High-efficiency visible-light AgI/Ag/Bi2MoO6 as a Z-scheme photocatalyst for environmental applications

Abstract

A novel ternary composite AgI/Ag/Bi₂MoO₆ photocatalyst was successfully synthesized by a facile hydrothermal method combined with an ultrasonic-assisted precipitation-photoreduction technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence emission spectra (PL) analysis were employed to characterize the composition, phase structures, crystallinity, morphologies and optical properties of the obtained catalysts. The experimental results indicated that the AgI/Ag/Bi₂MoO₆ (15.0%) composite display higher visible light photoactivity for organic pollutants degradation compared with pure Bi₂MoO₆ and Ag/AgI nanocrystals. On the basis of band structure analysis and active species trapping experimental results, the excellent photocatalytic performance of the AgI/Ag/Bi₂MoO₆ photocatalysts can be ascribed to the efficient electron transfer and lower recombination of photogenerated electron–hole pairs through the Z-scheme system. And the Ag nanoparticles act as the charge transmission bridge in the process. The physicochemical features and high degradation efficiencies were maintained after five cycling experiment, indicating that the samples exhibited good durability and stability. It is expected that the novel AgI/Ag/Bi₂MoO₆ hybrid is a promising candidate material for the environmental applications.