Characterization of Philippine natural bentonite

Philippine natural bentonite is characterized using X-ray diffractometer (XRD), scanning electron microscope (SEM), chemical analysis, thermogravimetric-differential scanning calorimetry (TG-DSC), and Fourier transform infrared (FTIR) analysis. The cation exchange capacity (CEC) was also measured. XRD shows that the mineral is composed primarily of mordenite, hectorite, and montmorillonite. SEM shows the flaky and porous structure of the bentonite powder. Chemical analyses show that SiO2 (47.90 wt%) and Al2O3 (14.02 wt%) are the major components of the clay. TG-DSC shows that the mineral contains 15.55% moisture. IR transmittance spectrum shows the common vibration bands present in the sample which include O–H stretching of inter-porous water, symmetric and asymmetric stretching of hydroxyl functional groups, asymmetrical stretching of internal tetrahedra (O–Si–O and O–Al–O), symmetrical stretching of external linkages, and so on. The measured CEC were found to be 91.37 and 43.01 meq/100 g according to the ammonium acetate method and barium acetate method, respectively.

Calcination Effect on Structural Trasformation of Barium Titanite Ferroelectric Ceramic by Sol-Gel Method

High purity barium titanate BaTiO3 was successfully synthesized by using the sol-gel technique. Barium acetate Ba(CH3COO)2 and tetrabutyl titanate, Ti(C4H9O)4 was dissolved moderately in the solvent of glacial acetic acid and ethanol was added as the chemical modifier. The synthesized BaTiO3 nanoparticle was calcined at the temperature range of 700 ºC to 1100 ºC. The powders were further characterized by X-ray diffraction and scanning electron microscopy (SEM). Fined BaTiO3 powders result indicates the phase of tetragonal structures and high crystallites of BaTiO3. It was observed that the crystallinity and particle size of BaTiO3 is greatly influenced by the calcination temperature.

Yb-Doped BaCeO3 and Its Composite Electrolyte for Intermediate-Temperature Solid Oxide Fuel Cells

BaCe0.9Yb0.1O3−α was prepared via the sol-gel method using zirconium nitrate, ytterbium trioxide, cerium nitrate and barium acetate as raw materials. Subsequently, it reacted with the binary NaCl~KCl salt to obtain BaCe0.9Yb0.1O3−α-NaCl~KCl composite electrolyte. The structure, morphology, conductivity and fuel cell performance of the obtained samples were investigated. Scanning electron microscope (SEM) images showed that BaCe0.9Yb0.1O3−α and NaCl~KCl combined with each other to form a homogeneous 3-D reticulated structure. The highest power density and conductivity of BaCe0.9Yb0.1O3−α-NaCl~KCl was 393 mW·cm−2 and 3.0 × 10−1 S·cm−1 at 700 °C, respectively.

Barium acetate as an additive for high performance perovskite solar cells

Defects within the halide perovskite films limit the efficiency and stability of perovskite solar cells (PSCs).

Synthesis and characterization of nanocrystalline barium strontium titanate powder by a modified sol-gel processing

In this research work, nanocrystalline BST (Ba0.6Sr0.4TiO3) powders were synthesized through a modified sol-gel process, using barium acetate, strontium acetate and titanium isopropoxide as the precursors. In this process, stoichiometric proportions of barium acetate and strontium acetate were dissolved in acetic acid and titanium (IV) isopropoxide was added to form BST gel. The as-formed gel was dried at 200 °C and then calcined in the temperature range of 600 to 850 °C for crystallization. The samples were characterized by infrared spectroscopy method (FT-IR), X-ray diffraction technique (XRD) and field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectroscopy. EDS analysis of these samples confirmed the formation of the final phase with the special stoichiometry. The formation of a cubic perovskite crystalline phase with nanoscale dimension was detected using the mentioned techniques. The results showed that the obtained crystallite sizes were 33 and 37 nm for BST powder calcined at 750 and 850 °C, respectively.