Electrodeposition of Keggin-type heteropolyanions on different electrode surfaces from nonaqueous media

It is demonstrated that films of heteropolyanions (HPAs) can be electrodeposited onto different metallic electrode surfaces in nonaqueous media such as N,N-dimethylformamide (DMF) or N-methyl-2-pyrrolidinone (NMP) by reduction of Keggin-type (NEt(4))(3)PMo(12)O(40). For both DMF and NMP, electrodeposition gives rise to a coating. In DMF, the electrodeposition takes place during the first and second reduction steps of HPA, while in NMP, the electrodeposition takes place only during the second reduction step, which demonstrates that electrodeposition strongly depends on the solvent nature, possibly because of a process of coadsorption of the solvent during electrodeposition. (C) 2002 The Electrochemical Society.