Adsorption and photocatalytic degradation investigation of organic dyes on TiO2 bentonite surface in aqueous solution

Abstract

This work investigates the adsorption and the photocatalytic degradation performance of dyes (methylene blue (MB) and methyl orange (MO)) on the surface of raw bentonite (Raw-B) and doped bentonite with titanium oxide (TiO2-B). The bentonite was selected from the Nador region in northern Morocco, it was doped with various TiO2 mass ratios. The structural, mineralogical and morphological composition of Raw-B and TiO2-B was characterized using several techniques including inductively coupled plasma atomic emission spectroscopy, X-ray diffraction, Fourier-transform infrared, transmission electron microscopy, and energy-dispersive X-ray analysis. The adsorption process of MB and MO were affected according to the Langmuir and Freundlich isotherms. The maximum removal capacity of MB and MO were around 60.97 and 142.85 mg/g, respectively. MB and MO degression ratios achieved 100% under a lamp irradiation at 245 nm. The results obtained show that the application of titanium oxide-doped bentonite has a very high performance in wastewater treatment.