A selective ion replacement strategy for the synthesis of copper doped carbon nitride nanotubes with improved photocatalytic hydrogen evolution

Abstract

Developing new strategy to efficiently improve the photocatalytic activity of graphitic carbon nitride (g-C3N4) for hydrogen evolution is critical for its application in solar energy utilization. In this work, an innovative selective cation replacement process is developed to synthesize copper doped g-C3N4 nanotubes driven by the ion–dipole interaction of metal ions in g-C3N4. The tri-s-triazine units may act as stable frameworks in the sequential cation exchange reaction process, which subsequently leads to the formation of Cu doped g-C3N4 with high specific surface area and nanotube structures. The obtained g-C3N4 exhibits greatly enhanced visible-light-driven hydrogen evolution of 3.02 mmol h−1 g−1, which is about 13 times higher than that of pristine one. Detailed characterization reveals the underlying mechanism of the improved photocatalytic performance on the newly developed g-C3N4, which can provide valuable guides to rationally design new efficient photocatalysts.