溶剂热合成可见光响应硫氮共掺杂TiO2光催化剂及其催化还原水中Cr(Ⅵ)  

Solvothermal Synthesis of Visible-light Driven S,N Co-doped Titanium DioxidePhotocatalyst and Photocatalytic Reduction of Aqueous Cr(Ⅵ)

作　　者：李靖[1] 刘天宝 朱亚鑫 王鹏[1] 堵锡华[1] 张永才 LI Jing;LIU Tianbao;ZHU Yaxin;WANG Peng;DU Xihua;ZHANG Yongcai(School of Materials and Chemical Engineering,Xuzhou University of Technology,Xuzhou 221111,China;School of Chemistry and Environmental Science,Yili Normal University,Yining 835000,China;School of Chemistry and Chemical Engineering,Yangzhou University,Yangzhou 225002,China)

机构地区：[1]徐州工程学院材料与化学工程学院,徐州221111 [2]伊犁师范大学化学与环境科学学院,伊宁835000 [3]扬州大学化工学院,扬州225002

出　　处：《材料导报》2020年第21期21045-21051,共7页Materials Reports

基　　金：江苏省自然科学基金(BK20171168);江苏省高校自然科学基金重大项目(18KJA430015);江苏省高校青蓝工程优秀青年骨干教师项目(2018)。

摘　　要：分别以硫代乙酰胺和硝酸为硫源和氮源,通过一步溶剂热法制得硫氮共掺杂改性二氧化钛催化剂,并通过XRD、TEM、XPS、UV-vis、N2吸附-脱附和光电流测试硫氮共掺杂二氧化钛(SN-TiO2)的结构、组成和光电性质。结果显示:N和S元素分别以间隙掺杂形成了O-Ti-N键或通过取代晶格结点的Ti4+形成了Ti-O-S键,从而形成新的杂质能级,得到禁带宽度减小、可见光吸收增强、载流子迁移速率加快的锐钛矿相SN-TiO2纳米粉。以Cr(Ⅵ)为模拟污染物,评估了A-SN-TiO2的可见光催化性能,并将其与硫脲为硫源制备的B-SN-TiO2、S-TiO2、N-TiO2和TiO2的光催化活性进行了对比。光催化和ESR测试结果显示,A-SN-TiO2具有更高的催化活性,在光照60 min后,A2-SN-TiO2对Cr(Ⅵ)的还原率高达100%。此外,研究还发现SN-TiO2可见光催化还原Cr(Ⅵ)的主要活性物质为·O2-。An unique one-step solvothermal route,which utilized thioacetamide and nitric acid as the sulphur and nitrogen source,was proposed for the synthesis of S-N co-doped TiO2 nanocrystals.The structures,composition,BET specific surface area and optical properties of SN-TiO2 were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,UV-vis diffuse reflectance spectroscopy,N2 adsorption-desorption isotherms and photocurrent measure.It’s demonstrated that anatase phase SN-TiO2 nanopowders with enhanced visible-light absorption,reduced bandgap and fast mobility of photogenerated carriers,and Ti4+was substituted in the TiO2 lattice by cationic S6+and formed a new bond of Ti-O-S,and interstitially doped nitrogen atoms induced the formation of O-Ti-N bonds.The photocatalytic properties of A-SN-TiO2 were tested for the reduction of Cr(Ⅵ) in water under both UV and visible light (λ>420 nm) irradiation in the absence of any sacrificial reagents,and compared with those of TiO2,S-TiO2,N-TiO2 and B-SN-TiO2 prepared with thiourea.The photocatalytic experiments indicated that A-SN-TiO2 exhibit the highest photoreduction efficiency,and noticeably the photocatalytic reduction rate of Cr(Ⅵ) of A2-SN-TiO2 was 100%under visible light irradiation after 60 min.Active species capture experiments and ESR showed that·O2- is the active radicals in the photocatalysis.Photocatalytic mechanism of A-SN-TiO2 reduction of Cr(Ⅵ) was revealed based on the experimental results.

关 键 词：共掺杂 二氧化钛 可见光响应 六价铬 光催化 

分 类 号：O611[理学—无机化学]