The first study of adsorption of methylene blue by Black Titania (B-TiO2) nanoparticle in aqueous solution

In this study, the elimination of methylene blue (MB) by adsorption on Black Titania (B-TiO2) in an aqueous solution in the dark room is investigated. Preparation of B-TiO2 was carried out via the reduction of white TiO2 by NaBH4 in a tube furnace under an inert gas atmosphere at 600°C. Characterization of the absorbent was carried out by XRD, N2 adsorption-desorption, SEM mapping, photoluminescence, EDX analysis, Zeta potential, DLS, and FT-IR. The maximum adsorption capacity of B-TiO2 was found to be 88.65 mg g−1. The rate-limiting step was the intra-particle diffusion stage. The maximum adsorption was observed under the conditions: 26 mg of the B-TiO2 at pH 6 and MB concentration of 10 mg L−1. It was demonstrated that B-TiO2 might be recycled six times with very good adsorption results while keeping its high removal efficiency.