Enhanced visible-light photocatalytic activity and stability over g-C₃N₄/Ag₂CO₃ composites

A facile direct growth method was developed for the fabrication of Ag₂CO₃ nanoparticles on the surface of g-C₃N₄ at room temperature. The as-prepared g-C₃N₄/Ag₂CO₃ composites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy with energy dispersion X-ray spectroscopy, UV–vis diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The photocatalytic activities were evaluated by degrading Rhodamine B dye. The results indicated that Ag₂CO₃ nanoparticles with the size of 5–10 nm were finely distributed on the surface of g-C₃N₄ sheet, leading to the enhancement of the photocatalytic activity. And when the mass ratio of g-C₃N₄ to Ag₂CO₃ was 1:4, the as-prepared composites exhibited the optimum photocatalytic activity, which was approximately 8 and 3 times higher than pure g-C₃N₄ and Ag₂CO₃, respectively. The enhanced photocatalytic performance could be attributed to the synergetic effects between g-C₃N₄ and Ag₂CO₃, including the smaller particle size of Ag₂CO₃ and high charge separation efficiency of the photogenerated electron–hole pair. More attractively, the stability of Ag₂CO₃ was improved due to its highly dispersion on g-C₃N₄ sheet. In addition, based on the experimental results, the Z-scheme mechanism for the photodegradation over g-C₃N₄/Ag₂CO₃ composites was proposed.