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ZnO nanosheets and nanoflakes were grown on alumina particles in the absence of surfactants via heterogeneous precipitation using urea,zinc acetate and bayerite as precursors.Thermo-gravimetric analysis(TGA),X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FTIR) were used and the results indicated the formation of only two phases: wurtzite-type ZnO and g-Al2O3.ZnO nanoflakes were grown on alumina particles in the samples with ZnO content of 40 and 60 wt%.By increasing the ZnO content to80 wt%,a porous hierarchical structure of ZnO with nanosheet arrays appeared.Both of these nanoflakes and nanosheets were about 40e80 nm in thickness and about 1e2 mm in diameter.It was proposed that Zn5(CO3)2(OH)6nuclei undergo higher growth rates in thin sheets at edges of bayerite particles with a higher surface energy.The BrunauereEmmetteTeller(BET) measurements proved a reachable high surface area for hierarchical structures of ZnO nanosheets,which could mainly be attributed to their unique growth on alumina particles.Also,UV absorption results revealed that ZnOeAl2O3compositions still show the UV characteristic absorption of ZnO,which can evidence the presence of photocatalytic properties in ZnOeAl2O3compositions.
ZnO nanosheets and nanoflakes were grown on alumina particles in the absence of surfactants via heterogeneous precipitation using urea, zinc acetate and bayerite as precursors. Thermo-gravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used and the results indicated the formation of only two phases: wurtzite-type ZnO and g-Al2O3.ZnO nanoflakes were grown on alumina particles in the samples with ZnO content of 40 and 60 wt% .By increasing the ZnO content to 80 wt% , a porous hierarchical structure of ZnO with nanosheet arrays. Both of these nanoflakes and nanosheets were about 40e80 nm in thickness and about 1e2 mm in diameter. It was proposed that Zn5 (CO3) 2 (OH) 6 nuclei undergo higher growth rates in thin sheets at edges of bayerite particles with a higher surface energy. The Brunauere Emmette Teller (BET) measurements proved a reachable high surface area for hierarchical structures of ZnO nanosheets, which could mainly be attributed to the ir unique growth on alumina particles. Also, UV absorption results revealed that ZnOeAl2O3compositions still show the UV characteristic absorption of ZnO, which can evidence the presence of photocatalytic properties in ZnOeAl2O3compositions.