Preparation and characterization of nanostructured barium oxide

Abstract

It was found that the basic catalytic property of the metal oxide was increase with high surface area and nanosized particles. In this study, surface modified Barium oxide (BaO) was synthesized by hydration-dehydration method. Barium hydroxide ( Ba(OH)2) has prepared from Barium Peroxide (BaO2) which acted as precursor. The Ba(OH)2 was calcined at a temperature of 50°C to 300°C under vacuum atmosphere of 10-3 mbar. Prepared samples were characterized using thermogravimetric-derivative thermogravimetry (TG-DTG), fourier-transform infrared (FTIR), X-ray powder diffraction (XRD), single point Brunauer-Emmet Teller (BET) surface area analysis and field emission scanning electron microscope (FESEM). The TG-DTG result shows that the major weight lost occurs at a temperature 110°C to 150°C which was 0.7%. This indicated the decomposition of barium hydroxide to barium oxide. The XRD diffractogram of BaO proved that Ba(OH)2 has been transformed to BaO in tetragonal formed as the temperature increases. The particle size for the surface modified barium oxide was calculated using Scherer’s equation and the resulting particle size was approximately 34 nm. Thus, the prepared surface modified BaO with nano size particles have been produced in this study. The amount of basic sites was investigated using the most fundamental chemical techniques of back titration and as the temperature increases from 150°C to 300°C, the basic sites increases from 0.67 to 1.67 mmol g-1 respectively. This is most probably due to the formation of more BaO with basic sites that occur during the activation process at temperature 300°C. The chemical properties of the prepared surface modified BaO were measured using electron spin resonance (ESR) method. Based on ESR study, a single peak g-value at 1.9830 was observed throughout the 30 minutes UV radiation and shown that only one site which active in electron trapping sites.