Photocatalytic H2 evolution on graphdiyne/g-C3N4 hybrid nanocomposites

Abstract

Hydrogen is considered an ideal alternative energy source to replace fossil energy. Herein, a novel graphdiyne (GD)/graphitic carbon nitride (g-C3N4) nanocomposite was successfully synthesized via a facile calcination approach, and display excellent H2-generation performance under visible light. When the mass ratio of GD reaches 0.5 wt% in GD/g-C3N4 nanocomposite, it shows a maximum hydrogen evolution rate, exceeding that of g-C3N4 by 6.7-fold. After systematic characterization, a new CN bond is confirmed to form between GD and g-C3N4 following heat treatment, and this bond serves as a charge carrier channel that facilitates the migration of photogenerated electrons from g-C3N4 to GD. Positive effects, such as a prolonged photogenerated charge carrier lifetime, intensified electron density, decreased reaction overpotential and improved charge carrier mobility, also contribute to the enhanced photocatalytic performance of the nanocomposites. The proposed technique provides a promising approach for modifying photocatalysts in future applications.