Direct Z-scheme g-C3N4/TiO2 heterojunction porous nanotubes: An ingenious synthesis strategy to enhance photocatalytic activity

Photocatalysis has a broad prospect for generating H2 and reactive oxygen species. In this study, porous nanotubular g-C3N4/TiO2 photocatalysts were obtained via electrospinning combined with an innovative vapor deposition approach. The waste foam was used as the precursor material for TiO2 nanotubes, reducing production cost and benefiting resource recovery. The modification of g-C3N4 onto TiO2 nanotubes provided extensive active sites with an increased specific surface area and produced the heterojunction to improve charge separation. The g-C3N4/TiO2 nanotubes displayed remarkable photocatalytic effects in the degradation of organic dye with a removal efficiency of 93.4% and H2 evolution reaction performing at 4122 μmol·g−1·h−1 under simulated sunlight. Photocatalytic activation product analyses and density functional theory (DFT) calculations demonstrated a possible photogenerated carriers transfer pathway. This work provides a way to prepare multifunctional porous nanotubes using a facile synthesis method from abandoned resources with implications for environmental remediation and hydrogen generation.