scholarly journals Role of Al and Ti doping in modulating electrical properties of BIVOX system

2019 ◽  
Vol 8 (4) ◽  
pp. 489-499
Author(s):  
Diptimayee Tripathy ◽  
Amarjyoti Saikia ◽  
Gyati Tachang Tado ◽  
Arvind Pandey

AbstractThe doubly-doped bismuth vanadate with Al and Ti having formula unit, Bi2V1−xAlx/2Titx/2O5.5-δ (0.10 ⩽ x ⩽ 0.25) was synthesized. The specimens were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), differential scanning calorimetric (DSC), UV-Vis, and electrochemical impedance spectroscopy (EIS) for their structural, thermal, optical, and electrical studies. Influence of both dopant cations (Al and Ti) was observed in the gradual stabilization of the tetragonal phase of Bi2VO5.5-δ with dopant amount. A non-uniform grain growth phenomenon was observed up to x = 0.175, with dopant addition. UV-Vis study revealed the comparatively higher order of oxide ion vacancies for the composition x = 0.175. Impedance spectroscopy measurements indicate a significant decrease of both the grain (Rg) and grain boundary resistances (Rgb) with the rise in temperature and the overall resistance is found to be dominated by the grain interior contribution. Enhancement of ionic conductivity was found in all the compositions in the intermediate temperature range as compared to the parent compound, and the single Al-doped system and the highest value were obtained for x = 0.175.

2021 ◽  
Author(s):  
Sawsan A. Al-Hilifi ◽  
Rawdah M. Al-Ali

Abstract The recent interest in bio-packing at field of food become trending in the development of antimicrobial coatings. The focus of this study was to assess the potential application of zingiber officinale essential oil (GEO) in chitosan films (CHf). The data indicated that there were significant differences(p < 0.05) in the chemical composition of the samples.Forty-seven active compounds of the essential oil were identified from the rhizomes of ginger, which were identified byGC-MS. Fourier transforms infrared spectra (FT-IR) confirmed that an interaction between the hydroxyl groups of the phenolic compounds of the essential oil and the amide groups of polymer matrix. As shown the appearance of peaks at wavenumbers 1639cm-1 and 1558cm-1 Furthermore, X-ray diffraction results suggested a lower crystallintiyin CHf due to GEO effect. Differential Scanning Calorimetric (DSC) analysis revealed that CHf possessed high thermal stability, especially when different concentrations of GEO added. The bioactive CHf showed distinct activity against both positive and negative gram bacteria. They are Staphylococcus aurous, Bacillus subtillis, Streptococcus Sp. Escherichia coli, Salmonella Sp. Pseudomonas erugiosa. This results provides a comprehensive insight on the importance of films incorporated with EOs of interest in food packaging.


2012 ◽  
Author(s):  
Ανδρόνικος Μπαλάσκας

Υβριδικές επιστρώσεις οργανικά τροποποιημένων πυριτικών ενώσεων και εποξειδικώνρητινών (Organically Modified Silicates, ORMOSILs – epoxy) εφαρμόστηκαν στο κράμααργιλίου 2024-Τ3 και σε γαλβανισμένο χάλυβα σε υψηλές θερμοκρασίες (Hot Dip GalvanizedSteel, HDGS) προκειμένου αυτές να προστατεύσουν τα υποστρώματα από τη διάβρωση. Για τηνβελτίωση της αντοχής των επιστρώσεων στην διάβρωση ενσωματώθηκαν στην πολυμερικήμήτρα νανοπεριέκτες από μολυβδαινικό δημήτριο (CeMo) και οξείδιο του τιτανίου (TiO2),καθώς και pH-ευαίσθητα οργανικά νανοδοχεία πληρωμένα με τους αναστολείς διάβρωσης 2-μερκαπτοβενζοθειαζόλιο, 8-υδροξυκινολίνη, 1H-βενζοτριαζολο-4-σουλφονικό οξύ καιεξαφλουοροτιτανικό οξύ.Οι υβριδικές επιστρώσεις εφαρμόστηκαν στο υπόστρωμα με τη διαδικασία εμβάπτισης.Η μορφολογία των επιστρώσεων εξετάστηκε με ηλεκτρονική μικροσκοπία σάρωσης (ScanningElectron Microscopy (SEM)). Η σύνθεση και η δομή τους μελετήθηκε με υπέρυθρηΦασματοσκοπία μετασχηματισμού Fourier (FT-IR) και με μικροανάλυση με φθορισμομετρίαακτίνων Χ (Energy Dispersive X-Ray Analysis (EDX)). H ηλεκτροχημική φασματοσκοπίασύνθετης αντίστασης (Electrochemical Impedance Spectroscopy, EIS), η dc-πόλωση (dcpolarization)και η μέτριση ανοικτού δυναμικού (open circuit potential, OCP) χρησιμοποιήθηκανγια την αξιολόγηση των αντι-διαβρωτικών ιδιοτήτων των επιστρώσεων. Τα αποτελέσματαέδειξαν ότι οι επιστρώσεις με πληρωμένα νανοδοχεία έχουν αυξημένες αντιδιαβρωτικέςιδιότητες συγκριτικά με τις υπόλοιπες επιστρώσεις εμφανίζοντας και ιδιότητες αυτο-θεραπείας.Τέλος, συντέθηκαν νανόσφαιρες οξειδίου του χαλκού (Cu2O), οι οποίεςχαρακτηρίστηκαν με SEM, ηλεκτρονική μικροσκοπία διερχόμενης δέσμης (ΤransmissionΕlectron Μicroscopy (TEM)) και περίθλαση ακτίνων Χ (X ray Diffraction (XRD)). Οινανόσφαιρες στη συνέχεια πληρώθηκαν με ουσίες που δρουν ως βιοκτόνα και ενσωματώθηκανσε βαφές εμπορίου και σε επιστρώσεις βασισμένες σε εποξειδικές ενώσεις και μελετήθηκε ηδράση τους ως αντιαποθετικά αντιδραστήρια. Τα αποτελέσματα έδειξαν ότι οι επιστρώσεις μεπληρωμένες νανόσφαιρες Cu2O είχαν μεγαλύτερη αποτελεσματικότητα σε σύγκριση με τιςβαφές εμπορίου με βιοκτόνα μετά από έκθεση σε θαλάσσιο περιβάλλον.


