Synthesis of plasmonic enhance sphere-like Ag/AgI/Bi5O7I photocatalysts with improved visible-light responsive activity under LED light irradiation

Abstract

Coupling surface plasmon with semiconductor has been demonstrated to be an efficient strategy for improving the photocatalytic performance of the photocatalyst. The sphere-like Ag/AgI/Bi5O7I composites were synthesized by a hydrothermal-decomposition process, followed by an in-situ ion exchange reaction. Under LED lamp irradiation (400 < λ < 800 nm), the as-prepared Ag/AgI/Bi5O7I displayed a great enhancement in photocatalytic activities for the degradation of organic dyes (Rhodamine B and methyl orange), as compared with the pure orthorhombic phase Bi5O7I. The scavenger test results indicated that the photo-generated h+ would play an important role in the degradation of organic pollutants. Moreover, the Ag/AgI/Bi5O7I nanocomposite generates high photoactivity in the cycling photocatalytic test. According to the experimental results, the possible photocatalytic degradation mechanism of Ag/AgI/Bi5O7I was also proposed. From our perspective, this advantage is mainly ascribed to two aspects: (i) the surface plasmon resonance effect of Ag nanoparticles; (ii) the highly efficient separation of electrons and holes through the closely contacted interfaces in the Ag/AgI/Bi5O7I system.