Preparation of a Composite Film Electrode Containing 12‐Tungstosilicic Acid and Its Electrocatalytic Reduction for Nitrite

A novel organic‐inorganic composite film was formed by attaching Keggin‐type heteropolyanion, SiW12O404−(devoted briefly as SiW12), on a glassy carbon electrode derivatized by 4‐aminophenyl group. The composite film has an ionic bonding character between SiW12and the surface amino group, which greatly improves the film stability and exhibits a more reversible electrochemical behavior. The modified electrode offers an excellent and stable electrocatalytic response for the reduction of nitrite. Possible mechanism was provided for the reaction of nitrite with SiW12O404−/aminophenyl composite film.