The pH effects on the formation of Ni/Al nitrate form layered double hydroxides (LDHs) by chemical precipitation and hydrothermal method

Abstract

The Ni/Al nitrate form layered double hydroxides (LDHs) were successfully synthesized by chemical precipitation and hydrothermal methods through pH control, the pH effects on the formation of which was studied. It was found that at low pH value, nitrate hydrotalcite was obtained, while at high pH value, carbonate hydrotalcite was produced. Ni/Al nitrate form LDHs particles with good crystallinity and classical hexagonal shape were obtained by hydrothermal treatment and characterized by the scanning electron microscopy (SEM). The transformation mechanism of the Ni/Al LDHs between nitrate and carbonate form under pH control was also discussed.