Insight on the plasmonic Z-scheme mechanism underlying the highly efficient photocatalytic activity of silver molybdate/silver vanadate composite in rhodamine B degradation.

A facile deposition-precipitation method was applied to synthesize novel plasmonic Z-scheme Ag2MoO4/Ag3VO4 photocatalysts with different molar ratios of Ag2MoO4. The morphological, structural, and spectroscopic properties of the as-obtained samples were characterized through X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectral analysis. The photocatalytic performance of the synthesized photocatalysts in rhodamine B (RhB) degradation under visible light irradiation was evaluated. The 5% Ag2MoO4/Ag3VO4 composite displayed the highest photocatalytic activity among all samples and the RhB removal rate of 93% within 6 min. The RhB removal rate of 5% Ag2MoO4/Ag3VO4 composite was higher than that of precursor Ag2MoO4 and Ag3VO4 compounds. The formation of Ag nanoparticles (Ag NPs) on the surface of Ag2MoO4/Ag3VO4 during photocatalysis resulted in the transformation of the Ag2MoO4/Ag3VO4 heterojunction to the Ag2MoO4/Ag/Ag3VO4 Z-scheme system, thus enhancing photocatalytic activity. Z-scheme Ag2MoO4/Ag/Ag3VO4 composites could efficiently facilitate charge transfer, promote redox ability, and restrain Ag3VO4 photocorrosion. The produced active species O2-, h+, and OH are vital for RhB degradation. The present work could benefit the development of advanced visible-light photocatalytic materials with future applications in environmental remediation.