Effect of crystallite size and calcination temperature on the thermal stability of single nanocrystalline chromium oxide: expressed by novel correlation

Abstract

The thermal reaction of chromium acetylacetonate in various organic solvents at 300 °C for 2 h yielded an amorphous product. Single nanocrystalline chromium oxide was obtained after being calcined at 300 °C for 1 h. The crystallite size of product is in the range of 16–26 nm. In this work, the thermal stability of product was given by BET/BET₀. It was found that the crystals of large crystallite size show higher thermal stability than the crystals of small crystallite size. Thermal stability of chromium oxide can be presented by the correlation of the BET surface area after calcination, crystallite size of as-synthesized product and calcination temperature (500–900 °C) as shown below.

where

BET = surface area of product after calcination (m²/g)

BET₀ = surface area of as-synthesized product (m²/g)

T = calcination temperature (K)

d₀ = crystallite size of as-synthesized product (nm)

n = arbitrary constant

Keywords:

• Thermal stability
• Single crystal
• Chromium oxide
• Solvothermal method