Modifying the surface of TEOS xerogel by metal ion Zn(II)

The removal of 2,4-dichlorophenol from aqueous solution by modified TEOS xerogel has been studied in batch experiments at varying pH (2.0–8.0). Tetraethyl orthosilicate (TEOS) xerogel recently has been considered as an adsorbent which is more active. Surface of the adsorbent due to the outward oxygen atoms in the molecular structure, is negatively charged, so this solid, shows good ability to adsorb metal ions. But because of the negative charge on the surface of the adsorbent, the anions, particularly organic anion compounds are not absorbed. To fix this problem, it can set the metal ions on the surface of the solid. By placing Zn ions on the xerogel, a positive charge on the surface of the adsorbent is made, which increases the ability of the adsorbent to attract 2, 4-dichlorophenol from aqueous solutions. Results show an increase in the adsorption by about 17% on empty xerogel, by about 60% in xerogel modified with metal Zn (II) ion.