Preparation of Ag₂CO₃/Ag/g-C₃N₄ Z-scheme Heterostructure and Photocatalytic Degradation of Rhodamine B Under Visible Light

Abstract

The highly efficient Z-scheme photocatalyst Ag2CO3/Ag/g-C3N4 with Ag nanoparticles, as an electron mediator, was fabricated by a simple calcinations-precipitation reaction. Photocatalytic experiments of the as-prepared samples were tested by the photocatalytic oxidation degradation of RhB aqueous solution. The results show that Ag2CO3/Ag/g-C3N4 composites exhibit enhanced photocatalytic activity, compared with Ag2CO3 and g-C3N4. The composites exhibit the highest photocatalytic performance, when the mass ratio of g-C3N4 to Ag2CO3/Ag is 20%,which is attributed to the formation of Z-scheme heterojunction structure between Ag2CO3 and g-C3N4, thus accelerating electron transfer rate and separating efficiently the photo-generated electron-hole pairs. Meanwhile, the Z-scheme heterojunction structures extend the wavelength range of visible light absorption (from 450nm to 670nm) due to the surface plasma resonance (SPR) of Ag nanoparticles. The trapping experiment results confirm that·O2- and h+ are main active species,·OH plays a relatively minor role in the decomposition of RhB. A possible mechanism for enhanced photocatalytic activity of Ag2CO3/Ag/g-C3N4 heterojunction photocatalyst is proposed.

Keywords

• Ag₂CO₃/Ag/g-C₃N₄
• Z-scheme photocatalyst
• visible light
• photocatalytic activity