Hierarchical porous hematite (HPH) network structures were successfully constructed using an improved polymerization induced colloid aggregation process with Fe(NO3)3·9H2O as the raw material.The polymerization between urea and formaldehyde into urea-formaldehyde (UF) resin is the key factor for this construction.The UF resins appear to be advantageous in two respects:the UF oligomer hybrids with ferric hydroxide (Fe-UF) and UF polymer formed microcapsules (UFM) acted as templates to induce the aggregation of Fe-UF hybrids into mesoporous spheres.The further crosslink reactions among the hybrid spheres generate the network structure.After calcination,the decomposition of the UF resin and the UFM produces nanopores in the nanorod subunits and macropores in the network structure,respectively.The photodegradation activity of the unique structured HPH is four times that of the commercial hematite nanoparticles with rhodamine B (RhB) as pollutant.%以九水合硝酸铁为原料,利用改进的聚合诱导胶体聚集(PICA)的方法制备出三维网络状多级孔结构氧化铁(HPH).此结构的制备关键是在合成过程中尿素和甲醛聚合生成脲醛树脂(UF).脲醛树脂一方面在铁的羟基氧化物生长过程中与之杂化形成杂化产物Fe-UF,另一方面则进一步聚合,形成脲醛树脂微球(UFM).脲醛树脂微球作为模板诱导杂化产物Fe-UF在其表面的聚集.微球与微球之间则由于表面存在的脲醛树脂间的聚合会相互交联形成网络状结构.经过煅烧处理后,脲醛树脂及脲醛树脂微球的分解导致不同尺寸孔结构的生成.光催化研究结果表明,产物对罗丹明B的降解效率是商用纳米氧化铁的4倍.
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