexes were characterized via elemental analysis, 1H nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry, Fourier transform infrared (FT-IR) spectroscopy, ultraviolet (UV)-visible spectroscopy, fluorescence spectroscopy, and field-emission scanning electron microscopy (FE-SEM). Each compound exhibited different results for UV-visible, fluorescence, FT-IR, and FE-SEM studies depending on the counter anions. The complexes possessed different self-assembled nanostructures based on electronic interactions between the cations of compounds 1 and 2 with different counter anions. These aggregated species are stabilized by electrostatic forces and the π-π stacking interactions between the two porphyrin rings, in which the counter anions play an important bridging role. The counter anions also play an important role in controlling the morphology and photocatalytic properties of the as-developed materials. The complexes were then used for the photocatalytic degradation of the malachite green (MG) dye in aqueous media under visible light irradiation for up to 70 min. A morphology-dependent photocatalytic degradation of the MG dye was observed for all the ionic complexes, with efficiencies ranging from 50% to 95%.