Facile synthesis of α-Fe2O3 nanodisk with superior photocatalytic performance and mechanism insight

Abstract

Intrinsic short hole diffusion length is a well-known problem for α-Fe<inf>2</inf>O<inf>3</inf> as a visible-light photocatalytic material. In this paper, a nanodisk morphology was designed to remarkably enhance separation of electron-hole pairs of α-Fe<inf>2</inf>O<inf>3</inf>. As expected, α-Fe<inf>2</inf>O<inf>3</inf> nanodisks presented superior photocatalytic activity toward methylene blue degradation: more than 90% of the dye could be photodegraded within 30 min in comparison with a degradation efficiency of 50% for conventional Fe<inf>2</inf>O<inf>3</inf> powder. The unique multilayer structure is thought to play a key role in the remarkably improved photocatalytic performance. Further experiments involving mechanism investigations revealed that instead of high surface area, ·OH plays a crucial role in methylene blue degradation and that O^.2- may also contribute effectively to the degradation process. This paper demonstrates a facile and energy-saving route to fabricating homogenous α-Fe<inf>2</inf>O<inf>3</inf> nanodisks with superior photocatalytic activity that is suitable for the treatment of contaminated water and that meets the requirement of mass production.