Photodegradation of organic dyes by CeO<inf>2</inf>/Bi<inf>2</inf>WO<inf>6</inf>nanocomposite and its physicochemical properties investigation

Abstract

© 2016 Elsevier Ltd and Techna Group S.r.l. The CeO2/Bi2WO6nanocomposite was synthesized by coupling of precipitation and hydrothermal methods. A detailed study of the physicochemical properties of CeO2/Bi2WO6nanocomposite were investigated by XRD, TEM, BET-specific surface area, UV–vis DRS, XPS, zeta potential, and PL techniques. The photocatalytic activities of CeO2/Bi2WO6nanocomposite was evaluated for the degradation of methylene blue (MB), rhodamine B (RhB) and the mixed dyes of MB and RhB under visible light irradiation. The CeO2/Bi2WO6nanocomposite presents excellent photocatalytic degradation of MB, RhB, and the mixed dyes of MB and RhB. The enhanced photocatalytic activity was originated from the migration efficiency of photogenerated charge carriers on the interface of CeO2and Bi2WO6. Moreover, the active species trapping experiments demonstrated holes (h+) and hydroxyl radical (OH⋅) were major active species in the degradation of RhB and MB, respectively. Herein, we also investigate the produced hydroxyl radical as a main oxidant in photocatalysis process for improving photocatalytic performance. Moreover, the CeO2/Bi2WO6nanocomposites shows excellent cycle stability toward continuous five cycles runs of photocatalytic experiment for dyes degradation. The possible photocatalytic mechanism of CeO2/Bi2WO6nanocomposite was described.