In-situ preparation of MIL-125(Ti)/Bi2WO6 photocatalyst with accelerating charge carriers for the photodegradation of tetracycline hydrochloride

Abstract Metal organic frameworks (MOFs), an emerging organic-inorganic hybrid material, which has shown great development prospects in photocatalysis. In this paper, a type of Ti-MOF (MIL-125) was prepared. Bi2WO6 nanosheets were in-situ formed on the outer surface of MIL-125(Ti) to construct MIL-125(Ti)/Bi2WO6 composites. The crystalline structures of the composites were explored by XRD, XPS and FT-IR, the morphologies were scrutinized employing SEM and TEM characterizations, the photochemistry and electrochemistry performance of the samples were studied via DRS, PL, EIS and transient photocurrent analysis. The results show that the composites possess lager specific surface area, higher visible-light harvest as well as stronger photocurrent compared to the pure material, which matched the enhanced photocatalytic performance. The 5 wt% MIL-125(Ti)/Bi2WO6 composites showed the best performance. Superoxide radicals and holes were the staple active substances for photodegradation from the ESR and free radicals trapping tests, and the possible photocatalytic mechanisms were deduced.