Preparation of Ag@AgCl/NaNbO3 Composite and Its Application in Catalysis for Dye Decoloration

Abstract

An efficient and stable visible-light-driven photocatalyst Ag@AgCl/NaNbO3 composite was prepared and applied for decoloration of dye. The Ag@AgCl/NaNbO3 composite was synthesized via depositing Ag@AgCl nanoparticles on the surface of NaNbO3. The decoloration of MB was evaluated to reflect the catalytic activity of Ag@AgCl/NaNbO3 composite. The results revealed that the Ag@AgCl/NaNbO3 composite prepared in this study exhibited much higher visible-light photocatalytic activity for degradation of MB aqueous solution than that of pure NaNbO3. The degradation efficiency of MB was 87.5% for Ag@AgCl/NaNbO3 composite prepared from 1.5 M AgCl, after 2 h exposure to visible-light irradiation. The Ag@AgCl/NaNbO3 composite still maintained a high photocatalytic activity even after 5 repeated runs. The possible transfer routes of the photoexcited electrons and holes were investigated to explain the photocatalytic activity based on conduction band and valence band potentials of NaNbO3. The photoexcited electrons on the surface of the Ag nanoparticles transferred into the conduction band of NaNbO3 and Ag nanoparticles. The injected electrons also transferred to the ubiquitously present molecular oxygen to form active species O–2, ·HOO, H2O2 and ·OH, which enhanced the degradation and mineralization of MB.