Design and preparation of photocatalyst with a visible-light response and high separation efficiency is important for its application in photocatalytic technique. In this presentation, sol-gel method was employed to prepare BiFeO3 photocatalyst using Fe(NO3)(3)center dot 9H(2)O and Bi(NO3)(3)center dot 5H(2)O as the starting materials. Only ethylene glycol (C2H6O2, EG) was used as the solvent and no other surfactants were used. The influences of precursor solution concentration and calcination temperature on the formation of purity and the crystallite size of BiFeO3 were investigated. Well-dispersed BiFeO3 nanoparticles with tunable size and band gap could be synthesized at 500 degrees C. The as-prepared BiFeO3 nanoparticles were used in degradation methyl orange (MO) and MO could be effectively degraded under visible light. (C) 2014 Elsevier Ltd. All rights reserved.