Sonochemical synthesis of CeO2 nanoparticles with high photocatalytic and antibacterial activities under visible light

Abstract

AbstractCerium oxide (CeO2), one of the most significant heterogeneous catalysts, has attracted extensive research interest. Herein, ultrafine spherical CeO2 with a diameter of 5 nm is successfully synthesized within a reaction time of 25 min by a simple and environmentally friendly sonochemical method without any additional oxidants or high temperature and pressure conditions, and 50 nm spherical CeO2 was obtained by heat treating the 5 nm spherical CeO2 in 400°C air atmosphere condition for 3 h. By controlling the ultrasonic condition, a specific surface area of up to 194.2 m2/g and a bandgap as low as 2.2 eV are achieved in the CeO2 nanoparticles without any heat treatment. Further study has shown that the as‐prepared spherical CeO2 without heat treatment exhibits remarkable photocatalytic and antibacterial activities under visible light conditions. The study is beneficial for energy conservation in fabricating ultrafine photocatalytic and antibacterial nanomaterials.