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.

Synthesis of titanium dioxide and the study of photocatalytic activity

“…where η denotes the degradation rate of the methyl orange solution, A0 represents the absorbance of the solution before exposure to light, and At represents the absorbance of the solution after exposure for a specific time (t). The assessment of TiO2 particle photocatalytic degradation efficiency for methyl orange in aqueous solution involves measuring the change in absorbance before and after exposure to light at the maximum absorption wavelength (465 nm) by using a UV-visible spectrophotometer [7] .…”