Preparation And Characterization Of Recycled Nano Adsorption Catalysis Material Coal Gangue/Fe₃O₄@TiO₂

In recent years, the problem of coal gangue accumulation pollution has become the hot spot that It is concerned by more and more researchers. Because of its excellent photocatalytic properties,the TiO₂ has also been concerned.But It is difficult to recover the TiO₂ after the pollutant are degraded by the TiO₂.in view of these two points, we design and prepare coal gangue/Fe₃O₄@TiO₂,which is a recyclable nano material with function of adsorption and catalysis,It not only solve the problem of coal gangue accumulation,but also solve the problem of TiO₂ is difficult to recover,shoot two hawks with one arrow.（1） in this paper,the coal gangue was modified by NaOH solution、 NaOH solid and ZnCl₂ solid,and the methyl orange solution was used to simulate dye wastewater to test adsorption performance of modified coal gangue, the optimum conditions of using these three methods to modify coal gangue were obtained. The optimum conditions of using NaOH solution to modify coal gangue were concentration of NaOH solution was 2mol/L,under the liquid-solid ratio of 10mL/g,calcination temperature of 600℃,calcination time of 2.5h. The optimum conditions of using NaOH solid to modify coal gangue were coal gangue and NaOH solid mass ratio of 2.5:1,calcination temperature of 700℃,calcination time of 2h.The optimum conditions of using ZnCl₂ solid to modify coal gangue were ZnCl₂ solid and coal gangue mass ratio of 0.7:1, calcination temperature of 550℃, calcination time of 3h.The results showed that the coal gangue of the optimum adsorption performance was modified by ZnCl₂ solid, the adsorption capacity of modified coal gangue could reach 14.12mg/g after the adsorption of12 h.（2） The modified coal gangue/Fe₃O₄ composites was prepared by coprecipitation method, the effect of modified coal gangue and Fe₃O₄ mass ratio on the adsorption performance and magnetism of composites was studied.Drawing the conclusion:when the mass ratio of modified coal gangue and Fe₃O₄ was 1:1,the performance of composites was best,the adsorption capacity of the composites could reach 9.84mg/g after the adsorption of 6h,the saturated magnetization of composites is 81.44emu/g and could be achieved the magnetic recycling.（3） The Fe₃O₄/TiO₂ composites was prepared by sol-gel method, the photocatalytic degradation performance of composite be tested by Rhodamine B solution.The effect of Fe₃O₄ and TiO₂ mass ratio on photocatalytic degradation performance and magnetism of composites was studied. Drawing the conclusion: when the mass ratio of Fe₃O₄ and TiO₂ was 1:3.5,the performance of composites was best, the degradation rate of The Fe₃O₄/TiO₂ composites on Rhodamine B reached 95.41% after the photocatalytic degradation of 2.5h,the saturated magnetization of composites is 38.15emu/g and could be achieved the magnetic recycling.（4） The modified coal gangue/Fe₃O₄@TiO₂ composites was prepared by sol-gel method, the photocatalytic degradation performance of composites be tested by Rhodamine B solution.Drawing the conclusion: when the mass ratio of modified coal gangue、 Fe₃O₄ and TiO₂ was1:2:4,the photocatalytic degradation performance of composites on Rhodamine B was superior to pure TiO₂ and compared with pure TiO₂,the use of TiO₂ in the composites to be reduced by 43%, the saturated magnetization of composites is 35.23emu/g and could also meet the requirements of magnetic recycling.