In situ synthesis of graphitic-C₃N₄ nanosheet hybridized N-doped TiO₂ nanofibers for efficient photocatalytic H₂ production and degradation

Graphitic carbon nitride nanosheets (g-C₃N₄ NSs) hybridized nitrogen doped titanium dioxide (N-TiO₂) nanofibers (GCN/NT NFs) have been synthesized in situ via a simple electrospinning process combined with a modified heat-etching method. The prepared GCN/NT NFs were characterized by a variety of methods and their photocatalytic activities were evaluated by hydrogen (H₂) production from water splitting and degradation of rhodamine B in aqueous solution. It was found that the GCN/NT NFs have a mesoporous structure, composed of g-C₃N₄ NSs and N-doped TiO₂ crystallites. The g-C₃N₄ NSs synthesized after heat-etching were found to be embedded in, and covered, the hybrid NFs to form stable interfaces. The partial decomposition of g-C₃N₄ releases its nitrogen content which eventually gets doped into the nearby TiO₂ skeleton. The GCN/NT NFs give a high photocatalytic H₂ production rate of 8, 931.3 μmol·h^-1·g^-1 in aqueous methanol solution under simulated solar light. Such a highly efficient photocatalytic performance can be ascribed to the combined effects of g-C₃N₄ NSs and N-doped TiO₂ with enhanced light absorption intensity and improved electron transport ability. Also, the large surface area of the mesoporous NFs minimizes light reflection on the surface and provides more surface-active sites. This work highlights the potential of quasi-one dimensional hybrid materials in the field of solar energy conversion.