Excellent organic dye adsorption capacity and recyclability of hydrothermally synthesized α-Fe2O3 nanoplates and nanorices

Abstract

α-Fe2O3 and Fe3O4 nanoplates and nanorices were synthesized by hydrothermal reaction and used for organic pollutant adsorption and removal studies. The effect of size and morphology of α-Fe2O3 and Fe3O4 nanoplates and nanorices on the dye adsorption efficiency were investigated systematically. The adsorption studies showed a good selectivity and high adsorption capacity (~93%) of the α-Fe2O3 nanoplates towards congo red (C.R.) dye, due to the formation of hydrogen bonding between amine group (─ NH2) of C.R. and surface carboxylate group (─ COOH), and adsorbed ─ OH groups of α-Fe2O3 nanoplates. The α-Fe2O3 nanoplates also showed excellent recyclability with negligible loss of the adsorption capacity, owing to their stable morphology and crystal structure. The excellent C.R. adsorption capacity of the α-Fe2O3 nanoplates was further confirmed by conducting experiments with a solution containing a mixture of dyes. Our findings indicate that the synthesized α-Fe2O3 nanoplates have a great potential in removing industrial waste, such as C.R. from polluted water.