Dielectric, ferroelectric and impedance spectroscopic studies of Mn and W modified AgNbO3 ceramics

Muduli, Rakesh; Kumar, P.; Panda, Ranjit Kumar; Panigrahi, S.

doi:10.1016/j.matchemphys.2016.06.026

Cited by 12 publications

(16 citation statements)

References 29 publications

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“…Figure 2 shows the Raman spectra of AgNbO 3 , Co 3 O 4 and 10 wt.% composite. The Raman shifts obtained for bare AgNbO 3 and Co 3 O 4 well matched with the standard Raman bands [25,26]. The Raman intensity of the composite (10 wt.%) was observed to be lying in between AgNbO 3 and Co 3 O 4 .…”

Section: Fwhm Cossupporting

confidence: 69%

Heterojunction formation between AgNbO3 and Co3O4 for full solar light utilization with improved charge-carrier separation

Rani

Saravanan

2022

Photochem Photobiol Sci

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In the present study, the charge-carrier recombination of visible light active perovskite silver niobate (AgNbO 3 ) was reduced by forming heterojunction with Co 3 O 4 through simple impregnation and calcination route. The loading percentage of Co 3 O 4 was varied as 2, 5, and 10 wt.%. The XRD study revealed reduced interlayer spacing in the composite due to the replacement of the bigger Ag + ions by the smaller Co 2+ and Co 3+ ions of Co 3 O 4 . It was observed that the light harvesting efficiency of the materials was increased with increased loading of Co 3 O 4 . The TEM and XPS analysis confirmed the presence of Ag nanoparticles over the perovskite in the composite. The electrochemical analysis revealed enhanced charge-carrier number density and increased charge-carrier lifetime in the composite as a result of the presence of both silver and cobalt ions in the lattice. Further this enhanced charge-carrier separation of the composites was established through photocatalysis of Bisphenol-A under both solar and LED light. Charge-trapping study indicated *O 2 − and *OH as the major radicals involved and Z-scheme as the predominant charge transfer pathway for generation of these reactive oxygen species.

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Section: Fwhm Cossupporting

confidence: 69%

Heterojunction formation between AgNbO3 and Co3O4 for full solar light utilization with improved charge-carrier separation

Rani

Saravanan

2022

Photochem Photobiol Sci

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“…It is known that silver-based materials suffer a loss of silver at high calcination temperature. Therefore, to overcome this drawback, 3.0 wt% of Ag 2 O was added in excess to maintain the required stoichiometry [ 33 , 47 ]. The mixture was calcinated in air at 900 °C for 24 h, with a heating rate of 1 °C·min −1 .…”

Section: Methodsmentioning

confidence: 99%

Fabrication of ILs-Assisted AgTaO3 Nanoparticles for the Water Splitting Reaction: The Effect of ILs on Morphology and Photoactivity

et al. 2020

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The design of an active, stable and efficient photocatalyst that is able to be used for hydrogen production is of great interest nowadays. Therefore, four methods of AgTaO3 perovskite synthesis, such as hydrothermal, solvothermal, sol-gel and solid state reactions, were proposed in this study to identify the one with the highest hydrogen generation efficiency by the water splitting reaction. The comprehensive results clearly show that the solid state reaction (SSR) led to the obtainment of a sample with an almost seven times higher photocatalytic activity than the other methods. Furthermore, four ionic liquids, all possessing nitrogen in the form of organic cations (two imidazoliums with different anions, ammonium and tetrazolium), were used for the first time to prepare composites consisting of AgTaO3 modified with IL and Pt, simultaneously. The effect of the ionic liquids (ILs) and Pt nanoparticles’ presence on the structure, morphology, optical properties, elemental composition and the effectiveness of the hydrogen generation was investigated and discussed. The morphology investigation revealed that the AgTaO3 photocatalysts with the application of [OMIM]-cation based ILs created smaller granules (<500 nm), whereas [TBA] [Cl] and [TPTZ] [Cl] ILs caused the formation of larger particles (up to 2 μm). We found that various ILs used for the synthesis did not improve the photocatalytic activity of the obtained samples in comparison with pristine AgTaO3. It was detected that the compound with the highest ability for hydrogen generation under UV-Vis irradiation was the AgTaO3_0.2% Pt (248.5 μmol∙g−1), having an almost 13 times higher efficiency in comparison with the non-modified pristine sample. It is evidenced that the enhanced photocatalytic activity of modified composites originated mainly from the presence of the platinum particles. The mechanism of photocatalytic H2 production under UV-Vis light irradiation in the presence of an AgTaO3_IL_Pt composite in the water splitting reaction was also proposed.

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“…Various properties, such as dielectric, piezoelectric, ferroelectric, optical, electro-optic, etc, are reported to be strongly correlated to the structure of the crystallized oxide material. Since the report of ferroelectricity in BaTiO 3 in 1945, perovskite (ABO 3 ) structure has been studied extensively [1]. Till now, mostly lead-based materials remain the technologically important and extensively investigated class of ferroelectric oxides [2].…”

Section: Introductionmentioning

confidence: 99%

Microstructure and electrical properties of microwave sintered Nb-doped NBT ceramics

Sahu

Kumar

2021

PAC

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Nb5+-doped sodium bismuth titanate (NBT) ceramics ((Na0.5Bi0.5)1-x/2Ti1-xNbxO3 where x = 0, 0.005, 0.01 and 0.015) were obtained by microwave assisted solid state reaction route and microwave sintered at 1000 ?C. Microwave processing technique was chosen for the sintering as it is a powerfulmethod which enables sintering in a short time with fast heating rate avoiding grain growth. The influence of Nb5+-doping on microstructure and electrical properties of the NBT ceramics was studied. X-ray diffraction analyses revealed that solubility limit of niobium in NBT lattice is up to 1mol%, as with further increase in niobium concentration pyrochlore appeared. Microstructure of all the ceramics was investigated by field emission scanning electron microscopy and it was observed that the average grain size decreased with doping. Temperature dependent dielectric study was carried out for all the ceramics at different frequency. All ceramics show diffusive dielectric behaviour around Tm and introduction of Nb even increases compositional fluctuation compared to the parent NBT. Nb-doping shifts the Tm toward lower temperature. Leakage current study showed that for whole range of electric field ohmic type conduction mechanism is dominant for all the ceramics. Room temperature polarization-electric field (P-E) hysteresis loop confirms the ferroelectric behaviour of all the ceramics.

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Dielectric, ferroelectric and impedance spectroscopic studies of Mn and W modified AgNbO3 ceramics

Cited by 12 publications

References 29 publications

Heterojunction formation between AgNbO3 and Co3O4 for full solar light utilization with improved charge-carrier separation

Heterojunction formation between AgNbO3 and Co3O4 for full solar light utilization with improved charge-carrier separation

Fabrication of ILs-Assisted AgTaO3 Nanoparticles for the Water Splitting Reaction: The Effect of ILs on Morphology and Photoactivity

Microstructure and electrical properties of microwave sintered Nb-doped NBT ceramics

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