Fe@CeO_(2)/CN双空腔核壳磁性载金椭球催化剂及其催化还原对硝基苯酚和染料污染物

Fe@CeO_(2)/CN double-cavity core-shell magnetic Au-loaded ellipsoidal catalysts for catalytic reduction of 4-nitrophenol and dye pollutants

载金催化剂可在温和条件下还原性降解环境中某些有毒有害污染物,并转化为低毒性、高附加值的物质,从而促进水体污染物化学资源转化和综合利用.本文设计制备Fe@CeO_(2)/CN双空腔核壳磁性载金椭球催化剂,用于还原降解水体中对硝基苯酚和染料污染物.该催化剂先制备Fe_(2)O_(3)@CeO_(2)梭型微粒内核,采用乙二胺介导的Stober扩展法在其表面合成SiO_(2)@RF复合物,经过碳化-水热蚀刻得到具有介孔碳氮壳层的Fe_(2)O_(3)@CeO_(2)/CN椭球;采用[Au(en)_(2)]^(3+)为金前驱体的沉积沉淀-还原气氛热处理法在上述椭球中构筑较好分散度超细纳米Au颗粒,同时Fe_(2)O_(3)转化为小体积Fe颗粒并形成内空腔,得到Fe@CeO_(2)-Au/CN双空腔核壳磁性椭球催化剂.该催化剂独特的结构特征和复合组分协同增强性效应使其在还原降解对硝基苯酚和染料污染物中均表现优越的催化反应性能和循环使用性能,重复多次使用后仍保存良好的磁分离性和较好的结构完整性.

Gold-loaded catalysts can degrade some toxic and harmful pollutants in the environment and convert them into substances with lower toxicity and higher added value under mild conditions,thus promoting the conversion and comprehensive utilization of water pollutant chemical resources.This paper provides a novel synthesis strategy to prepare Fe@CeO_(2)/CN double-cavity core-shell magnetic ellipsoids with Au nanoparticles as catalysts for the reductive degradation of 4-nitrophenol and dye pollutants in the aquatic environment.Fe_(2)O_(3)@CeO_(2) shuttle-like particles are prepared as the core of the catalysts, and SiO_(2)@RF composites are synthesized on the surface by the ethylenediamine-mediated Stöber extended method. Fe_(2)O_(3)@CeO_(2)/CN ellipsoids with mesoporous carbon-nitrogen shells are obtained through carbonization and alkaline etching. Using [Au(en)_(2)]^(3+) as gold precursor, ultrafine Au nanoparticles with good dispersion are constructed in the composite ellipsoids by means of deposition-precipitation and reducing atmosphere heat treatment. At the same time, Fe_(2)O_(3) cores are converted into small Fe particles and inner cavities are formed, obtaining Fe@CeO_(2)-Au/CN core-shell magnetic ellipsoidal catalysts with double cavities. The unique structural characteristics of the catalysts and the enhanced synergistic effect of the composite components enable these catalysts to possess excellent catalytic reaction performance and recycling capability in the reductive degradation of 4-nitrophenol and dye pollutants. After repeated use, the catalysts still preserve good magnetic separation ability and original structural integrity.