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以多壁碳纳米管(MWNTs)、氨水(NH_3·H_2O)和九水合硝酸铁[Fe(NO_3)_3·9H_2O]为原料,采用共沉淀法得到前驱体,经高温煅烧制得MWNTs/Fe_2O_3,利用XRD、TEM、UV-Vis和FT-IR等对其结构特性进行分析。以偏二甲肼废水为目标降解物评价了MWNTs/Fe_2O_3的光催化活性,并对光催化机理进行了分析。结果表明,MWNTs的引入可以改变氧化铁(Fe_2O_3)的晶型,同时使Fe_2O_3的粒径减小,并增加催化剂的吸附能力。另外,Fe—O—C化学键的形成使Fe_2O_3和MWNTs之间形成联合电子系统,有利于电子转移,电子-空穴对复合率有效降低。羟基自由基在MWNTs/Fe_2O_3光催化降解偏二甲肼过程中起主要作用。当pH值为7,MWNTs/Fe_2O_3用量为1.0g/L,光催化降解120min,对20mg/L的偏二甲肼的降解率可达98.1%,比相同条件下二氧化钛(TiO_2)的降解率高39.2%。
MWNTs / Fe 2 O 3 were prepared by coprecipitation method using MWNTs, NH 3 · H 2 O and Fe (NO 3) 3 · 9H 2 O as raw materials. The structural characteristics were analyzed by XRD, TEM, UV-Vis and FT-IR. The photocatalytic activity of MWNTs / Fe_2O_3 was evaluated using UDMH wastewater as the target degradation product, and the photocatalytic mechanism was also analyzed. The results show that the introduction of MWNTs can change the crystal form of iron oxide (Fe_2O_3), decrease the particle size of Fe_2O_3 and increase the adsorption capacity of the catalyst. In addition, the formation of Fe-O-C bonds makes the formation of a united electron system between Fe 2 O 3 and MWNTs, which is conducive to electron transfer and effectively reduces the electron-hole recombination rate. Hydroxyl radicals play a major role in the photocatalytic degradation of UDMH by MWNTs / Fe 2 O 3. When the pH value is 7, the amount of MWNTs / Fe_2O_3 is 1.0g / L and the photocatalytic degradation is 120min, the degradation rate of UDMH can reach 98.1% under 20mg / L, which is higher than that of TiO_2 under the same conditions 39.2%.