High performance photocatalyst TiO2@UiO-66 applied to degradation of methyl orange

Abstract

MOFs have considerable adsorption capacity due to their huge specific surface area. They have the characteristics of photocatalysts for their organic ligands can absorb photons and produce electrons. In this paper, the photodegradation properties of TiO₂ composites loaded with UiO-66 were investigated for the first time for MO. A series of TiO₂@UiO-66 composites with different contents of TiO₂ were prepared by a solvothermal method. The photocatalytic degradation of methyl orange (MO) was performed using a high-pressure mercury lamp as the UV light source. The effects of TiO₂ loading, catalyst dosage, pH value, and MO concentration were investigated. The results showed that the degradation of MO by TiO₂@UiO-66 could reach 97.59% with the addition of only a small amount of TiO₂ (5 wt%). TiO₂@UiO-66 exhibited significantly enhanced photoelectron transfer capability and inhibited efficient electron–hole recombination compared to pure TiO₂ in MO degradation. The composite catalyst indicated good stability and reusability when they were recycled three times, and the photocatalytic reaction efficiencies were 92.54%, 88.76%, and 86.90%. The results provide a new option to design stable, high-efficiency MOF-based photocatalysts.