A comparison of the electrocatalytic activities of ordered mesoporous carbons treated with either HNO3 or NaOH

Ordered mesoporous carbon (OMC) was treated with HNO₃ or NaOH. The two treated OMCs have many oxygen-containing functional groups. Those treated with HNO₃ have more acidic surface groups than those treated with NaOH. Nicotinamide adenine dinucleotide (NADH) and H₂O₂ were selected as marker molecules for the comparison of the electrocatalytic property of the OMCs. A comparison between the cyclic voltammograms shows that the oxidation peak potential of NADH is 0.614 V at a bare glassy carbon electrode (GCE), 0.205 V at OMC/GCE, 0.223 V at NaOH-treated OMC/GCE, and 0.0 V at HNO₃-treated OMC/GCE (vs. Ag/AgCl). The results indicate that the HNO₃-treated OMC/GCE exhibits the highest electrocatalytic activity for NADH oxidation. Thus, acidic groups rather than other oxygen-containing functional groups, play a very important role in the catalytic activity of OMC.