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

Ti 3 C 2 -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, CeO 2 /Ti 3 C 2 -MXene hybrids were prepared by the in-situ growth of cube-like CeO 2 using ultrathin Ti 3 C 2 -MXene nanosheets as a two-dimensional platform via a simple hydrothermal route. Upon exposure to solar light, the CeO 2 /Ti 3 C 2 -MXene hybrid with the optimal ratio of Ti 3 C 2 -MXene exhibited enhanced performance in photocatalytic tetracycline degradation and CO 2 reduction, with activities 6.3 and 1.5 times greater than those of pristine CeO 2 , respectively. The improved activity of CeO 2 /Ti 3 C 2 -MXene was attributed to the Schottky junction induced by the built-in electric field between CeO 2 and Ti 3 C 2 -MXene, which drives the photogenerated electrons from CeO 2 to Ti 3 C 2 -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 Ti 3 C 2 -MXene as co-catalysts for building efficient photocatalytic systems enacted in pollutant degradation and energy conversion.