Effects of muscovite matrix on photocatalytic degradation in TiO2/muscovite nanocomposites

Abstract

A series of TiO2/muscovite nanocomposites was prepared by liquid precipitation method followed by thermal treatment at different temperatures. Thermal analysis, X-ray diffraction and solid ultraviolet diffuse reflection spectroscopy were employed to analyze the effects of muscovite matrix on the crystal phase, grain size and light absorption properties of the supported TiO2 nanoparticles. The effect of muscovite matrix on the photocatalytic performance of the nanocomposites was identified by trapping experiments using rhodamine B (RhB) as target degradant. The results indicated that the muscovite matrix had a retarding effect on the growth and phase transformation of TiO2 in the nanocomposites. The photocatalytic efficiency of samples decreased with increase in temperature of the thermal treatment. The photocatalytic efficiency of the sample prepared at 400 °C was the highest, with the degradation rate of 97% for RhB. The photocatalytic degradation of RhB by the nanocomposite catalyst followed pseudo-first-order reaction kinetics. The main reactive species in the degradation process were O2−, h+ and ·OH in order of participation. The muscovite matrix loading promoted h+ to oxidize H2O to form ·OH, which also helped improve the efficiency of catalytic degradation of pollutants.