this is clearly an interesting and important technical question. Layered double hydroxides can be prepared either by hydrothermal syntheses or sol-gel methods. Sol-gel syntheses normally start with simple organic salts or metal alkoxdes. For a good overview about this topic please have a look at the following very useful review article which will certainly help you in your analysis:
Layered double hydroxides (LDHs): versatile and powerful hosts for different applications
The following relevant paper is even freely available as public full text on RG:
Layered Double Hydroxides
Research Layered Double Hydroxides
As you can see, it always pays off to search the "Publications" section of RG first. Numerous helpful ppapers have been posted here by RG members, many of them even as public full texts.
Thanks @Frank T. Edelmann for your comments. They all discuss the general idea about sol-gel synthesis not the detail stpes to follow while doing the practical experiments specifically when using INORGANIC SALTS as precursor.
many thanks for your kind response. There are also various publications available which describe in detail the sol-gel synthesis starting from simple inorganic salts such as the metal nitrates. As a typical example please have a look at the following potentially useful article:
Sonication accelerated formation of Mg-Al-phosphate layered double hydroxide via sol-gel prepared mixed metal oxides
Here the authors use magnesium and aluminum nitrates as precursors.This article has been published Open Access (see attached pdf file). In order to suggest to you more suitable literature references it would be helpful if you could specify in more detail which metals you are interested in.
Dear Ararso Nagari Wagassa many thanks for the additional information. For a straightforward synthetic method to prepare Ni-Al LDH by co-precipitation using simple nitrate salts as precursors please check the following article which is freely available as public full text on RG:
Synthesis and Characterization of Ni/Al-LDH nano hybrid with (Ascorbic acid) and Kinetic Controlled Release Study of (Ascorbic acid) From Ni/Al-LDH
Article Synthesis and Characterization of Ni/Al-LDH nano hybrid with...
Also search the "Publications" section of RG for terms like "Ni-Al LDH sol-gel" etc. Various other relevant papers about this topic have been posted by RG members. You might also consider the use of the acetylacetonate complexes of nickel and aluminum. Both are very easy to make, and they are good precursors for the sol-gel synthesis of N-Al LDHs.