The OII was purchased from Alvan sabet company, Iran. The general characteristics of OII dye and the textile wastewater used in the present study are shown in Table S1 and S2, respectively [36 (link)–38 (link)]. Titanium (IV) isopropoxide (C12H28O4Ti, TTIP, Merck, 98%), 2-propanol (C3H8O, Merck, > 99%), potassium peroxymonosulfate (Oxone®, PMS, Sigma-Aldrich, CAS NO.:70693–62-8), sulfuric acid (H2SO4, 98%, Merck), sodium hydroxide (NaOH, 99%, Merck) and other reagents were analytical grade and used without further purification. Zinc oxide (ZnO) and iron oxide (Fe2O3) NPs were provided by NanoAmor Co (USA).