Low-temperature synthesis of α-Fe2O3 hexagonal nanoparticles for environmental remediation and smart sensor applications

This work demonstrates the successful synthesis and characterizations of alpha-Fe2O3 hexagonal nanoparticles and their effective utilization for the degradation of hazardous Rhodamine B (RhB) dye and smart chemical sensor applications. The as-synthesized materials were characterized by various analytical techniques which revealed that the prepared nanoparticles are well-crystalline, possessing hexagonal shape, grown in high-density and well matched with the rhombohedral alpha-Fe2O3 structures. The as-synthesized alpha-Fe2O3 nanoparticles were used as efficient photocatalyst for the photocatalytic degradation of RhB-dye under light illumination which showed substantial degradation (similar to 79%) of RhB-dye in 140 min. The considerable photo-degradation of RhB-dye attributed to the unique morphology of the synthesized alpha-Fe2O3 nanoparticles which might import the effective electron/hole separation and generate the large number of oxy-radicals. Moreover, the synthesized alpha-Fe2O3 nanoparticles were utilized as efficient electron mediators for the fabrication of 4-nitrophenol chemical sensor in aqueous media. The fabricated chemical sensor exhibited a high-sensitivity of similar to 367.6 mu A (mol L-1)(-1) cm(-2) and an experimental detection limit of similar to 1.56 x 10(-3) mol L-1 in a short response time of similar to 10.0 s with linearity in the range of 1.56 x 10(-3)-12.5 x 10(-3) mol L-1 and correlation coefficient (R) of similar to 0.99963. These investigations demonstrated that the simply synthesized alpha-Fe2O3 nanoparticles can effectively be used as efficient photocatalyst for the photocatalytic degradation of organic dyes and effective electron mediators for the fabrication of highly sensitive chemical sensors in aqueous medium. (C) 2013 Elsevier B.V. All rights reserved.