Graphdiyne based CoWO4/NC heterojunction boosting photocatalytic hydrogen production

Abstract

Graphdiyne (GDY), an innovative 2D carbon material, has received substantial interest for its superior conductivity, adaptable electronic configuration, and unique electron-electron transfer amplification features. CWN (CoWO4/NC) and GDY were used to prepare CWN/GDY via the electrostatic self-assembly method. The hydrogen production of CWN/GDY-1:1 was tangibly increased compared with that of CWN and GDY alone, and reached 3455 μmol∙ g-1∙ h-1. The photocatalytic hydrogen production of CWN/GDY-1:1 was 3.37 times that of CWN. The existence of this complex was confirmed by the analysis of structure, morphology, and elemental composition. CWN and GDY have the necessary conditions to produce heterojunctions since SEM and TEM images show that they are in extremely close contact. The electron transfer between the two can be found by XPS. Electrons are transferred from the CB of CWN to the CB of GDY for the synthesis of hydrogen, while holes are transferred at different rates from the VB of CWN to the VB of GDY. By creating a heterojunction, photogenerated electrons can travel faster and photosynthetic electrons cannot attach to holes. To sum up, the CWN/GDY-1:1 composite exhibits strong photocatalytic activity and stability, which provides valuable guidelines for tungstate composites and has great application potential in photocatalysis.