Comparative studies of the photocatalytic and microwave -assisted degradation of alizarin red using ZnO/poly(1-naphthylamine) nanohybrids

Semiconductors such as ZnO and TiO2 have been extensively utilized in the photocatalytic degradation of dyes. However till date, no study has been reported to compare the catalytic efficiency of such organic-inorganic hybrids under UV light and microwave irradiation separately. The present work reports the synthesis of poly(1-naphthylamine)/ZnO nanohybrids. The structure and morphology of the synthesized nanocomposites were characterized using FT-IR, DV, XRD, TEM and Cyclic voltammetry analyses. The dye degradation studies were done separately in a photochemical reactor and in laboratory microwave oven and the fragments were identified using LC-MS technique. Results showed that under microwave irradiation, the efficiency of ZnO/PNA as catalyst was higher as compared to DV irradiation. Higher extent of center dot OH radical generation was confirmed in microwave as compared to UV irradiation which was found to be responsible for the high rate of degradation of dye solution. A plausible degradation pathway was proposed. (C) 2016 Elsevier B.V. All rights reserved.