Tao Wenyan, Li Zhenfeng, Pan Dawei, Nie Lihua, Yao Shouzhuo
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, People's Republic of China.
J Phys Chem B. 2005 Feb 24;109(7):2666-72. doi: 10.1021/jp0458607.
The fabrication, structure, electrochemical properties, and electrocatalytic properties of a manganese(III)-substituted Dawson-type phosphopolyoxotungstate, alpha 2-K7P2W17O61(Mn3+.OH2).12H2O (P2W17Mn), entrapped in polypyrrole (PPy) film have been studied. The hybrid film was prepared by potentiostatic polymerization from aqueous solution containing 20 mM pyrrole (Py) and 2 mM P2W17Mn on a pyrolytic graphite (PG) surface. Chronoamperometry, Raman spectroscopy, UV-visible absorption spectroscopy, and cyclic voltammetry were used to monitor and characterize the growth, structure, and properties of the film. The chronoamperometric curve shows that P2W17Mn can catalyze the electrochemical polymerization of Py. The Raman spectrum suggests that the doped P2W17Mn has little effect on the structure of PPy film. The P2W17Mn/PPy film exhibits good voltammetric response in both the acidic aqueous and acetonitrile solutions. At pH 1.0, the molar ratio of pyrrole to P2W17Mn7- in the hybrid film is 21.1:1, quite close to the expected ratio of 21.2:1 for a PPy film with a +0.33 oxidation level per pyrrole moiety and doped with an anion with a charge of 7. The influence of solution pH on P2W17Mn7- in the film is much smaller than that in the aqueous solution. During the potential scanning in 0.1 M LiClO4 acetonitrile solution, P2W17Mn7- was slowly released from the hybrid film and electrolyte ions (Li+ and ClO4-) were inserted into the film. This was identified by cyclic voltammetry and UV-visible spectroscopy. Additionally, the hybrid film can effectively catalyze the reduction of hydrogen peroxide and nitrite.
对包裹于聚吡咯（PPy）膜中的锰（III）取代道森型磷钨多金属氧酸盐α2-K7P2W17O61（Mn3+·OH2）·12H2O（P2W17Mn）的制备、结构、电化学性质及电催化性质进行了研究。通过恒电位聚合，在热解石墨（PG）表面由含20 mM吡咯（Py）和2 mM P2W17Mn的水溶液制备了该复合膜。采用计时电流法、拉曼光谱、紫外可见吸收光谱和循环伏安法对膜的生长、结构和性质进行监测与表征。计时电流曲线表明P2W17Mn可催化Py的电化学聚合。拉曼光谱表明掺杂的P2W17Mn对PPy膜的结构影响较小。P2W17Mn/PPy膜在酸性水溶液和乙腈溶液中均表现出良好的伏安响应。在pH 1.0时，复合膜中吡咯与P2W17Mn7-的摩尔比为21.1:1，与每个吡咯部分氧化水平为+0.33且掺杂电荷为7的阴离子的PPy膜的预期比例21.2:1相当接近。溶液pH对膜中P2W17Mn7-的影响远小于其在水溶液中的影响。在0.1 M LiClO4乙腈溶液中进行电位扫描时，P2W17Mn7-从复合膜中缓慢释放，电解质离子（Li+和ClO4-）插入膜中。这通过循环伏安法和紫外可见光谱得以确认。此外，该复合膜可有效催化过氧化氢和亚硝酸盐的还原。
