Photocatalytic degradation of organic dyes using TiO2 nanotube arrays and aero-ZnO- ZnS under UV and visible light illumination

We report on the results of comparative study of the photocatalytic performances of the wide band gap semiconductor catalysts titania (TiO
₂
), zinc oxide (ZnO) and mixed phase of ZnO-ZnS (zinc sulfide). The mixed phase structures show better photodegradation properties under UV and visible light illumination compared to its analogous forms. Rutile phase TiO
₂
nanotubes showed the highest catalytic activity, resulting in 70% decay of dye concentration within 85 min with visible light irradiation, while the rutile-anatase mixture of TiO
₂
degrade 75% of the test contaminant within 10 min under UV illumination. Microparticles and assemblies of nanostructures used in the experiments can be recycled effectively and subsequently reused.