Built-in electric field induced CeO2/Ti3C2-MXene Schottky-junction for coupled photocatalytic tetracycline degradation and CO2 reduction

Ti3C2-MXene, which exhibits excellent electronic conductivity and optical properties, has been identified as a promising noble-metal-free co-catalyst for the development of efficient photocatalysts for environmental remediation. Herein, CeO2/Ti3C2-MXene hybrids were prepared by the in-situ growth of cube-like CeO2 using ultrathin Ti3C2-MXene nanosheets as a two-dimensional platform via a simple hydrothermal route. Upon exposure to solar light, the CeO2/Ti3C2-MXene hybrid with the optimal ratio of Ti3C2-MXene exhibited enhanced performance in photocatalytic tetracycline degradation and CO2 reduction, with activities 6.3 and 1.5 times greater than those of pristine CeO2, respectively. The improved activity of CeO2/Ti3C2-MXene was attributed to the Schottky junction induced by the built-in electric field between CeO2 and Ti3C2-MXene, which drives the photogenerated electrons from CeO2 to Ti3C2-MXene and expedites the segregation of the electrons and holes. This work may shed light on the careful design of novel Schottky junctions utilizing noble-metal free Ti3C2-MXene as co-catalysts for building efficient photocatalytic systems enacted in pollutant degradation and energy conversion.