NANO ◽  
2020 ◽  
Vol 15 (07) ◽  
pp. 2050089
Author(s):  
Litong Niu ◽  
Shaoping Hu ◽  
Yali Ma ◽  
Mingming Wang ◽  
Bolin Lv ◽  
...  

Novel ZnIn2S4/FeUiO-66 (ZFeU) photocatalyst with different proportion of FeUiO-66 has been successfully prepared by a facile one-pot solvothermal reaction. The as-synthesized nanocomposites have been thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Brunauer–Emmett–Teller (BET) characterization, photoluminescence (PL) analysis and electrochemical impedance spectrum (EIS). The photocatalytic performance of ZFeU nanocomposites for the photodegradation of RhB under visible light irradiation was better than that of ZnIn2S4 and FeUiO-66 alone. The experiment results showed the 20% ZFeU nanocomposites had the best photocatalytic properties. At the same time, a probable mechanism was discussed and it was believed that introduction of FeUiO-66 on ZnIn2S4 would minimize the recombination of photogenerated electron-hole pairs, leading to the enhancement of the photocatalytic activity.


Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 903 ◽  
Author(s):  
El-Sayed M. Sherif ◽  
Sameh A. Ragab ◽  
Hany S. Abdo

The manufacturing of different Ti-6Al-xV (x = 2, 4, 6, and 8 wt.%) alloys using a mechanical alloying technique was reported. The corrosion behaviors of these newly fabricated alloys after 1, 24, and 48 h exposure to a simulated body fluid (SBF) were assessed using cyclic potentiodynamic polarization, electrochemical impedance spectroscopy, and chronoamperometric measurements. Surface morphology and elemental analyses after corrosion for 48 h in SBF were reported using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) examinations. An X-ray diffraction investigation characterized the phase analyses. All results indicated that the increase of V content significantly decreases both uniform and pitting corrosion. This effect also increases with prolonging the immersion time to 48 h before measurement.


2020 ◽  
Vol 22 (20) ◽  
pp. 11467-11473 ◽  
Author(s):  
Apurba Mahapatra ◽  
Rashmi Runjhun ◽  
Jan Nawrocki ◽  
Janusz Lewiński ◽  
Abul Kalam ◽  
...  

We have studied the effect of guanidinium incorporation in a single-crystalline MAPbI3 perovskite on ion migration using temperature-dependent electrochemical impedance spectroscopy.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
T. Prakash ◽  
R. Jayaprakash ◽  
G. Neri ◽  
Sanjay Kumar

ZnO nanostructures have been successfully prepared by a microwave irradiation method. The role of albumen as a template in addressing the size and morphology of ZnO has been investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG-DTA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. A heterogeneous mixture of Zn(OH)2 and ZnO was obtained in absence of albumen. Pure ZnO nanostructures, consisting of rod- and whisker-like nanoparticles embedded in a sheet matrix, were obtained in the presence of albumen. Optical and photoluminescence (PL) properties of the synthesized samples were also compared. Results obtained indicate that the microwave-assisted method is a promising low temperature, cheap, and fast method for the production of ZnO nanostructures.


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