盘状多酸P_5W_(30)/阳离子聚电解质/氧化石墨烯杂化多层膜的电致变色性能

为了提高薄膜PEI/P_5W_(30)]_(30)的电致变色性能,将具有大的二维尺寸和良好导电性的氧化石墨烯引入该薄膜中。通过层层自组装(LBL)技术构筑了基于盘状多酸K12.5Nal.5Na P_5W_(30)O_(110)]·15H_2O(P_5W_(30))、氧化石墨烯(GO)的复合薄膜PEI/P_5W_(30)/PEI/GO]_(30)(PEI:聚乙烯亚胺),并利用UV-Vis光谱对薄膜的组成及增长进行监测;通过原子力显微镜对薄膜的表面形貌进行考察,利用循环伏安法对薄膜电化学氧化还原性质进行研究;薄膜在外加氧化还原电位下呈现出无色/蓝色的可逆变化,电致变色响应时间在10 s以内;此外,薄膜在阶跃电位0.75 V/-0.75 V下循环150次,电致变色性能没有明显减弱,体现了薄膜良好的电致变色可逆性。氧化石墨烯的引入使薄膜PEI/P_5W_(30)/PEI/GO]_(30)呈现出响应速度快、抗电疲劳强的电致变色性能,将在电致变色器件领域有广阔的应用前景。

Electrochromic Properties of Hybrid Mutilayer Film Based on Pressler Type Polyoxometalate P5W30, Positive Polyelectrolyte and Graphene Oxide

To improve the electrochromic performance of thin film PEI/P₅W₃₀]₃₀(PEI:polyethyleneimine), graphene oxide with large two-dimensional size and excellent electrical conductivity was incorporated. We have fabricated an organic/inorganic hybrid thin film PEI/P₅W₃₀/PEI/GO]₃₀ based on Preyssler-type polyoxometalate K_12.5Na_l.5NaP₅W₃₀O₁₁₀]·15H₂O(P₅W₃₀) and graphene oxide(GO) by layer-by-layer method(LBL). The composition and growth process of the film were characterized by ultraviolet-visible(UV-Vis) spectrophotometer. We investigated the morphology by atomic force microscopy(AFM) and studied the electrochemical properties by cyclic voltammetry of the multilayers. The film displays reversible electrochromic behavior from colorless to blue when applied a redox potential, and the response time of the coloring and discoloring process are all within 10 seconds. More importantly, the electrochromic property has no obvious change after 150 cycles under double potential step at 0.75 V and -0.75 V, the electrocromic film reflects a good reversibility. The film of PEI/P₅W₃₀/PEI/GO]₃₀ exhibits fast response, long durability after GO embedding, and has a potential application in electrochromic devices.