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.