Novel ZnO/Ag2CrO4 nanocomposites with n–n heterojunctions as excellent photocatalysts for degradation of different pollutants under visible light

• Published in: Journal of materials science. Materials in electronics Vol. 27; no. 4; pp. 4098 - 4108
• Main Authors: Pirhashemi, Mahsa, Habibi-Yangjeh, Aziz
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2016
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Materials Science; Optical and Electronic Materials; Methylene Blue; Degradation Reaction; Photocatalytic Activity; Hole Pair; Methyl Orange
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-015-4269-4

Novel ZnO/Ag 2 CrO 4 nanocomposites, as excellent visible-light-driven photocatalysts, were successfully prepared with different weight percents of Ag 2 CrO 4 using a facile refluxing method at 96 °C. The phase, purity, morphology, and electronic properties of the resultant samples were characterized using XRD, EDX, SEM, TEM, UV–Vis DRS, FT-IR, and PL techniques. The nanocomposite with 30 % of Ag 2 CrO 4 was selected as the best photocatalyst for degradation of rhodamine B under visible-light irradiation. Activity of this nanocomposite is about 16-, 20-, and 25-fold greater than that of the ZnO in degradation of rhodamine B, methylene blue, and methyl orange, respectively. The excellent activity of the nanocomposites was attributed to more visible-light absorption ability, due to presence of narrow band gap Ag 2 CrO 4 , and fast separation of the photogenerated charge carriers, due to formation of n–n heterojunctions between ZnO and Ag 2 CrO 4 . Furthermore, the influence of preparation time, calcination temperature, and scavengers of the reactive species on the photocatalytic activity was studied and the results were discussed.