Preparation of In(OH)3 Nanorods and Nanocubes and the Effect on In2O3 Particle Size in the Microreactor

Abstract

Indium hydroxide (In(OH)3) nanorods and nanocubes were prepared with a precipitation process using a membrane dispersion micromixer. Indium oxide (In2O3) particles with various sizes were subsequently prepared by calcination of the In(OH)3 particles. A microreactor was used for its improved mixing performance to obtain In(OH)3 particles with a higher degree of crystallinity and In2O3 particles with controllable sizes. The effect of pH, using ammonia as the alkali source, on the In(OH)3 particle shape and In2O3 particle size with the alkali source of ammonia was investigated. In(OH)3 nanorods were synthesized at pH = 9.0, whereas at pH = 7.0, In(OH)3 nanorods and nanocubes were formed. It was observed that, during the calcination process, the In(OH)3 nanorods transformed into In2O3 particles with a size of 20–30 nm, while the In(OH)3 nanocubes transformed into In2O3 particles with a size of 60–70 nm. It was demonstrated through changing the alkali source that the concentrations of NH4+ and NH3 had a great ...