纳米α-Fe_2O_3-TiO_2改性海藻酸钠/壳聚糖双极膜制备与表征

Preparation and Characterization of Bipolar Membrane Modified by Nano-α-Fe_2O_3-TiO_2

在壳聚糖(CS)阴离子交换膜中添加纳米复合半导体材料α-Fe2O3-TiO2,制备了PVA-SA/α-Fe2O3-TiO2-CS双极膜(PVA:聚乙烯醇;SA:海藻酸钠),并用扫描电镜、热重分析、电子万能试验机和接触角测定仪等对其进行了表征。研究结果表明,添加纳米α-Fe2O3-TiO2可提高双极膜的亲水性、热稳定性和机械性能。纳米α-Fe2O3-TiO2复合半导体材料较纳米α-Fe2O3或纳米TiO2单一半导体材料具有更强的光催化双极膜中间界面层水解离能力,在高压汞灯照射下能大大降低双极膜的膜阻抗和膜电阻压降(IR降)。

The nano-α-Fe2O3 and nano-TiO2 were added into chitosan（CS） anion layer to prepare the PVA-SA/αFe2O3-TiO2-CS（Here,PVA：polyvinyl alcohol;SA：sodium alginate） bipolar membrane（BPM）,which was characterized using SEM,TGA,electric universal testing machine,contact angle measurer and so on.Experimental results showed that nano-α-Fe2O3-TiO2had better photocatalytic property for water splitting in the interlayer of BPM than nano-α-Fe2O3 or nano-TiO2.Under the irradiation of high-pressure mercury lamps,the membrane impedance and IR drop of the BPM modified by nano-α-Fe2O3-TiO2 were evidently decreased.At a current density of 60 mA·cm-2,the cell voltage of PVA-SA/α-Fe2O3-TiO2-CS BPM decreased by 1.2 V.And the cell voltages of PVA-SA/αFe2O3-CS BPM and PVA-SA/TiO2-CS BPM were reduced by 0.2 V and 0.7 V,respectively.Moreover,the hydrophilicity,thermal stability and mechanical properties of the modified BPM were increased.