摘要
采用溶胶-凝胶法制备了Fe3+掺杂TiO2光催化剂。分析表明,制备的Fe3+-TiO2为锐钛矿型,其禁带宽度低于TiO2。将Fe3+-TiO2添加到聚乙烯醇-壳聚糖(PVA-CS)阴离子交换膜中,制备了PVA-CMC/Fe3+-TiO2-PVA-CS双极膜(BPM),(CMC:羧甲基纤维素钠)。研究结果表明,Fe3+-TiO2较TiO2具有更强的光催化双极膜中间界面层水解离能力,在太阳光照射下能大大提高水解离效率,降低双极膜膜阻抗和跨膜电压降。当电流密度为60 mA·cm-2时,PVA-CMC/Fe3+-TiO2-PVA-CS双极膜槽电压下降了0.8 V。此外,通过Fe3+-TiO2改性,CS膜亲水性和双极膜机械性能均获得提高。将改性后的双极膜用于分离模拟海水中一、二价阳离子,在太阳光照射下,K+离子和Na+离子双极膜透过率较无光照时有明显提高,电渗析2 h,K+离子和Na+离子的透过率分别为90.31%和82.93%,而二价阳离子的透过率均小于1.0%。
A Fe^3＋-doped TiO2photocatalyst was prepared through a sol-gel method. X-ray diffraction （XRD） analysis indicates that the prepared Fe^3＋-TiO2 is in anatase phase and the band gap of Fe^3＋-TiO2 is smaller than that of TiO2. Moreover, the prepared Fe^3＋-TiO2 was added into polyvinyl alcohol-chitosan （PVA-CS） anion exchange membrane to prepare PVA-CMC/Fe^3＋-TiOz-PVA-CS bipolar membrane （BPM）, （here, CMC： carboxymethyl cellulose）. Experimental results show that Fe^3＋-TiO2 exhibits better photocatalytic performance for water splitting at the interlayer than that of TiO2. The water splitting efficiency of PVA-CMC/Fe^3＋-TiOz-PVA-CS BPM is improved under sunlight irradiation, and the membrane impedance and trans-membrane voltage drop are obviously decreased. At current density of 60 mA.cm^-2, the cell voltage of a PVA-CMC/Fe^3＋-TiOz-PVA-CS BPM-equipped cell decreases by 0.8 V. Moreover, the hydrophilicity of the CS membrane and the mechanical properties of the BPM are increased after Fe^3＋-TiO2 modification. The PVA-CMC/Fe^3＋-TiOz-PVA-CS BPM was applied to separate monovalent and divalent cations in simulation seawater. The penetration rates of K^＋ and Na^＋ ions through BPM are increased under sunlight irradiation. When electrodialysis time is 2 h, the penetration rates of K^＋ and Na^＋ ions are 90.31% and 82.93% respectively, and the penetration rates of the divalent cations are all smaller than 1%.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2014年第4期731-737,共7页
Journal of Chemical Engineering of Chinese Universities
基金
福建省科技厅重点项目(2012H0019)
福州市科技局项目(2012-G-116)
关键词
双极膜
光催化
水解离
一价
二价阳离子分离
bipolar membrane
photocatalysis
water splitting
separation of monovalent and divalent cations
