Visible light induced efficient photocatalytic hydrogen production by graphdiyne/CoSe ohmic heterojunction

Abstract

The discovery of graphdiyne (GDY) represents a significant advancement in the field of carbon allotropes, and has garnered widespread attention for its potential applications in hydrogen production. Lamellar graphdiyne (GDY) synthesized via the ball milling method serves as a good carrier for preparing a composite photocatalyst. Modified with flower-ball CoSe particles, the GDY/CoSe ohmic junction composite photocatalyst has been reasonably designed. The GDY/CoSe-15 photocatalyst (15 wt% CoSe) exhibited stable photocatalytic H₂ evolution activity. It was capable of achieving a rate of 2.54 mmol h⁻¹ g⁻¹, which was 8.7 and 6.1 times higher than the respective rates of GDY (0.29 mmol h⁻¹ g⁻¹) and CoSe (0.42 mmol h⁻¹ g⁻¹). The experimental findings and density functional theory (DFT) calculations indicate that the GDY/CoSe photocatalyst demonstrates exceptional light absorption capacity and effectively separates photogenerated carriers. Furthermore, the CoSe cocatalyst has the potential to function as an electron acceptor, facilitating the efficient transfer and transportation of photogenerated electrons; as a result, this enhances the efficiency of photocatalytic hydrogen production.