Regulation of a rutile/anatase TiO2 heterophase junction in situ grown on Ti3C2Tx MXenes with remarkable photocatalytic properties

TiO2(rutile-anatase, R-A)/Ti3C2Tx heterophase junction (HPJ)-Schottky junction (SHJ) composites oxidized in situ by Ti3C2Tx MXenes were synthesized via a one-step hydrothermal method using Ti3C2Tx MXenes as the Ti source and water as the solvent. There was no need for the induction and oxidation of other chemical reagents in the reaction, the reaction conditions were green and non-toxic, and the experimental operation was simple. The number of TiO2(R-A) HPJs and Ti3C2Tx SHJs can be regulated by changing the reaction temperature and time. The optimized photocatalyst exhibited a large number of TiO2(R-A) HPJs attached to the surface of Ti3C2Tx. TiO2(R-A)/Ti3C2Tx-200 degrees C-15 h showed a photocatalytic N-2 reduction efficiency of 59.35 mu mol L-1 h(-1). The photoelectrochemical properties of the photocatalyst indicated that TiO2(R-A) HPJs and Ti3C2Tx SHJs have synergistic effects on the separation of photogenerated charges. Under the condition of photoexcitation, the photogenerated charge generated by TiO2 was separated at the rutile/anatase interface and transferred in the form of type II heterojunctions. Owing to the effect of Ti3C2Tx SHJs, it can quickly transfer and store holes on TiO2. Thus, the photocatalyst had remarkable photogenerated charge separation efficiency; TiO2(R-A)/Ti3C2Tx-200 degrees C-15 h had the strongest photocatalytic performance. This provides a new way to rationally design homogeneous heterojunctions for photocatalytic applications.