Functionalized ITO electrodes are used to regenerate NADH using [Cp*Rh(bpy)(H2O)](2+) (Cp* = pentamethylcyclopentadienyl, bpy=2,2'-bipyridine) electrochemically in a buffer solution. Amino- and mercapto-functionalized electrodes featured higher activity and stability for electrocatalytic generation of NADH than a bare ITO electrode. Effect of metal nanoparticles was also studied on modified ITO electrodes and the addition of platinum nanoparticles even resulted in improved activity. The electrochemical regeneration was somewhat affected in the presence of dioxygen, but not significantly. In addition, a conversion of carbon dioxide was carried out utilizing the electrochemically generated NADH and formate dehydrogenase to produce formic acid. (C) 2013 Elsevier Ltd. All rights reserved.