Fluoride ion accelerating degradation of organic pollutants by Cu(II)-catalyzed Fenton-like reaction at wide pH range.

The degradation of rhodamine B in the F-/Cu(II)/H2O2 system was studied to evaluate the accelerating effect of F- on the Cu(II)-catalyzed Fenton-like reaction. Effects of various parameters, such as F-/Cu2+ ratio, F- and Cu2+ concentrations, initial pH, temperature, H2O2 and rhodamine B concentrations, were investigated. The results confirmed that there is a strong promoting effect of F- on the Cu(II)-catalyzed Fenton-like reaction in a wide pH range of 4-11. In the F-/Cu(II)/H2O2 system the dye could be degraded quickly, and H2O2 had a high utilization. A possible catalytical mechanism was proposed and CuF+ was assumed as the catalytically active species. CuF+ complexed with the OOH- produced by H2O2 dissociation and then rapidly decomposed to Cu(I), which reacted with H2O2 generating hydroxyl radical (HO·), the major reactive oxidizing species.

Catalytic wet peroxide oxidation of azo dye (Direct Blue 15) using solvothermally synthesized copper hydroxide nitrate as catalyst.

Copper hydroxide nitrate (Cu(2)(OH)(3)NO(3)) was synthesized solvothermally in anhydrous ethanol and characterized by XRD, FTIR, TG-DTA and SEM. The peroxide degradation of an azo dye (Direct Blue 15) on this material was evaluated by examining catalyst loading, initial pH, hydrogen peroxide dosage, initial dye concentration and temperature. The leaching of Cu from the copper hydroxide nitrate during the reaction was also measured. The copper hydroxide nitrate synthesized solvothermally, which was of a novel spherical morphology with complex secondary structures and contained high-dispersed Cu(2)O impurity, showed good performance for oxidation degradation of the azo dye, especially high catalytic activity, high utilization of hydrogen peroxide and a wide pH range, whereas the copper hydroxide nitrate synthesized by the direct reaction of copper nitrate and sodium hydroxide showed low catalytic activity.

Copper hydroxyphosphate as catalyst for the wet hydrogen peroxide oxidation of azo dyes.

Copper hydroxyphosphate was synthesized hydrothermally and characterized by XRD and SEM. The peroxide degradation of azo dye on this material was evaluated by examining initial pH, catalyst loading, H(2)O(2) dosage, initial dye concentration and temperature. Although copper hydroxyphosphate is a low surface area material without micropores or mesopores, it shows considerable activity for oxidative degradation of azo dyes under near-neutral pH conditions. A catalyst with such simple and clear structure may be a suitable model material for research on the mechanism of generating hydroxyl radicals and heir destruction of organic molecules.