N,Fe共掺杂TiO_2纳米材料的固相合成及其对喹啉的可见光降解

Synthesis of N,Fe Co-doped TiO_2 Nanomaterials via Solid State Reaction and Their Photodegradation of Quinoline Irradiated under Visible Light

采用固相反应法分别合成了铁掺杂二氧化钛(Fe-TiO2)及氮和铁共掺杂二氧化钛(N-Fe-TiO2)纳米材料.并对材料进行了XRD、SEM、UV-Vis、XPS、AAS及全自动元素分析等技术的物相织构及元素组成表征,同时研究了催化剂对喹啉的可见光降解性能.结果表明,在球形的N-Fe-TiO2纳米材料中,N以阴离子(N3-)进入二氧化钛晶格,Fe3+以同晶取代方式占据TiO2晶格中Ti的位置,紫外-可见漫反射吸收光谱红移到600nm.N/Fe投料比的增大有助于N-Fe-TiO2催化剂晶型的转化.在25℃、pH=6.5下,所制得的光催化材料对喹啉的可见光降解行为均具有较高的光催化活性,并服从一级反应动力学规律,而纯TiO2对喹啉不降解.N-Fe-TiO2(n(N2H4.H2O):n(FeCl3.6H2O)=1:9)催化剂对喹啉的可见光降解速率常数比Fe-TiO2大.

Fe-doped TiO2（Fe-TiO2）and N,Fe co-doped TiO2（N-Fe-TiO2）nanomaterials were synthesized by solid-state reaction,respectively.The textural properties of the samples were characterized by X-ray diffraction（XRD）,scanning electron microscope（SEM）,ultraviolet visible light spectroscope（UV-Vis）,X-ray photoelectron spectroscope（XPS）.The components of the samples were determined by atomic absorption spectrum（AAS）and automatic elemental analyzer.Moreover,the photodegradation properties of quinoline irradiated under visible light on the materials were investigated.The results show that N atoms as N3-states are incorporated into the lattice of TiO2,and Fe3＋ ions occupy the sites of Ti4＋ by isomorphous replacement in the spheric shape N-Fe-TiO2 nanomaterials.The UV-Vis absorption onset of the N-Fe-TiO2 samples extends well into the visible region at 600 nm.Furthermore,an increase of the initial ratio of N2H4.H2O to FeCl3.6H2O enhances the phase transformation of N-Fe-TiO2 catalysts.At 25℃,pH=6.5,the rule of pseudo-first-order reaction and excellent photocatalytic activity on the N-Fe-TiO2 catalysts are found in the process of photodegradation of quinoline.However,quinoline can not be degradated by pure TiO2 under visible light irradiation.The reaction rate constant of N-Fe-TiO2（n（N2H4.H2O）：n（FeCl3.6H2O）=1：9）catalyst is higher than that of pure TiO2 powder.