Effect of urea on the synthesis of Al-doped ZnO nanoparticle and its adsorptive properties for organic pollutants

Abstract Al-doped ZnO nanoparticles were synthesized through a solution combustion synthesis derived from zinc nitrate, aluminum nitrate and urea mixed solution. The effects of fuel/oxidizer molar ratio ( ϕ ) on the morphology, physical properties, and adsorptive properties for organic pollutants of Al-doped ZnO have been systematically investigated. The results indicated that the homogeneous Al-doped ZnO powders might be prepared by selecting an optimum ϕ in solution. The results of XRD pointed toward a significant pure wurtzite ZnO phase for 2 mol% Al-doped ZnO powders prepared with different ϕ . With the increase of ϕ , the morphology of the products changes from clusters of irregular particles into flakes. A well-distributed and smaller crystallite size varying from 30 nm to 50 nm was observed from 2 mol% Al-doped ZnO sample ( ϕ = 4). In addition, the Al-doped ZnO sample ( ϕ = 4) showed a higher absorption ability and shorter equilibration time for organic pollutants compared to other samples.