scholarly journals Synthesis and Characterization of Lead Free Calcium Bismuth Titanate (Ca0.25Bi0.5 TiO3) Piezoelectric Ceramics

Bismuth layer-structured piezoelectric (BLSP) calcium bismuth titanate (Ca0.25Bi0.5TiO3) piezoelectric ceramics have been prepared via a conventional sol gel reaction method by mixing the desired chemicals in stoichiometric amounts. Calcium bismuth titanate (CBT) samples were characterized by means of XRD, SEM and FTIR spectroscopy. X-ray diffraction (XRD) analysis revealed that CBT ceramics exhibit a single phase orthorhombic structure. The SEM images confirm its morphological size ranging from 1.00 to 2.75 µm. FTIR analysis reveals that calcium bismuth titanate has been prepared successfully, and the ratio of calcium, bismuth and titania was found to be 0.25:0.50:1.00, respectively. The photocatalytic removal of Methylene Blue, cadmium (Cd2+) and other toxic heavy metals will be carried out using CBT materials.

2021 ◽  
Vol 12 (4) ◽  
pp. 2523-2529
Author(s):  
Daniel Sam N ◽  
Anish C I ◽  
Sabeena G ◽  
Rajaduraipandian S ◽  
Manobala ◽  
...  

Sol gel methods were used for the study of the antimicrobial activity of Cd-TiO2 against gram-negative and positive bacteria. These Cd-TiO2 have been characterized by various optical and techniques. They have been exhibited by X-ray diffraction, scanning electron microscopy, ultraviolet spectroscopy, and infrared spectroscopy. The structures of the various XRD patterns indicate that the product has a structure. The particle size of Cd-TiO2 is 35nm. The SEM images confirm the spherical appearance of the sample. The energy X-ray spectra have been confirmed as well and then C, O, Ti, Cd, Pt element are present in Cd-TiO2. The weight percentage of Cadmium is 5.8%, Ti is 51.03%, C is 5.13% and O is 31.75% in Cd-TiO2. BET image shows that the major pore size distribution of Cd-TiO2 is ranged from 2.24 nm. The Cd-TiO2 that the antibacterial activity when tested against the pathogens only gram-negative bacteria such as Pseudomonas. The zone of minimum inhibition concentration was measured in a range of 20mm in 25μl and 30mm in 100μl.


2014 ◽  
Vol 997 ◽  
pp. 359-362 ◽  
Author(s):  
Chun Hong Ma ◽  
Xue Lin ◽  
Liang Wang ◽  
Yong Sheng Yan

Nanocrystalline bismuth titanate (Bi4Ti3O12; BTO) powders were successfully prepared by the sol-gel method, using bismuth nitrate (Bi(NO3)3·5H2O) and tetrabutyl titanate (Ti(OC4H9)4) as source materials, acetic anhydride and ethanediol as solvents. The thermal decomposition and phase inversion process of the gel precursors were studied by using differential thermal analysis (DTA). The crystal structures and microstructures of BTO powders were investigated by using x-ray diffraction (XRD), and transmission electron microscope (TEM). The crystallization of amorphous bismuth titanate has been discussed. The effect of sintering temperature on the structure and morphology of BTO was investigated. At 644 oC and above, BTO powder undergoes a phase transformation from tetragonal to orthorhombic. At 900 oC, the purified orthorhombic BTO nanocrystals were obtained.


2012 ◽  
Vol 581-582 ◽  
pp. 525-528
Author(s):  
Jia Feng Zhang ◽  
Bao Zhang ◽  
Xue Yi Guo ◽  
He Zhang Chen ◽  
Jian Long Wang ◽  
...  

The LiFe0.98Mn0.02PO4/C was synthesized by spray-drying and low temperature reduction route using FePO4•2H2O as precursor, which was prepared by a simple co-precipitation method. The LiFe0.98Mn0.02PO4/C sample was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemical measurements. The XRD analysis and SEM images show that sample has the good ordered structure and spherical particle. The charge-discharge tests demonstrate that the powder has the better electrochemical properties, with an initial discharge capacity of 162.1 mAh•g−1 and 155.8 mAh•g−1 at current density of 0.1 C and 1C, respectively. The capacity retention reaches 99.4% after 100 cycles at 1C.


Author(s):  
Trinh Thi Loan ◽  
Nguyen Ngoc Long

The SnO2:Ni2+ powders with dopant contents ranging from 0.0 to 12 mol% have been synthesized by sol-gel method. The samples were characterized by X-ray diffraction (XRD) Raman spectroscopy, energy-dispersive X-ray spectrometer (EDS) and photoluminescense (PL) spectra. XRD analysis showed that samples doped with low Ni- concentrations exhibited single SnO2 crystalline phase, whereas the samples with high Ni- concentrations exhibited a mixture of SnO2 and NiO phases. The lattice parameters of the SnO2 host were independent on Ni2+ dopant content, while Raman mode positions were dependenton Ni2+ dopant content. The PL spectrum of the undoped SnO2 was characterized by the emission peaks due to near band edge (NBE) emission and the violet emission peaks associated with surface dangling bonds or oxygen vacancies and Sn interstitials.


2016 ◽  
Vol 34 (3) ◽  
pp. 597-604 ◽  
Author(s):  
Shams Ali Baig ◽  
Zimo Lou ◽  
Malik T. Hayat ◽  
Ruiqi Fu ◽  
Yu Liu ◽  
...  

