Application of natural organic matter in the biosynthesis of α-alumina nanoparticles: The humic sol-gel route

Abstract

A new low-cost, low environmental impact methodology has been developed for the synthesis of nanostructured α-alumina. The proposed route employs the complexation capacity of natural organic matter (NOM). The parameters time, calcination temperature, mass, and initial pH were evaluated in order to develop a procedure that was simple, efficient, and had a low energy requirement. The α-alumina phase was produced after 4 h at pH 4.0 and a temperature of 1,000°C. This temperature was at least 200°C lower than those used previously for synthesis of alumina. Microscope images revealed the formation of structures with hollow spherical morphology. The results of EDS analyses showed that spurious phases were absent, in agreement with XRD measurements.