Characteristic and electrocatalytic behavior of ruthenium Prussian blue analogue film in strongly acidic media

Abstract

The remarkable stability of ruthenium Prussian blue analogue (designated as RuOx–PB) in strongly acidic media and for the enzymeless electrocatalytic oxidation of glucose was demonstrated in this study. The RuOx–PB combinative film neither dissolves nor denatures in concentrated acids, such as HClO4, HCl, H2SO4, and HNO3, investigated in this study. The catalytic response was found to directly proportional to [H+]. Such features are unique since neither RuOx- nor PB-based compounds are effective for direct carbohydrate oxidation in acidic media. The RuOx–PB film showed a highly reversible redox peak at ∼1.2V in 5M HClO4 as a result of the fast proton-coupled electron transfer behavior of high valent ruthenium intermediate, RuVII/VI. The formation of internal multiple-hydrogen bond as well as the generation of the 〉RuVIIO species in strongly acidic media were proposed to play a key role in this feature. The RuOx–PB holds high potential for use in catalytic oxidation, corrosion protection, biofuel cell, etc.