Enhanced Photocatalytic Degradation of Methyl Orange Using Nitrogen-Functionalized MesoporousTiO2 Decorated with Au9 Nanoclusters

Abstract

A novel catalyst for dye degradation is fabricated through attaching Au9 nanoclusters (Au9 NCs) to N functionalized mesoporous TiO2 (NMTiO2). The NMTiO2 is created through chitosan-assisted soft templating resulting in an N terminated surface preventing the agglomeration of the Au9 NCs adsorbed surface and enhancing the overall loading with Au9. The calcination atmosphere influenced the surface properties of the NMTiO2 and its capability to adsorb the Au9 NCs. The photocatalytic effectiveness of these materials was probed through methyl orange (MO) dye degradation. The black coloured Au9/NMTiO2 catalyst is highly effective to completely degrade MO dyes within 20 min due to its large reaction constant (0.176 min−1). Parameter interactions for the dye degradation process were explored using response surface methodology (RSM) and the dependency of MO degradation on the affecting parameters was evaluated based on the statistical analysis and 3D plots.