Comparison of adsorptive features between silver ion and silver nanoparticles on nanoporous materials

The removal of Ag+ or AgNPs released from nano-products or effluent of WTP is important to reduce the potential risk of AgNPs. In this work, we prepared bimodal nanoporous silica (BNS) to compare the removal efficiency of Ag+ and AgNP with unimodal nanoporous silica (NS). To determine the adsorption capacity of Ag+ and AgNPs on NS and BNS, isotherm and kinetics studies was carried out at different concentrations. The results showed BNS with a bimodal nanoporous structure and a large external surface showed a higher uptake capacity and faster adsorption rate.