The extent of metal retained by the support is a function of the interaction between
precursor and support. One way strong interaction can be created is via the electrostatic
adsorption mechanism [5]. If the metal solution is adjusted before contact, for example
by adding acid or base so as to promote metal sorption onto the support, the concept of
“strong electrostatic adsorption (SEA) method” can be introduced, because in this case
the interaction between the metal complex and the support is strong electrostatic
adsorption.