Novel TiO2/Ag2CrO4 nanocomposites: Efficient visible-light-driven photocatalysts with n-n heterojunctions

In this study, novel TiO2/Ag2CrO4 nanocomposites were fabricated by a facile refluxing method using commercial TiO2, silver nitrate, and sodium chromate at low temperature of 96 degrees C. The as -prepared photocatalysts were characterized by XRD, EDX, SEM, TEM, UV-vis DRS, FT-IR, BET, and PL techniques. Compared with the TiO2 sample, TiO2/Ag2CrO4 nanocomposites exhibited highly enhanced photo catalytic activity in degradations of rhodamine B (RhB), methylene blue (MB), and fuchsine dyes under visible -light irradiation. Among the prepared photocatalysts, the TiO2/Ag2CrO4 (50%) nanocomposite showed the superior activity of 8.8, 5.4, and 44-folds relative to the TiO2 sample in degradations of RhB, MB, and fuchsine, respectively. The trapping experiments demonstrated that holes and superoxide anion radicals were the main reactive species in the degradation reaction. Based on the obtained results, the photocatalytic activity enhancement was attributed to strong visible -light absorption, effective separation of photogenerated charge carriers by internal electrostatic field produced through n-n heterojunction formed between counterparts of the nanocomposite, and enhanced surface area. (C) 2017 Elsevier B.V. All rights reserved.