Ultrasonic-assistant fabrication of cocoon-like Ag/AgFeO2 nanocatalyst with excellent plasmon enhanced visible-light photocatalytic activity.

The AgFeO2 delafossite was reported as a potential photocatalyst as well as its intense recombination rate of photogeneration charge carriers. In this work, we utilized plasmon modification method to enhance the photocatalytic activity of AgFeO2. Silkworm cocoon like Ag/AgFeO2 nanocatalyst was synthesized by an ultrasonic enhanced reduction method. XRD, HRTEM and XPS results demonstrated the well dispersed Ag0 on the surface of AgFeO2. Under visible light irradiation, 20mg/L of ARG solution was completely degraded by 0.25g/L of Ag/AgFeO2 photocatalyst with pseudo-first-order rate of 0.040min-1. The inducement of the prominently enhanced photocatalytic activity of Ag/AgFeO2 was deeply analyzed. Significant decreased intensity of photoluminescence (PL) spectra suggested the superior separation of photo-induced electrons and holes of Ag/AgFeO2 as compared to that of AgFeO2. The free h+ was confirmed as the dominant active species for the pollutant degradation. Ultimately, the photodegradation mechanism was proposed and discussed.