MIL-100(Fe)/silica gel: controllable preparation and photocatalytic activation of peroxydisulfate for tetracycline hydrochloride degradation

Abstract

MIL-100(Fe) exhibits typical performances for photocatalytic activation of peroxydisulfate for tetracycline hydrochloride degradation due to its extensive internal Fe–O clusters. However, the practicability of MIL-100(Fe) is suppressed by its powder features. Herein, the growth of MIL-100(Fe) on a certain support involved with employing a highly porous, 3-dimensional (3D) silica gel as the substrate for MIL-100(Fe) is introduced to overcome the difficulties. The obtained MIL-100(Fe)/silica gel showed a regular bead shape and the load of MIL-100(Fe) was controllable. The silica gel not only acts as the growth template to balance the practicability and powder nature for MIL-100(Fe), but also offers a highly porous 3D structure which enables the successful flow of solutions through silica gel and promotes the interaction between solution molecules and MIL-100(Fe) by prolonging the contact time. Benefiting from the synergies between MIL-100(Fe) and silica gel, MIL-100(Fe)/silica gel showed enhanced photocatalytic activation of peroxydisulfate for tetracycline hydrochloride degradation, with the adsorption rate of 23%, degradation rate exceeding 90% within 60 minutes and the corresponding degradation constant value k of 0.0567 min⁻¹.