In situ synthesis of g-C3N4/TiO2 with {001} and {101} facets coexposed for water remediation

Abstract

A relatively simple and bottom-up method has been developed for the preparation of g-C3N4/TiO2 nanocomposites with coexposed {001} and {101} facets. Under acid-assisted hydrothermal conditions, the supramolecular preassembly of triazine precursor was resulted from the coordination of melamine with induced cyanuric acid, and synchronized with the large-scale etching of TiO2. Consequently, the g-C3N4/TiO2 nanocomposites with coexposed {001} and {101} facets have been prepared via the simple heat treatment process. As the sintered precursor, the self-assembled supramolecules serve as a viable means for simultaneously controlling the compact and uniform contact interfaces between g-C3N4 and TiO2. As a result, the obtained samples exhibit excellent visible photocatalytic performance for the degradation of organic pollutants and inactivation of Escherichia coli K-12 as compared to pristine g-C3N4 and TiO2. The reactive O2– and photoinduced holes are found to play the major roles in the photocatalytic behavior due to the energy band structure of the materials. Our results suggest that the self-assembled supramolecules can serve as the sintered precursor to prepare a high photocatalytic performance material on the field of water treatment, and pave alternative synthetic method for composites based on conjugated polymers and metallic compound.