Electro-oxidation of organic fuels catalyzed by ultrasmall silicon nanoparticles

Ultrasmall colloidal silicon nanoparticles behave as electrocatalysts for the oxidation of ethanol, methanol, and glucose. Electrochemical characterization of particle-immobilized electrodes shows a catalytic onset between -0.4 and 0 V versus Ag/AgCl at neutral pH. The onset potential and the catalytic strength are dependent on the particle size. A prototype hybrid biofuel cell was constructed, using the particles as the anode catalyst. The catalytic activity undergoes a 50-fold increase under alkaline condition compared to that under acidic condition. An unexpected light dependence of the catalytic current was observed. A significant increase in the catalytic current is obtained when the catalysis is performed in darkness.