Ag/rGO/Bi2WO6 nanocomposite as a highly efficient and stable photocatalyst for Rhodamine B degradation under visible light irradiation

Abstract

An efficient Ag/rGO/Bi2WO6 nanocomposite was synthesized by the precipitation-photoreduction method. The resulting Ag/rGO/Bi2WO6 showed excellent photocatalytic activity for the photodegradation of Rhodamine B (RhB), with 15%Ag/rGO/Bi2WO6 photodegrading 96.97% of RhB in 180 min, which was 1.28, 1.09 and 1.05 times higher than that of Bi2WO6, Ag/rGO, and rGO/Bi2WO6, respectively. The effect of noble metal Ag's surface plasmon resonance and Schottky barrier, as well as the superior electron transfer ability of rGO, dramatically improved photo-generated electron-hole pair separation and transfer efficiency. In addition, the effects of pollutant concentration, pH, and catalyst dosage on Ag/rGO/Bi2WO6 photocatalytic performance also were explored. Furthermore, the free-radical trapping tests revealed that the primary active radicals in the catalytic system are hole (h+), superoxide radical (•O2−), and hydroxy radical (•OH). Additionally, after four recycling, the photocatalytic performance of the Ag/rGO/Bi2WO6 composite did not show a significant decline. As a result of this research, the Ag/rGO/Bi2WO6 catalyst, as developed, has a bright potential for environmental purifying.