Photocatalytic properties of Ba3Li2Ti8O20 sol–gel

Abstract

Samples of Ba₃Li₂Ti₈O₂₀ were prepared by the sol–gel method at pH 3 and 9 using acetic acid and ammonia hydroxide respectively as hydrolysis catalysts. The band gap (E_g) of the solids prepared was calculated from the UV-Vis absorption spectra of samples thermally treated at different temperatures, the values obtained ranging from 3.37 to 3.09 eV. The E_g values of the powders synthesized at pH 9 were higher than those of samples prepared at pH 3. Surface characterization of the solids was carried out from adsorption isotherms and FTIR studies, and their photocatalytic activities on 2,4-dinitroaniline degradation were also measured. The decomposition rate followed Langmuir–Hinshelwood kinetics. According to the calculated kinetic parameters, better results were obtained once the crystalline structure of Ba₃Li₂Ti₈O₂₀ had formed.