Preparation and adsorption behavior of amino-functionalized bridged organosilicas for the removal of Ag(I) from aqueous solutions

Novel p-phenylenediamine-bridged organosilica (PPDA-BOS-T) materials were synthesized via the co-condensation reaction assisted by tetraethyl orthosilicate (TEOS). These amino-functionalized organosilicas were characterized by Fourier transform infrared spectrometer, N-2 sorption, scanning electron microscopy, and transmission electron microscopy. The addition of TEOS played a positive role in the construction of the porous network structure of the bridged organosilicas. The saturation adsorption capacity for Ag(I) of the PPDA-BOS-T could reach 82.88 mg g(-1). The conformity to the Freundlich model indicated multilayer adsorption with active sites. Furthermore, the adsorption was followed well by the pseudo-second-order model, and the intraparticle diffusion was proved to be the rate-limiting step during the adsorption of Ag(I). Finally, the thermodynamic parameters including the change of free energy (Delta G), enthalpy (Delta H), and entropy (Delta S) of adsorption were calculated.

Automated summary

Novel amino-functionalized organosilica materials were synthesized through co-condensation assisted by tetraethyl orthosilicate. The addition of TEOS was beneficial for constructing a porous network structure in the bridged organosilicas. These materials showed high saturation adsorption capacity for Ag(I) and followed the Freundlich model and pseudo-second-order model, with intraparticle diffusion identified as the rate-limiting step. Thermodynamic parameters, including ΔG, ΔH, and ΔS, were calculated for the adsorption process.