Effect of preparation method, loading of Co3O4 and calcination temperature on the physicochemical and catalytic properties of Co3O4/ZnO nanomaterials

•ZnO catalysts prepared by thermal decomposition, sol-gel and precipitation methods.•Co3O4/ZnO catalysts prepared by impregnation method using different zinc precursors.•The SBET of Co3O4/ZnO catalysts were much higher than those of the pure oxides.•The decomposition of H2O2 of Co3O4/ZnO catalysts is higher than of the pure oxides.•The addition of Co3O4 to ZnO catalyst modified the morphology.

ZnO nanomaterials (ZnOT, ZnOS and ZnOP) were successfully synthesized by thermal decomposition, sol-gel auto combustion and precipitation methods, respectively. Co3O4/ZnO catalysts were synthesized by impregnation method, nominated as CoZnOT, CoZnOS and CoZnOP, respectively. The as-prepared catalysts were characterized by XRD, N2 adsorption-desorption isotherms, HR-TEM and FT-IR techniques. The SBET of CoZnO nanomaterials were significantly higher than those of the pure oxides. Further, the Co3O4/ZnO sample in which ZnO synthesized via sol-gel combustion using citric acid (CoZnOSCI) showed the largest surface area while CoZnOP sample showed the smallest value. The HR-TEM images showed that addition of Co3O4 to ZnO catalyst and the calcination temperature affected the morphology. The catalytic decomposition of H2O2 of the Co3O4/ZnO catalysts is higher than that of the pure oxides. The most catalytically active sample is Co3O4/ZnO in which ZnO synthesized via thermal decomposition of zinc carbonate (CoZnOTC) while CoZnOSCI catalyst being the less active one.

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