Surface Modification of NiO‐Al2O3 Nanocomposites using Stearic Acid as a Modifier and their Applications in Self‐cleaning and Removal of Dyes

Abstract

AbstractIn the present study, a quick surface modification method has been developed for the modification NiO‐Al2O3 nanocomposites using stearic acid (SA). The surface modification of NiO‐Al2O3 nanocomposites with stearic acid was confirmed by various analytical techniques (FT‐IR spectroscopy, thermal gravimetry (TG), carbon and hydrogen (CH) and XPS). There is no change in XRD patterns, and FE‐SEM and TEM images of NiO‐Al2O3 nanocomposites after modification with SA. FT‐IR analysis of SA modified NiO‐Al2O3 nanocomposites shows characteristic IR bands of carboxylate group. TG and CH analyses also confirm the presence of SA in the NiO‐Al2O3 nanocomposites. XPS analysis of SA modified NiO‐Al2O3 nanocomposites shows the presence of carbon atoms of stearic acid. The SA modified NiO‐Al2O3 nanocomposites show water contact angle greater than 90° which suggests their hydrophobic nature. The SA modified NiO‐Al2O3 nanocomposites were explored for self‐cleaning and also as adsorbent for the removal of crystal violet and rhodamine B dyes from aqueous solutions. The SA modified NiO‐Al2O3 nanocomposites remove the dyes within 30 minutes. The effect of various adsorption parameters (adsorbent dosage, contact time, pH, and temperature) was investigated to understand the optimum adsorption conditions. The SA modified NiO‐Al2O3 nanocomposites show better self‐cleaning property as compared to unmodified NiO‐Al2O3 nanocomposites.