TiO2 incorporated in magnetic mesoporous SBA-15 by a facile inner-pore hydrolysis process toward enhanced adsorption photocatalysis performances for As(III)

摘要

A facile inner-pore hydrolysis combining solvent evaporation method was used to decorate mesoporous silica, in which gamma-Fe2O3 nanoparticles was preloaded onto mesoporous SBA-15 followed by decoration of TiO2 nanoparticles. This decoration process exploited the homogeneous dispersivity of gamma-Fe2O3 and TiO2 nanoparticles in/on SBA-15 and inhibit aggregation of gamma-Fe2O3 and TiO2 nanoparticles, which in turn leaded to a synergistic photocatalytic oxidation and adsorption of As(III). It was found that the prepared nanocomposites had mesoporous structure, large specific surface area, high pore volume and superparamagetism according to SEM/TEM. N-2 adsorption-desorption isotherms, XRD and VSM analysis. Experimental results show that SBA-15/gamma-Fe2O3-TiO2 can oxidize As(III) to As(V) efficiently in the photocatalysis reaction. At the same time, As(V) is effectively removed through adsorption by the composites. In addition, with the treatment of alkali solution, As(V) can be easily desorbed from SBA-15/gamma-Fe2O3-TiO2. After reusage for 5 times, the composites still retain comparable catalysis and adsorption performance compared with that of first use, revealing the excellent stability of the composites. (C) 2015 Elsevier Inc. All rights reserved.