AbstractCalcination is considered to increase the hardness of composite material and prevent its breakage for the effective applications in environmental remediation. In this study, magnetic biochar amended with silicon dioxide was calcined at high temperature under nitrogen environment and characterized using various techniques. X-ray diffraction (XRD) analysis revealed elimination of Fe3O4 peaks under nitrogen calcination and formation of Fe3Si and iron as major constituents of magnetic biochar-SiO2 composite, which demonstrated its superparamagnetic behavior (>80 A2·kg−1) comparable to magnetic biochar. Thermogravimetric analysis (TGA) revealed that both calcined samples generated higher residual mass (>96 %) and demonstrated better thermal stability. The presence of various bands in Fourier transform infrared spectroscopy (FT-IR) was more obvious and the elimination of H–O–H bonding was observed at high temperature calcination. In addition, scanning electron microscopy (SEM) images revealed certain morphological variation among the samples and the presence of more prominent internal and external pores, which then judged the surface area and pore volume of samples. Findings from this study suggests that the selective calcination process could cause useful changes in the material composites and can be effectively employed in environmental remediation measures.


2008 ◽  
Vol 47-50 ◽  
pp. 1063-1066 ◽  
Author(s):  
Costel Birsan ◽  
Cristina Ghitulica ◽  
Ecaterina Andronescu ◽  
Cristina Ionita ◽  
Mihaela Birsan

The aim of the study was the synthesis and characterization of bioactive osteoinductive glasses, in the SiO2 – CaO – P2O5 system. In order to maintain the bioactive character of bioglasses, for SiO2 contents higher than 60%, the sol – gel method was used for preparation. On the obtained powders, thermal, grain size and X - ray diffraction analysis were performed. The X - ray diffraction emphasized the formation of phosphate phases, whose proportion decreases as the silica content is increased. Later, the powders were thermally treated at temperatures between 1000 and 14000C, the phase composition evolution being monitored through XRD analysis. On the powder suspensions in physiological serum, the evolution of pH was investigated, in order to establish the chemical stability. The behavior of the obtained powders in physiological medium was studied, by immersing samples in simulated body fluid and excerpted after different periods of time.


Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 736 ◽  
Author(s):  
Aurelija Smalenskaite ◽  
Lina Pavasaryte ◽  
Thomas Yang ◽  
Aivaras Kareiva

The Mg3/Al and Mg3/Al0.99Eu0.01 layered double hydroxides (LDHs) were fabricated using a sol-gel chemistry approach and intercalated with different anions through ion exchange procedure. The influence of the origin of organic anion (oxalate, laurate, malonate, succinate, tartrate, benzoate, 1,3,5-benzentricarboxylate (BTC), 4-methylbenzoate (MB), 4-dimethylaminobenzoate (DMB) and 4-biphenylacetonate (BPhAc)) on the evolution of the chemical composition of the inorganic-organic LDHs system has been investigated. The obtained results indicated that the type and arrangement of organic guests between layers of the LDHs influence Eu3+ luminescence in the synthesized different hybrid inorganic–organic matrixes. For the characterization of synthesis products X-ray diffraction (XRD) analysis, infrared (FTIR) spectroscopy, fluorescence spectroscopy (FLS), and scanning electron microscopy (SEM), were used.


2014 ◽  
Vol 925 ◽  
pp. 396-400 ◽  
Author(s):  
Robabeh Bashiri ◽  
Norani Muti Mohamed ◽  
Chong Fai Kait ◽  
Suriati Sufian

Titania (TiO2) as a semiconductor has been intensively studied during the last decades. Regardless of its superior photocatalytic performance and extensive environmental applications, it has a wide bandgap which lead to a photocatalytic activity only in ultraviolet (UV) irradiation. To shift the activity of TiO2 to visible region, a series of monometallic and bimetallic doped TiO2 was prepared with 10wt% total metals loading. The photocatalysts were synthesized by sol-gel associated via hydrothermal method. The properties of the photocatalysts such as crystal size, surface morphology, total surface area, chemical state of the elements, and bandgap were investigated by using thermogravimetric analysis (TGA), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) measurement. XRD analysis showed that all samples displayed anatase (101) as a main phase of TiO2 with average crystal size between 10-16 nm in a good agreement with the TEM results. The FESEM images show spherical particles less than 20 nm in size. The BET results indicated that all samples are mesoporous. The band gap of Ni-Cu/TiO2 is reduced to 2.65 eV with more absorbance in the visible region compared to those of cu/TiO2 and Ni/TiO2.


2021 ◽  
Author(s):  
Refad Ahmed ◽  
Hemen Deka

Abstract Biochemical and instrumental analysis was carried out for understanding the maturity and stability of the vermicomposted patchouli bagasse (PB) and cow dung (CD) mixtures. Two important enzymes namely urease and dehydrogenase were evaluated to understand the biological changes. On the other hand, instrumental study includes scanning electron microscopy (SEM) imaging; X-ray diffraction (XRD) pattern and UV-VIS spectrophotometer analysis of the vermicomposting end products. The results showed enhancement in urease (1.14-2.84 folds) and dehydrogenase (1.7-3.1 folds) activities confirming the maturity and stability of the vermicomposting end products. The spectrophotometric analysis revealed that there was significant decrease in humification index (1.5 to 3.4 folds) in the vermicompost samples than the initial level. The SEM images depicted the porous, fragmented and granular structure of end vermicompost samples. Further, the XRD analysis showed the micromorphological crystalline structure and enhanced decomposition of the substrate mixture during vermicomposting process. As a whole, the end vermicompost product was found to be much stable and mature for agronomic use.


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