Abstract
Well-crystalline alpha-Fe2O3 nanourchins were successfully prepared via a facile hydrothermal method using dimethylsulfoxide (DMSO) as the growth template and characterized in detail in terms of their morphological, structural, compositional and photocatalytic properties. To understand the growth process for the formation of alpha-Fe2O3 nanourchins, several reaction time and DMSO amount dependant experiments were performed and it was found that reaction time and the amount of DMSO are critical parameters to obtain urchin-shaped morphologies. A plausible growth mechanism for the formation of alpha-Fe2O3 nanourchins was presented. The prepared alpha-Fe2O3 nanourchins were used as efficient photocatalyst for the photocatalytic degradation of three harmful organic dyes, i.e. Congo red (CR), Eosin red (ER) and methylene blue (MB) under visible light illumination. The order of degradation rate for all used dyes are MB (80%) < Eosin red (84%) < CR (98%). By comparing the photocatalytic performance towards Congo red dye with other photocatalysts such as dendrite-shaped alpha-Fe2O3 structures and commercially available TiO2 (P-25), it was observed that the prepared alpha-Fe2O3 nanourchins exhibited superior photocatalytic performance towards CR dye. Finally, the photocatalytic recycle tests were also performed which showed that the prepared alpha-Fe2O3 nanourchins were stable after even five cycles. The presented works demonstrates that alpha-Fe2O3 nanourchins are promising candidate for the photocatalytic degradation of various harmful organic dyes and pigments. (C) 2015 Elsevier Inc. All rights reserved.