Ultrafast removal of arsenic using solid solution of aero-gel based Ce_1-XTi_xO_2-Y oxide nanoparticles

An aero-gel based solid solution of titanium and cerium oxide nanoparticles have been used for the first time for ultra fast and trace level removal of arsenic from water. The interconnected long range ordered mesoporous structure was observed from TEM analysis which has been verified as an essential facet for the fast removal of arsenic in this study. The HR-XRD spectra indicated the face centred cubic structure with Fm3¯m space group. Le-Bail refinement and Raman spectroscopy confirmed the formation of single phase solid solution of Ce_1-XTi_xO_2-Y oxide nanoparticles. The HR-XPS and FT-IR study indicated the surface complexation and partial oxidation of As(III) to As(V) via electron transfer mechanism by reduction of Ce(IV) to Ce(III) and Ti(IV) to Ti(III) simultaneously during adsorption process. The kinetics study demonstrated 99% removal of As(III) within 10 min of initiating the adsorption process. The effect of pH and interfering ions confirmed the wide range of applicability for solid solution of titania and cerium oxide nanoparticles over the different environmental conditions for the removal of arsenic. The adsorption capacity for our best adsorbent (Ce_0.8Ti_0.2O_2-y) was found to be 2 × 10⁵ mg kg^-1 while the lowest concentration of water body system was 7 μg L^-1 which is the minimum concentration of arsenic achieved by any metal oxide based adsorbent.