Bi_(2)Ti_(2)O_(7)/TiO_(2)/Bi_(4)Ti_(3)O_(12)多异质结的构筑及其增强的可见光催化性能  

Fabrication of Bi_(2)Ti_(2)O_(7)/TiO_(2)/Bi_(4)Ti_(3)O_(12) multi-heterojunction and the enhanced visible photocatalytic performance

作　　者：曹铁平[1] 李跃军[1] 孙大伟 CAO Tie‑Ping;LI Yue‑Jun;SUN Da‑Wei(Research Centre of Nano-photocatalyst,Baicheng Normal University,Baicheng,Jilin 137000,China)

机构地区：[1]白城师范学院,纳米光催化材料研究中心,白城137000

出　　处：《无机化学学报》2023年第4期699-708,共10页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.21573003);国家级大学生创新创业训练计划项目(No.201810206003)资助。

摘　　要：以静电纺丝技术制备的TiO_(2)纳米纤维为基质,硝酸铋为铋源,KOH为矿化剂,成功制备了多异质结Bi_(2)Ti_(2)O_(7)/TiO_(2)/Bi_(4)Ti_(3)O_(12)复合纳米纤维光催化剂。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外可见漫反射光谱(UV-Vis DRS)等一系列表征,对其物相组成、微观形貌和光学性质等进行分析。结果表明:TiO_(2)纳米纤维的介入,将Ⅰ型异质结Bi_(2)Ti_(2)O_(7)/Bi_(4)Ti_(3)O_(12)分离为2个Ⅱ型异质结Bi_(2)Ti_(2)O_(7)/TiO_(2)和Bi_(4)Ti_(3)O_(12)/TiO_(2)。Bi_(2)Ti_(2)O_(7)、Bi_(4)Ti_(3)O_(12)和TiO_(2)三者的协同作用,有效提高了可见光吸收能力,改变了光生载流子的传输路径,降低了光生电子与空穴的复合几率,从而获得高效的光催化降解CH_(3)CHO性能。可见光照8 h,Bi_(4)Ti_(3)O_(12)/TiO_(2)/Bi_(2)Ti_(2)O_(7)复合纳米纤维对CH_(3)CHO的降解率达到87.1%。In this work,we prepared double heterojunction Bi_(2)Ti_(2)O_(7)/TiO_(2)/Bi_(4)Ti_(3)O_(12) composite nanofibers by employing electrospun TiO_(2) nanofibers as the substrate,bismuth nitrate as the bismuth source,and potassium hydroxide as the mineralizing agent.Through a series of tests such as X‑ray diffraction(XRD),scanning electron microscope(SEM),UV‑visible diffuse reflectance spectrum(UV‑Vis DRS),the phase composition,micromorphology,and optical properties of the Bi_(2)Ti_(2)O_(7)/TiO_(2)/Bi_(4)Ti_(3)O_(12) catalyst were analyzed.The results showed that the TiO_(2) changed typeⅠheterojunction into multi‑heterojunction integrating two typeⅡheterojunctions.Photocatalytic tests demonstrated the activity of as‑constructed multi‑heterojunction was higher than that of single typeⅠorⅡheterojunctions,respectively,where photogenerated electrons were accumulated on the surface of TiO_(2) and photogenerated holes were accumulated on Bi_(2)Ti_(2)O_(7) and Bi_(4)Ti_(3)O_(12),respectively.The synergistic effect of Bi_(2)Ti_(2)O_(7),Bi_(4)Ti_(3)O_(12),and TiO_(2) effectively improves the visible light absorption capacity,changes the transmission path of photo‑generated carriers,and reduces the recombination probability of photogenerated electron‑hole pairs,thereby obtaining the efficient photocatalytic degradation of CH_(3)CHO.The acetaldehyde degradation rate of Bi_(2)Ti_(2)O_(7)/TiO_(2)/Bi_(4)Ti_(3)O_(12) reached 87.1%under visible light illumination for 8 h.

关 键 词：TiO_(2)纳米纤维 多异质结 光催化 水热法 

分 类 号：O614.32[理学—无机化学]