High performance efficiency of water purification using Cr2O3 nanoparticles synthesized by thermal combustion technique

Abstract

Chromium (III) oxide (Cr2O3) nanoparticles (NPs) have been synthesized by thermal combustion technique. X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM) and thermal gravimetric analysis (TGA) were used to investigate Cr2O3 NPs. Photocatalytic efficiency of the Cr2O3 NPs as a catalyst was estimated by studying the degradation rate of methylene blue (MB) in wastewaters. XRD is indicated to the polycrystalline Rhombohedral structure of Cr2O3 with the lattice parameters: a = 0.5354 nm, α= 55.13° and space group R3c. HR-TEM image shows that the small particles have a nearly hexagonal shape with diameter around of 30 nm. The calculated optical band gap of Cr2O3 NPs is 3.16 eV, which is close to the previously published data. The rate kinetic constant (k app) was estimated around of 0.007 15 min-1. From these observed results of the present work, it is believed that the high efficiency of Cr2O3 NPs in MB wastewaters will be an indicator of high performance in water purification.