催化学报 ›› 2018, Vol. 39 ›› Issue (4): 747-759.DOI: 10.1016/S1872-2067(18)63038-4

• 论文 • 上一篇    下一篇

通过一种新型共前驱体的方法简单合成能增强TiO2可见光光催化活性的C修饰及Fe,N共掺杂的TiO2材料

蒋华麟a,b, 刘军a,b, 厉梦琳a,b, 田磊a,b, 丁攻圣b, 陈萍华a,b, 罗旭彪a,b   

  1. a 江西省持久性污染物控制和资源循环利用重点实验室, 江西南昌 330063;
    b 南昌航空大学环境与化学工程学院, 江西南昌 330063
  • 收稿日期:2017-12-24 修回日期:2018-01-18 出版日期:2018-04-18 发布日期:2018-04-08
  • 通讯作者: 陈萍华, 罗旭彪
  • 基金资助:

    国家自然科学基金(51368044,51568051,51668046);国家优秀青年基金(51422807);江西省科技支持计划(20151BBG70018);江西省杰出青年学者自然科学基金(20162BCB23041);江西省青年科学基金重点项目(20171ACB21034);江西省教育部科技项目(GJJ160700);江西省自然科学基金(20161BAB216102);江西省教育改革项目(JXJG-16-8-7);南昌航空大学教育改革项目(JY1604,JY1605KCPY-1511).

Facile synthesis of C-decorated Fe, N co-doped TiO2 with enhanced visible-light photocatalytic activity by a novel co-precursor method

Hualin Jianga,b, Jun Liua,b, Menglin Lia,b, Lei Tiana,b, Gongsheng Dingb, Pinghua Chena,b, Xubiao Luoa,b   

  1. a Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang 330063, Jiangxi, China;
    b College of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063, Jiangxi, China
  • Received:2017-12-24 Revised:2018-01-18 Online:2018-04-18 Published:2018-04-08
  • Contact: 10.1016/S1872-2067(18)63038-4
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (51368044, 51568051, 51668046), the National Science Fund for Excellent Young Scholars (51422807), the Science and Technology Supporting Program of Jiangxi Province (20151BBG70018), the Natural Science Foundation of Jiangxi Province for Distinguished Young Scholars (20162BCB23041), the Science Foundation for Young Scientists of Jiangxi Province-Key Project (20171ACB21034), the Science and Technology Project of Jiangxi Provincial Education Department (GJJ160700), the Natural Science Foundation of Jiangxi Province (20161BAB216102), the Jiangxi Province Educational Reform Project (JXJG-16-8-7), and the Nanchang Hangkong University Educational Reform Project (JY1604, JY1605, KCPY-1511).

摘要:

为了提高TiO2的可见光光催化活性,研究者做了很多努力.晶格掺杂和表面修饰是提高TiO2可见光光催化活性的两种重要方法,但由于这两种方法实施的条件不一样,所以很难将它们在同一个制备过程中统一起来.为了解决这个问题,我们通过邻菲罗啉与Fe2+络合形成Fe(Ⅱ)-phenanthroline配合物,然后以这种配合物作为Fe,N,C的共同来源,通过水热-煅烧的方法合成Fe,N共掺杂且C表面修饰的TiO2材料(Fe,N co-doped TiO2/C).通过其在可见光照射下降解4-NP来评估材料的性能,同时也以XRD,FT-IR,XPS,EPR等手段对材料进行表征,结合实验结果推测了其可能的光催化机理.由可见光光催化降解动力学数据可知,Fe,N co-doped TiO2/C表现出来的性能最佳,其反应速率常数为0.00963min-1,约是纯TiO2的5.9倍,约是以三种单独来源分别引入Fe,N,C三种元素样品((Fe,N,C)-TiO2)的5.1倍.这说明不同引入元素之间的强烈相互作用可以协同地提高TiO2光催化能力.HRTEM图片显示Fe,N co-doped TiO2/C中存在异质结结构,它是锐钛矿和板钛矿的混合晶相,TiO2的这种混合晶型有利于增强其光催化性能.结合Fe,N co-doped TiO2/C的XPS、拉曼和FT-IR数据进行分析,结果显示C元素是修饰在TiO2晶体表面,N元素是完全掺杂到TiO2晶格中,Fe元素大部分掺杂到晶格中,少部分修饰在晶体表面(这在Fe掺杂TiO2的研究中较常见).另外,从XPS元素相对含量分析可知,用邻菲罗啉作为C,N的共同来源同时引入C,N,引入量比以往的报道提高了2倍左右,这表明我们报道的这种方法可以高水平地同时向TiO2引入C和N元素,为同时高水平地向TiO2中引入这两种元素提供了新的思路.结合EPR,时间-电流图,电化学阻抗图谱(EIS),光致发光图谱,Mott-Schottky图谱,XPS导带分析,活性自由基中间体捕获实验等多种表征的结果,我们推测Fe,N co-doped TiO2/C的光催化机理如下:在可见光照射下,Fe,N co-doped TiO2/C被激发而产生电子与空穴(h+),电子与氧气反应形成O2·-,然后O2·-和h+把污染物分子氧化并降解它们,而材料表面所修饰的C物质受之前所转移过来电子的保护,而不至于被强烈氧化.本研究实现了TiO2晶格掺杂与表面修饰在同一制备过程的结合,为制备高性能无机-有机元素共掺杂,内部-外部共改性的TiO2光催化材料提供了新的思路.

关键词: 晶格掺杂, 表面修饰, TiO2, 光催化, 降解4-NP

Abstract:

Lattice-doping and surface decoration are prospective routes to improve the visible-light photocatalytic ability of TiO2, but the two techniques are difficult to combine into one preparation process because they are usually conducted under different conditions, which limits the efficiency of TiO2 modification. In this study, TiO2 was successfully modified by simultaneous lattice-doping and surface decoration, and the visible-light photocatalytic capacity was largely improved. Upon comparing the method reported here with previous ones, the most significant difference is that Fe(Ⅱ)-phenanthroline was first used as the co-precursor of the introduced elements of C, N, and Fe. These three elements were simultaneously introduced to TiO2 at high levels by this co-precursor method. The as-synthesized photocatalysts were systemically investigated and analyzed by several characterization methods such as XRD, FT-IR, XPS, Raman spectroscopy, EPR, UV-Vis DRS, photoluminescence spectra, photocurrent, electrochemical impedance spectra, TEM, and HRTEM. The photocatalytic degradation of 4-NP under visible-light irradiation was used to evaluate the photocatalytic activity of the photocatalysts. Based on the experimental data, a probable mechanism for the photocatalytic degradation by the photocatalysts is proposed. This is a novel method of using one source to simultaneously introduce metal and non-metal elements to TiO2 at high levels, which may provide a new way to prepare highly effective TiO2 photocatalysts.

Key words: Lattice doping, Surface decoration, TiO2, Photocatalysis, 4-nitrophenol removal