接枝聚合聚苯胺/CeO2-COOH复合材料的性能及聚合机制

Graft Polymerization Mechanism and Properties of Polyaniline/CeO2-COOH Composites

对二氧化铈(CeO2)进行羧基化改性得到羧基化二氧化铈(CeO2-COOH),并与苯胺(An)接枝聚合得到核壳结构聚苯胺/二氧化铈复合材料(PANI/CeO2-COOH)。采用红外光谱、X射线光电子能谱、X射线衍射、热重分析、扫描电子显微镜及旋转圆盘电化学测试技术分析材料的结构及性能。结果表明,CeO2-COOH的CeIII/CeIV的比值接近1,具有较高的表面氧空位;PANI/CeO2-COOH中PANI接枝效果较好,而且与纯PANI结构相同;CeO2-COOH与PANI之间通过价键接枝形成的PANI/CeO2-COOH复合材料起始分解温度在228℃左右,且在200~600℃内的分解速率较慢,表现出较好的热稳定性;在1mol/LH2SO4中对电极进行循环伏安和恒电流充放电测试,PANI/CeO2-COOH复合材料电极不仅具有良好的峰对称性和最高阳极峰电流,而且还具有较好的电容性能,当电流密度为0.5A/g时,比电容达到149.5F/g。

Cerium dioxide(CeO2)was modified by carboxylation to get carboxylated cerium oxide(CeO2-COOH),and a graft polymerization took place between CeO2 and aniline(An)to get core-shell structured polyaniline composites(PANI/CeO2-COOH).The structure and properties of the materials were analyzed by FT-IR,XPS,XRD,TGA,SEM and rotating disk electrochemical testing.The results reveal that the Ce III/Ce IV ratio of CeO2-COOH is approximately 1 with high surface oxygen vacancies.Meanwhile,the core-shell structured PANI/CeO2-COOH composite has the best grafting morphology,and the structure of PANI on the surface of CeO2-COOH is the same with pure PANI.PANI/CeO2-COOH is grafted via the valence bond between CeO2-COOH and PANI and shows the best thermal stability,where PANI/CeO2-COOH has the initial decomposition temperature at about 228℃and the lowest decomposition rate in the range of 200~600℃.Cyclic voltammetry and galvanostatic charge-discharge tests were performed on composite electrodes in 1 mol/L H 2SO 4.The PANI/CeO2-COOH electrode not only has excellent peak symmetry and the highest anodic peak current,but also has higher capacitance performance,where the specific capacitance reaches 149.5 F/g with the current density of 0.5 A/g.