One-pot synthesis of La2O3-decorated Mg-Al oxides nanosheets for solar-light driven photocatalytic activity

Abstract

La2O3-decorated Mg-Al layered double oxides (La2O3/Mg-Al) nanosheets were prepared by a one-pot hydrothermal route for the visible light induced photo-degradation of methylene blue (MB). La2O3 is favorable for enhancing the adsorption-photocatalytic activity of Mg-Al oxides. Effects of La2O3 content, pH values, and inorganic ions on the removal efficiency and photocatalytic kinetics of MB were well discussed. The optimal 3-La2O3/Mg-Al with a La2O3 content of 4.32 % presents the best adsorption-photocatalysis capacity and stability for MB in visible light region. The removal efficiency of MB is 98.06 % within 100 min, and the corresponding photocatalysis kinetic constant of 3-La2O3/Mg-Al is 0.051 min−1. The combined effect of La2O3 and Mg-Al oxides and the oxygen vacancies are likely to enhance the charge transfer and the separation of charge carriers. OH and O2− radicals are vital for the photocatalytic activity of 3-La2O3/Mg-Al under visible light irradiation.