Study On Morphology Control And Catalytic Oxidation Performance Of Manganese

In this paper,hollow manganese-containing ferric oxide?Mn-Fe₃O₄?and preferentially oriented manganese dioxide??-MnO₂?nanomaterials were prepared by displacement and hydrothermal methods.The composition and morphology of nanomaterials were characterized by TEM,SEM,XRD and other characterization methods,Congo red and rhodamine B were selected as the target pollutants.The catalytic performance tests of these two types of catalytic materials were carried out,and the reaction conditions were optimized.For hollow manganese-containing ferric oxide,the optimal preparation conditions were as follows:1.5mL 1mol·L^-1FeCl₂ solution was added with 0.08g Mn₃O₄ solution?34ml?,and the reaction was performed in a water bath at 90?for 2 hours to obtain a hollow Mn-Fe₃O₄ nanomaterial.The catalytic material shows good catalytic performance in the experiment of catalyzing the degradation of 100 mL 100 mg·L^-1of hydrogen peroxide with Congo red solution.The best reaction conditions were:the pH value kept 4and the temperature at 25°C and 0.005g of catalyst and 10 mL of hydrogen peroxide.In 20minutes,the removal rate of Congo red solution in the reaction system was above 99%.After the catalytic material was reused in three times,the removal rate under the same conditions was still about 80%.For ?-MnO₂,the optimal preparation conditions were:doping with 1mmoL Co²⁺ions and changing the hydrothermal temperature?172?-181??to prepare the?-MnO₂with the preferred orientation,which was the diffraction peak enhancement corresponding to the?200?crystal plane.The catalytic material shows good catalytic performance in the experiment of catalyzing the degradation of 250 mL of 10 mg·L^-11 rhodamine B solution by hydrogen peroxide.The optimal reaction conditions were:the pH value kept 10 and the temperature at 25°C and 0.003g of catalyst and 10 mL of hydrogen peroxide.In 10minutes,the removal rate of rhodamine B solution in the reaction system was above 99%.After the catalytic material was reused in three times,the removal rate under the same conditions was still about 80%.