Reinforce of hydrotalcite-like loaded TiO2 composite material prepared by Ti-bearing blast furnace slag for photo-degradation of tetracycline

Abstract

In this study, a composite material of hydrotalcite-like loaded TiO2 (TiO2@Mg-Al LDH) was prepared from Ti-bearing blast furnace slag (Ti-BFS) and used for photo-catalytic degradation of tetracycline (TC) in aqueous solution. The results of SEM, XRD, XRF, FT-IR, BET and UV-Vis DRS showed that photocatalytic TiO2@Mg-Al LDH was layered double hydroxide loading TiO2 structure and doped with metal elements, which could effectively induce the excitation wavelength of TiO2 to extend from UV to visible region. At the initial TC of 20?mg/L, the removal rate of TC and TOC were more than 90% and 72% within 120?min using UV in combination with TiO2@Mg-Al LDH. The radical quenching tests and EPR analysis indicated that TC degradation and mineralization were attributed to production of abundant OH• radicals, •O2- and h+ under UV conditions, which performed different proportion of removal, compared with adsorption experiment under non-light irradiation. Qualitative analysis of the by-products showed the aromatic ring of TC was opened, which effectively reduced the virulence of by-products. It indicated that the synergistic effect of hydrotalcite-like structure and photocatalysis could achieve efficient photodegradation of TC by TiO2. TiO2@Mg-Al LDH synthetized by high Ti-bearing blast furnace slag presented a good prospect of removing trace organic pollutants under synergistic effect of adsorption and UV photo-catalytic.