Characteristics of Nano-Size LaCrO3 Prepared Through Sol-Gel Route Using Pectin as Emulsifying Agent

Abstract

In this study, nano-size LaCrO 3 was prepared through sol-gel route using pectin as emulsifying agent, followed by freeze -drying to obtain solid sample. The sample was prepared by mixing the solution of La(NO 3 ) 3 .6 H 2 O and Cr(NO 3 ) 3 .9 H 2 O with pectin solution under magnetic stirring. The sample was frozen and subsequently subjected to freeze -drying and calcination treatment at temperatures of 600, 700 and 800 ºC for 6 h. The calcined samples were characterized with several techniques. The phase composition was evaluated using the X-ray diffraction (XRD) technique, followed by crystallite size calculation using Scherrer Methods. The functionality of sample was identified using Fourier transform infrared (FTIR) spectroscopy, surface structure in three dimensional images was analyzed using Transmission electron microscopy (TEM), and particle size distribution was determined by Particles Size Distribution (PSA). The results of XRD characterization indicated that materials consist of various crystalline phases, with LaCrO 3 as a major phase. FTIR Analysis revealed the existence of both Lewis and BrØnsted -Lowry acid sites, with Lewis acid as the prominent sites, represented by the absorption band located at around 1636 cm -1 . The samples were found to display relatively homogeneous surface morphology, having the crystallite size in the range of 24 to 25 nm according to Scherrer equation. The PSA analyses revealed increased relative percentages of nano-size portion in the sample from 22 to 89% as temperatures increased from 600 to 800 ºC, with the particle size in the range of 30 to 35 nm as seen by the TEM .

Pectins as Emulsifying Agent on the Preparation, Characterization, and Photocatalysis of Nano-LaCrO3

“…From Figure 6, it can be implied that there are two or three regions of the particle size which are quantum dot, nano-, and micron sizes. Overall, it can be said that nanosize of the particles 21.9, 86.4, and 89.11% referred to LaCrO 3 calcined at 600, 700, and 800°C, respectively [49].…”

“…The preparation was conducted by dissolving specified mass of La(NO 3 ) 3 .9H 2 O and Cr(NO 3 ) 3 .6H 2 O, respectively, in 100 mL of pectin solution (4 g pectin). The overall procedure was described in the previous article [49].…”

“…X-ray diffraction experiments are carried out by the procedure as described in the previous article [49]. To know the crystallite size, the representative peak of a diffractogram can be elucidated by using the Scherrer method of calculation [51].…”

“…In principle, FTIR analysis in the material field is used to assess the functional groups and what bonds are formed in the material prepared in relation to the expected compound. In preparing samples for their analysis, the procedures performed are standard and can be referenced in various libraries [49,59,60].…”

“…The results also reflect that the existence of Brønsted-Lowry and Lewis acid sites is indicated by the presence of absorption bands at wave number 1400 and 1630 cm −1 , respectively. In detail, the acidity characteristics of the LaCrO 3 calcined at the various temperatures were described in the previous article [49].…”