Truncated octahedral bipyramidal TiO2/MXene Ti3C2 hybrids with enhanced photocatalytic H2 production activity

Abstract

MXene Ti3C2/TiO2 hybrids were successfully synthesized through a simple calcination of F-terminated Ti3C2. The resultant Ti3C2/TiO2 composite photocatalysts retained a 2D multilayer structure like MXene Ti3C2, and TiO2 exhibited a truncated octahedral bipyramidal structure with exposed (001) facets under the participation of fluorine ions. The residual Ti3C2 could act as a co-catalyst to enhance the photocatalytic H2 production activity by capturing photogenerated electrons from TiO2 because of its electron reservoir feature and suitable Fermi level. The (101)-(001) surface heterojunction of the truncated octahedral bipyramidal TiO2 further accelerated the separation of photogenerated carriers. As a result, the Ti3C2/TiO2 hybrids with calcining F-terminated Ti3C2 exhibited photocatalytic hydrogen production that is twofold higher than that of Ti3C2/TiO2 hybrids with calcining OH-terminated Ti3C2. This work presented a new strategy to prepare MXene Ti3C2/TiO2 hybrids for photoconversion applications.