氮掺杂缺陷TiO_(2)增强光催化净化NO性能  

Enhancement of Photocatalytic Oxidation NO by Nitrogen Doped Defective TiO_(2)

作　　者：郭福荣 周彪 刘旭鹏 邢攀 刘修凡 艾智慧[1] Guo Furong;Zhou Biao;Liu Xupeng;Xing Pan;Liu Xiufan;Ai Zhihui(Key Laboratory of Pesticide&Chemical Biology of Ministry of Education,School of Chemistry,Central China Normal University,Wuhan 430070,China)

机构地区：[1]华中师范大学化学学院农药与化学生物学教育部重点实验室,湖北武汉430074

出　　处：《稀有金属》2023年第1期145-155,共11页Chinese Journal of Rare Metals

基　　金：国家自然科学基金联合基金项目(U20A20129)资助。

摘　　要：半导体光催化技术能利用太阳能有效去除大气低浓度NOx,因而具有广泛应用前景。半导体光催化净化效率依赖于材料的表界面结构,而在氧空位参与的光催化分子氧活化过程中,缺陷氧化物光催化剂会面临氧填充而失活的问题。本文通过溶液-凝胶法合成了氮掺杂缺陷二氧化钛光催化剂(TiO_(2-x-y)N_(y)),TiO_(2-x-y)N_(y)可见光光催化净化低浓度(600×10^(-9))NO的效率高达72%(20 min),而TiO_(2)-x去除NO的效率仅为55%,且TiO_(2-x-y)N_(y)循环后仍能保持70%的NO去除率。光电流和交流阻抗测试结果表明氮的掺杂能够有效提高材料的载流子动力学分离效率。活性物种捕获实验表明能够产生更多的超氧自由基(·O_(2)^(–)),氮掺杂显著增强催化剂活化分子氧的能力。NO-程序升温脱附(NO-TPD),O_(2)^(-)程序升温脱附(O_(2)-TPD),原位电子顺磁共振(in-situ EPR)和差分电荷计算等结果表明TiO_(2-x-y)N_(y)催化剂表面的氧空位位点优先吸附活化O_(2),多电子中心的N能够传递电子修复氧空位,氧空位位点能持续活化分子氧,并捕获空穴促进载流子分离,从而提高TiO_(2)-x-yNy光催化净化NO效率。Semiconductor photocatalytic technology can effectively remove low atmospheric concentration of NOxby using solar ener‐gy,which has a wide application prospect.The purification efficiency of semiconductor photocatalysis depends on the surface interface structure of the material.NOxpurification efficiency can be effectively improved by constructing oxygen vacancy and single atomic structure sites on the surface of the material.While in the photocatalytic oxidation of NO,surface oxygen vacancy can activate O2to form reactive oxygen species (ROS),which can improve the efficiency of NO oxidation to produce nitrate products.However,as the reaction progresses,O2tends to fill the surface oxygen vacancy,resulting in the quenching of the active site and subsequent reduction of catalyst activity.In this paper,nitrogen doped defective titanium dioxide photocatalyst (TiO_(2)-x-yNy) was synthesized by solution-gel method,and the surface oxygen vacancy was repaired by introducing nitrogen element to promote the continuous activation of O2.The photocatalytic performance of TiO_(2)-x-yNywas investigated by simulating the photocatalytic purification of low concentration NO by visi‐ble light.X-ray powder diffraction (XRD) results showed that the crystal phase of TiO_(2)was not changed by the introduction of defects and the doping of nitrogen atoms.X-ray photoelectron spectroscopy (XPS) results showed that the electron cloud density of Ti 2p orbit‐al increased and the characteristic peaks of Ti3+(457.7 eV) and N-Ti bond (400.3 eV) were observed in N 1s spectrum.Electron para‐magnetic resonance (EPR) results confirmed the existence of oxygen vacancies,and the characteristic triple peak of TiO_(2)-x-yNywas at‐tributed to N.In ultraviolet-visible spectroscopy (UV-Vis) diffuse reflectance results,the trailing absorption phenomenon of oxygen va‐cancy appeared in both samples,and the absorption shoulder appeared in TiO_(2)-x-yNydue to the introduction of N.The photocurrent test showed that TiO_(2)-x-yNyhad higher photocurrent

关 键 词：二氧化钛 氧空位(OVS) 氮掺杂 氮氧化物 

分 类 号：X511[环境科学与工程—环境工程]