Synthesis, characterization and photocatalytic property of nanostructured Al-doped ZnO powders prepared by spray pyrolysis

In this research, we have synthesized Al-doped ZnO (AZO) nanostructured powders via a spray pyrolysis technique. Aerosol droplets of the mixture of the zinc and aluminum nitrates with concentration varied from 0.06 to 3.0M were pyrolyzed in air at temperatures ranging from 500 to 800 degrees C. The produced AZO powders had a primary and a secondary particle sizes in the range of 15-30 nm and 1-3 mu m, respectively. We found that the primary particle sizes increased with the reaction temperature and precursor concentration. In addition, the relative density of the particles was found to increase with reaction temperature but decrease with precursor concentration. Particles synthesized from high precursor concentration tend to form hollow and/or porous structure, which result in better photocatalytic ability due to higher specific surface area. (c) 2006 Elsevier B.V. All rights reserved.