Present study deals with the sol-gel synthesis and application of α-Al₂O₃ nanoparticles (alumina) to decolorize the azo anionic dye methyl orange (MO). α-Al₂O₃ nanoparticles were successfully synthesized using aluminium oxide, 25% ammonia and polyvinyl alcohol (PVA) were used as low cost raw materials. The properties of synthesized nanoparticles were investigated by using UV-visible spectroscopy, XRD, FTIR, SEM, EDAX, Raman spectroscopy and TEM. From UV–visible spectra, band gap was calculated and it was found to be 3.31 eV. Average crystal size of α-Al₂O₃ nanoparticles from XRD peaks found to be 25 nm having rhombohedral structure. FTIR spectra reveals that functional groups (O-Al-O) are present. SEM image shows distribution pattern of α-Al₂O₃ nanoparticles. Chemical composition of α-Al₂O₃ nanoparticles was confirmed from EDAX spectroscopy measurement. Raman spectra showed crystalline nature of α-Al₂O₃ nanoparticles. The effect of concentration and pH of dye, dosage of nano adsorbent and contact time were studied. The systematic study shows that, successful color removal of methyl orange dye up to 54% in three hours contact time of pH 4. Hence α-Al₂O₃ nanoparticles can be used for dye removal from waste water. Industrialization of this technique will be cost effective way to decolorize the textile dye present in water system.

Keywords: Sol-Gel Method; α-Al₂O₃ Nanoparticles; Azo Dye; Decolorization;