In-situ one-step synthesis of novel BiOCl/Bi24O31Cl10 heterojunctions via self-combustion of ionic liquid with enhanced visible-light photocatalytic activities

A facile and fast method was developed for the preparation of novel BiOCl/Bi24O31Cl10 heterojunctions via a self-combustion of ionic liquids (ILs) route. The ILs were prepared from Bi(NO3)(3)center dot 5H(2)O and diethylamine hydrochloride ((C2H5)(2)NH center dot HCl). The photocatalysts were obtained by heating the ILs to combustion. In the ILs system, (C2H5)2NH center dot HCl serves not only as the source of cation in IL, but also as the main fuel. The prepared composites exhibit noticeable visible light photocatalytic activity in the degradation of organic pollutants, including anionic dye methyl orange and cationic dye rhodamine B, which is attributed to the narrow band gap (2.3 eV) and the effective electrons transfer from the conductive band of Bi24O31Cl10 to that of BiOCl, improving the separation efficiency of the photo-generated electron/hole pairs. The heterojunction containing 60.4% BiOCl and 39.6% Bi24O31Cl10 exhibits the highest photocatalytic activity. The heterojunction shows dramatic adsorption performance for cationic dye rhodamine B because of its surface negative charges. The radical scavengers result shows that hole is the main reactive species responsible for the degradation of pollutants and superoxide radials are also involved in the photocatalytic process. The results obtained may provide a new sight for broadening the application of ILs in the preparation of nanomaterials and for the in-situ one-step synthesis of heterostructural materials. (C) 2014 Elsevier B.V. All rights reserved.