Hollow cobalt ferrite polyaniline nanofibers (CoFe2O4-PANI) functioning as a photocatalyst were prepared by using electrospinning technique, followed by calcination and in-situ chemical oxidative polymerization. The hollow CoFe2O4-PANI nanofibers with one dimensional (1D) structure provide well developed mesoporous structure and enhanced electrical conductivity. The hollow CoFe2O4-PANI nanofibers consisted of hollow core-double shell nanostructure, which has CoFe2O4 as inner shell and PANI as outer shell. The hollow CoFe2O4-PANI nanofibers coated with PANI nanograins facilitate the optical properties by easily capturing visible light. The intensive visible light absorption and effective charge separation lead to a remarkable improvement of visible light photocatalysis owing to the heterojunction built between CoFe2O4 and PANI. The pseudo-first-order kinetic constant of photo catalytic degradation of the methyl orange (MO) dye under visible light irradiation with CoFe2O4-PANI was 80 times greater than CoFe2O4. This evidence shows the advantage of the unique core shell mesoporous structure in the CoFe2O4-PANI for efficient photocatalysis. The recovery ratio is almost the same after three cycles under visible light irradiation, displaying the excellent characteristics of magnetic separation for CoFe2O4-PANI hollow nanofibers. (C) 2016 Elsevier B.V. All rights reserved.