Synthesis and photocatalytic activity of nano-cobalt ferrite catalyst for the photo-degradation various dyes under simulated sunlight irradiation

Abstract

A series of nano-CoFe2O4 photocatalysts were synthesized by a microwave assisted wet chemistry method on the basis of oxalic acid as a chelating agent and N, N′-methylene-bisacrylamide as a cross-links agent without adding glucose. XRD results indicate that the CoFe2O4 precursor powders calcined at 500 ℃ has a good crystallization. Nitrogen adsorption experiment indicates that the specific surface area of nano-CoFe2O4 photocatalysts decreases with the increasing calcining temperature. The surface morphology of the CoFe2O4 nanoparticles varies with pH value. The photocatalytic activity of the nano-CoFe2O4 photocatalyst for the degradation of congo red (CR), methy orange (MO), methylene blue (MB), Rhodamine B (RhB), 4-nitrophenol (4-N), 4-chlorophenol (4-C) under simulated sunlight irradiation have been systematically studied. The nano-CoFe2O4 photocatalyst shows a higher photocatalytic activity for degradation of the CR and MO dyes than degradation of other four dyes due to the nano-CoFe2O4 photocatalyst preferentially degradation the -N = N- bonds of dye molecule. The photo-degradation rate of the nano-CoFe2O4 catalysts increases with the increasing specific surface area. Photocatalytic degradation experiment results also reveal that the nano-CoFe2O4 photocatalyst exhibits an enhanced photocatalytic degradation activity for the degradation of the MB, RhB, 4-N, 4-C dyes discoloration with H2O2. The photocatalytic mechanism analysis found that the H2O2 easy decomposition into hydroxyl radicals to produce the peroxide radical.