Amine-functionalized nanosilica-supported Dawson heteropolyacid: an eco-friendly and reusable photocatalyst for photodegradation of malachite green

Dawson heteropolyacid, H 6 [P 2 W 18 O62 ], was chemically anchored to the amine-functionalized nanosili- ca surface in different loadings. The synthesized nano- composite was characterized by FT-IR spectroscopy and N 2 adsorption experiments. The preservation of the struc- ture of the Dawson and dispersion of the cluster on the support were verified on the basis of the spectroscopic data. The photocatalytic degradation efficiency of the synthe- sized nanocomposites was studied using an aqueous solu- tion of malachite green dye as a model water pollutant. The mineralization of dye contents was investigated in different loadings from 10 to 30 % at room temperature. Decolor- ization was observed in shorter time using 30 % loading. The photocatalyst was reusable after the filtration and remained active even after being washed with hot water, which confirm its attachment firmly to the surface of amine-functionalized nanosilica.