Different nanostructured In₂O₃ for photocatalytic decomposition of perfluorooctanoic acid (PFOA).

Perfluorooctanoic acid (PFOA), an emerging persistent organic pollutant, recently receives worldwide concerns including methods for its efficient decomposition. Three kinds of nanostructured In₂O₃ materials including porous microspheres, nanocubes and nanoplates were obtained by dehydration of the corresponding In(OH)₃ nanostructures at 500 °C for 2 h. The In(OH)₃ nanostructures with different morphologies were solvothermally synthesized by using different mixed solvents. As-obtained In₂O₃ nanomaterials showed great photocatalytic activity for PFOA decomposing. The decomposition rates of PFOA by different In₂O₃ materials, i.e. porous microspheres, nanoplates and nanocubes were 74.7, 41.9 and 17.3 times as fast as that by P25 TiO2, respectively. The In₂O₃ porous microspheres showed the highest activity, by which the half-life of PFOA was shortened to 5.3 min. The roles of surface oxygen vacancies on the adsorption and photocatalytic decomposition of PFOA were discussed, and it was found that In₂O₃ materials with higher oxygen vacancy defects show better activity.