Dry milling followed by ultrasonic irradiation in the presence of small amounts of aqueous NaOH, was used to synthesise ZnAl-layered double hydroxide （LDH）. The synthetic conditions were optimised and the Zn（OH）2,...Dry milling followed by ultrasonic irradiation in the presence of small amounts of aqueous NaOH, was used to synthesise ZnAl-layered double hydroxide （LDH）. The synthetic conditions were optimised and the Zn（OH）2, ZnO, and AI（OH）3 contaminants were removed by rinsing with aqueous NH3 solution from the sample prepared in the optimum conditions. Thus, phase-pure ZnAl-layered double hydroxide was obtained with high crystallinity. All materials produced during the syntheses were characterised by X- ray diffractometry, and a rose-like morphology was observed by scanning electron microscopy in the phase-pure sample. By changing the initial Zn/Al ratio, it was revealed that an LDH with low zinc content was always formed, probably through substitution of some of the Zn2. ions by AI3. ions in the gibbsite lattice.展开更多
文摘Dry milling followed by ultrasonic irradiation in the presence of small amounts of aqueous NaOH, was used to synthesise ZnAl-layered double hydroxide （LDH）. The synthetic conditions were optimised and the Zn（OH）2, ZnO, and AI（OH）3 contaminants were removed by rinsing with aqueous NH3 solution from the sample prepared in the optimum conditions. Thus, phase-pure ZnAl-layered double hydroxide was obtained with high crystallinity. All materials produced during the syntheses were characterised by X- ray diffractometry, and a rose-like morphology was observed by scanning electron microscopy in the phase-pure sample. By changing the initial Zn/Al ratio, it was revealed that an LDH with low zinc content was always formed, probably through substitution of some of the Zn2. ions by AI3. ions in the gibbsite lattice.
