物理化学学报
物理化學學報
물이화학학보
ACTA PHYSICO-CHIMICA SINICA
2013年
6期
1327-1335
,共9页
杨汉培*%张颖超%傅小飞%宋双双%吴俊明
楊漢培*%張穎超%傅小飛%宋雙雙%吳俊明
양한배*%장영초%부소비%송쌍쌍%오준명
碳纳米管%表面修饰%溶解性能%TiO2%光催化降解
碳納米管%錶麵脩飾%溶解性能%TiO2%光催化降解
탄납미관%표면수식%용해성능%TiO2%광최화강해
Carbon nanotubes%Surface modification%Solubility%TiO2%Photocatalytic degradation
碳纳米管(CNTs)混酸(H2SO4/HNO3,体积比为3:1)超声辅助纯化及氧化植入活性基团-COOH,进一步借助其转化为酰氯基团,分别于CNTs表面共价嫁接亲水性赖氨酸及亲脂性正十八胺基团,赋予赖氨酸表面改性CNTs显著水溶(6.85 mg·mL-1)和十八胺表面改性CNTs显著醇溶(10.15 mg·mL-1)性能.运用低温水热法以亲水性CNTs复合TiO2,溶胶-凝胶法以亲脂性CNTs复合TiO2,观察到复合催化剂光催化性能随 CNTs溶剂分散性能增加而明显提升.运用傅里叶变换红外(FTIR)、激光拉曼、X射线衍射(XRD)、Brunauer-Emmett-Tel er低温氮气吸附、透射电镜(TEM)及X光电子能谱(XPS)等手段表征,系统探讨CNTs的表面改性机制及CNTs溶解分散性能与复合催化剂的光活性的关联.认为表面改性CNTs借助Ti-O-C键合促进其与纳米TiO2的异质结合,从而充分利用CNTs的大比表面积及电荷传输性能促进催化剂的污染物光催化降解.
碳納米管(CNTs)混痠(H2SO4/HNO3,體積比為3:1)超聲輔助純化及氧化植入活性基糰-COOH,進一步藉助其轉化為酰氯基糰,分彆于CNTs錶麵共價嫁接親水性賴氨痠及親脂性正十八胺基糰,賦予賴氨痠錶麵改性CNTs顯著水溶(6.85 mg·mL-1)和十八胺錶麵改性CNTs顯著醇溶(10.15 mg·mL-1)性能.運用低溫水熱法以親水性CNTs複閤TiO2,溶膠-凝膠法以親脂性CNTs複閤TiO2,觀察到複閤催化劑光催化性能隨 CNTs溶劑分散性能增加而明顯提升.運用傅裏葉變換紅外(FTIR)、激光拉曼、X射線衍射(XRD)、Brunauer-Emmett-Tel er低溫氮氣吸附、透射電鏡(TEM)及X光電子能譜(XPS)等手段錶徵,繫統探討CNTs的錶麵改性機製及CNTs溶解分散性能與複閤催化劑的光活性的關聯.認為錶麵改性CNTs藉助Ti-O-C鍵閤促進其與納米TiO2的異質結閤,從而充分利用CNTs的大比錶麵積及電荷傳輸性能促進催化劑的汙染物光催化降解.
탄납미관(CNTs)혼산(H2SO4/HNO3,체적비위3:1)초성보조순화급양화식입활성기단-COOH,진일보차조기전화위선록기단,분별우CNTs표면공개가접친수성뢰안산급친지성정십팔알기단,부여뢰안산표면개성CNTs현저수용(6.85 mg·mL-1)화십팔알표면개성CNTs현저순용(10.15 mg·mL-1)성능.운용저온수열법이친수성CNTs복합TiO2,용효-응효법이친지성CNTs복합TiO2,관찰도복합최화제광최화성능수 CNTs용제분산성능증가이명현제승.운용부리협변환홍외(FTIR)、격광랍만、X사선연사(XRD)、Brunauer-Emmett-Tel er저온담기흡부、투사전경(TEM)급X광전자능보(XPS)등수단표정,계통탐토CNTs적표면개성궤제급CNTs용해분산성능여복합최화제적광활성적관련.인위표면개성CNTs차조Ti-O-C건합촉진기여납미TiO2적이질결합,종이충분이용CNTs적대비표면적급전하전수성능촉진최화제적오염물광최화강해.
@@@@Carbon nanotubes (CNTs) have been ultrasonically treated with the mixed acid (H2SO4/HNO3, 3:1, volume ratio), embedding the active -COOH groups onto the surface of the CNTs. As a result, the acid-treated CNTs serve as chemical reactors for subsequent grafting of L-lysine or octadecylamine (ODA). It was revealed that L-lysine and ODA covalently bond to the surface of the oxidized CNTs through amidation of carboxylic acid groups (CNTs-COOH) and lysine or ODA via intermediate acyl chlorides (CNTs-COCl). The hydrophilic and lipophilic CNTs have high aquatic and ethanol solubility, and the solubility of the surface modified CNTs in water and ethanol were measured to be as high as 6.85 and 10.15 mg·mL-1, respectively. The surface nature of modified CNTs and the properties of TiO2-CNTs composite photocatalysts, which were prepared through sol-gel or low temperature hydrothermal synthesis, were investigated by Fourier transform infrared (FTIR), laser Raman, X-ray diffraction (XRD), Brunauer-Emmett-Tel er N2 adsorption, transmission electron microscopy (TEM), and X-ray photoelectron spectrum (XPS). Improved photocatalytic performance was observed for TiO2 coupled by hydrophilic or lipophilic CNT, which were obtained by low temperature hydrothermal and sol-gel synthesis, respectively, and it was revealed that there is an affinity between the photocatalytic performance of TiO2-CNTs hybrids and the dispersibility of CNTs. It is proposed that the improved photocatalytic activity of CNT-TiO2 compared with pure TiO2 photocatalysts can be mainly attributed to the homogeneous and dense dispersion of TiO2 on the modified CNTs and the intimate contact between TiO2 and CNTs, which results in dense heterojunctions at the interface of TiO2 and CNTs through the Ti-O-C structure.
