Co, Al co-doped zinc oxide [Zn1-x-yCoxAlyO; x = 0.04, 0.03, 0.02; y = 0.01, 0.02, 0.03] nanoparticles were synthesized by a citrate assisted combustion method at 500 οC for various doping levels using zinc, cobalt and aluminum nitrates as precursors. The synthesized oxide nanopowders of different compositions were calcined at 600, 700 and 800 οC for 2 h. The synthesized Zn1- x-yCoxAlyO nanocrystals were characterized for their thermal, structural, and morphological features. The structural studies resulting in doping-independent crystallite sizes and the thermal analysis confirm the execution of complete combustion. The average particle size of ZnO nanocrystals decreases due to the tension caused by Co and Al dopants in the zincite structure and the ionic size differences. The as-prepared nanoparticles with an average particle size in the range of 10-20 and 20-30 nm were observed for doped and undoped ZnO, respectively.

Keywords: Combustion synthesis, ZnO, Nanoparticles, Co-dopants.