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

•Al-doped ZnO nanoparticles were synthesized through a solution combustion synthesis.•The fuel/oxidizer molar ratio affects the crystallite size of Al-doped ZnO.•The fuel/oxidizer molar ratio affects the adsorption properties of Al-doped ZnO.

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 (ϕϕ) 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 ϕϕ in solution. The results of XRD pointed toward a significant pure wurtzite ZnO phase for 2 mol% Al-doped ZnO powders prepared with different ϕϕ. With the increase of ϕϕ, 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 (ϕϕ = 4). In addition, the Al-doped ZnO sample (ϕϕ = 4) showed a higher absorption ability and shorter equilibration time for organic pollutants compared to other samples.

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