等离子体氟改性TiO_(2)催化剂的制备及其光催化性能  

Preparation of Fluorine Modified Titanium Dioxide Catalyst and Its Photocatalytic Degradation for Oilfield Wastewater

作　　者：周立臣 ZHOU Lichen(Zhanjiang Branch of CNOOC(China)Co.,Ltd.,Zhanjiang 524000,China)

机构地区：[1]中海石油(中国)有限公司湛江分公司,湛江524000

出　　处：《材料研究学报》2024年第2期141-150,共10页Chinese Journal of Materials Research

基　　金：国家重点研发计划(2019YFA0708302)。

摘　　要：以C_(2)H_(2)F_(4)为F源,用等离子体放电对TiO_(2)实现F改性制备TiO_(2)催化剂,并使用XRD、XPS、UV-vis、PL等手段表征其形貌和结构。以亚甲基蓝和油田废水作为污染物,研究外部环境对催化剂降解性能的影响和重复使用性能,并使用自由基清除剂揭示其光催化机理。结果表明,催化剂添加量为8 g/L、pH值为6时,其对油田废水的降解效果最佳化学需氧量(COD)的去除率可达88%。同时,环境中的HCO_(3)^(-)、CO_(3)^(2-)、PO_(4)^(3-)、SiO_(3)2-能显著抑制光催化反应,而Cl^(-)的影响不大。羟基自由基(·OH)对光催化反应的影响更为关键。等离子体氟改性后,二氧化钛表面产生大量的≡Ti-F键和氧缺陷,实现了TiO_(2)的间隙F掺杂(Ti-O-F-Ti键),≡Ti-F和氧缺陷促进了光生电子-空穴向TiO_(2)表面转移。同时,间隙F掺杂在TiO_(2)价带上方产生杂质能级,使禁带宽度从2.98 eV收窄到2.82 eV,增强了这种催化剂在可见光区域的吸收,提高了其对油田废水的光催化降解效率。The florine modification of titanium dioxide was realized by plasma discharge technique with C_(2)H_(2)F_(4) as F source,and the morphology and structure of the catalyst were characterized by XRD,XPS,UV-vis,PL,etc.The effectiveness of fluorine-modified titanium dioxide catalyst was studied in terms of the degradation of methylene blue and oilfield wastewater,and the corresponding influencing factors as well as the reusability of the catalyst were investigated.The results showed that for the corrosive medium of pH 6 with the addition of 8 g/L catalyst,the best degradation effect on oilfield wastewater was acquired with the COD removal rate up to 88%.For the corrosive medium with the presence of HCO_(3)^(-),CO_(2)^(3-),PO_(3)^(4-),and SiO_(2)^(3-),the photocatalytic induced reaction would be significantly inhibited,while Cl-had little effect on it.Besides,the hydroxyl radical(·OH)was more critical for the photocatalytic related reaction.It follows that after plasma induced fluorine modification,a large number of≡Ti-F bond and oxygen defects could be produced on the surface of titanium dioxide,achieving fluorine dopped TiO_(2) gaps(Ti-OF-Ti bond),in turn,the≡Ti-F and oxygen defects can promote the transfer of photogenerated electronholes to the surface of titanium dioxide,meanwhile,the fluorine dopped TiO_(2) gaps caused a hybrid valence band of titanium dioxide,consequently narrowing the band gap width from 2.98 eV to 2.82 eV,which can enhance the absorption of the catalyst in the visible light region and improve the photocatalytic degradation efficiency of oilfield wastewater.

关 键 词：无机非金属材料 工业催化 油田废水 等离子体 TiO_(2)光催化 

分 类 号：O649.4[理学—物理化学]