Construction of 3D flower-like FeTiO3/MoS2 heterostructure photocatalyst for degradation of tetracycline hydrochloride

Abstract

Materialsof two-dimensional structure have been extensively studied for their prospect in the field of photocatalysis research. In this research, an innovative composite of 3D flower-like MoS2 coated with FeTiO3 nanoparticles was designed and prepared to solve the problems of water environmental pollution using a simple sol-gel method and hydrothermal method. Surface morphology and microstructure were investigated, which indicates that MoS2/FeTiO3 heterojunction structure was fabricated successfully, compared with the pristine materials, enabled increased Brunauer-Emmett-Teller (BET) surface area, the strengthen of light utilization and more efficient separation efficiency of photoexcited charge in the interfacial electric field. Correspondingly, the MoS2/FeTiO3 photocatalyst exhibits the excellent visible-light-responsive photocatalytic activity for the degradation of tetracycline hydrochloride (TCH), which was 0.02121 min−1 by MoS2/FeTiO3 photocatalyst with the optimized condition. The scavenger tests of reactive oxidation species scavenger (ROSs) demonstrate that the enhanced degradation activity of TCH is ascribed to the existence of the photoexcited hole (h+), superoxide radicals (∙O2−) and hydroxyl radicals (∙OH). The results of ROSs and Mott-Schottky (M-S) indicate that band bending is formed for MoS2/FeTiO3 composites with the orientation of the interface electric field form FeTiO3 to MoS2 due to the fact that the Fermi level of FeTiO3 is higher than that of MoS2, resulting in the transfer of photoexcited electron from MoS2 to conduction band (CB) of FeTiO3, and the photoexcited holes from FeTiO3 to valence band (VB) of MoS2. And the charge transfer process of Ⅱ-type heterostructure is proposed according to the energy band structure of MoS2 and FeTiO3, as well as the results of experiments. Therefore, we believe that our well-designed MoS2/FeTiO3 heterostructure effectively contributes to the progress of photocatalytic degradation and the treatment of water pollution.