For a control experiment, CMK-3 (50 mg) was prepared in the presence of dissolved anthraquinone (5 mg, 10 wt. %) in ethanol (5 mL). The suspension was stirred for 2 hours then kneaded to create an electrode film. Similarly, another control experiment followed the diazonium radical reaction without the addition of the radical initiator. CMK-3 (50 mg, 1 equiv.) and 2-AAQ (0.28 g, 0.3 equiv.) were stirred in degassed acetonitrile for 16 hours under N2 and then washed following the synthetic procedure explained above.