TiO2/BiOX (X=Cl, Br, I) hybrid microspheres for artificial waste water and real sample treatment under visible light irradiation

[Display omitted] •TiO2/BiOX (X=Cl, Br, I) nano-assembled microspheres were synthesized by a solvothermal method.•Adsorption and photocatalytic dye degradation were tested for pure orange G and tartrazine under visible light.•Adsorption and photocatalytic dye degradation were tested for mixed dye (MO+RhB+MB) under visible light.•Adsorption and photocatalytic dye degradation were tested for natural dyes and commercial drinks under visible light.•H2O2 addition effects on photocatalytic dye degradation were examined. The hybridization of two different materials is important for achieving improved photocatalytic degradation properties. Generally, photocatalysts do not show good linear catalytic performance toward all the dyes. This paper reports the synthesis of nano-assembled TiO2/BiOX (X=Cl, Br, or I) hybrid microspheres, which were confirmed by powder X-ray diffraction, field emission scanning electron microscopy, electron transmission microscopy, UV–visible spectroscopy, Fourier-transform infrared spectroscopy, and photoluminescence spectroscopy. The synthesized photocatalysts were examined extensively for their photocatalytic activities with single (orange G and tartrazine), mixed dyes (methyl orange+rhodamine B+methylene blue), natural dyes extracted from grapes and cabbages (real sample analysis) as well as a commercially available drink with and without H2O2 addition under visible light irradiation. For the mixed dyes, TiO2/BiOI showed the highest adsorption capacity and TiO2/BiOCl showed the highest photocatalytic activity. Methyl orange in the mixed dyes was the most rapidly photodegraded of all the photocatalysts examined. TiO2/BiOI showed the highest photocatalytic activity for orange G and tartrazine. The three different photocatalysts showed effective and uniform degradation activity to the natural dyes obtained from grapes and cabbages. The dye degradation was enhanced by H2O2 addition.