The production and increasing use of silver nanoparticles (AgNPs) obviously results in their release into the environment, leading to a risk to the environment due to their toxic effects. Thus, the removal of AgNPs from water is highly needed. Here, we demonstrate that nitrogen rich (similar to 10% nitrogen content) core-shell magnetic mesoporous silica is a promising adsorbent for the removal of AgNPs. For this, the poly(ethylenimine) functionalized core-shell magnetic mesoporous silica composites (Fe3O4@SiO2-PEI) were prepared, and characterized by TEM, FT-IR, XRD, TG and N-2 adsorption-desorption. The removal of AgNPs by Fe3O4@SiO2-PEI as a function of contact time, concentration of AgNPs, solution pH and ionic strength were studied. The adsorption kinetic data could be described by the pseudo-second-order rate model. Both Langmuir and Freundlich models fitted the adsorption data well. The adsorption capacity for AgNPs is 909.1 mg/g, which is 5-181 times higher than that of the previously reported adsorbents for AgNPs. Interestingly, the silver adsorbed onto Fe3O4@SiO2-PEI exhibits highly catalytic activity for 4-nitropheol (4-NP) reduction with a rate constant of 0.072 min(-1), which is much higher than those by other AgNPs reported before. The silver-loaded Fe3O4@SiO2-PEI promises good recyclability for at least five cycles, showing great potential in practical applications. (C) 2017 Elsevier B.V. All rights reserved.