Surface functionalization of polyaniline and excellent electrocatalytic performance for oxygen reduction to produce hydrogen peroxide

Electrochemical two-electron oxygen reduction is an environmental-friendly and promising method to generate H2O2. However, a great challenge remains to develop more economic and effective electrocatalysts for practical application. Here, we have developed a [email protected] electrocatalyst that is significantly different from the conventional electrocatalyst previously reported (such as metal, alloy, carbon materials doped with heteroatoms, metal single-atom catalysts). We firstly find that the polyaniline (PANI) treated by dilute nitric acid can be changed into the PANI-NO product with the functional group of –NO. Then we introduce the PANI-NO on the surface of carboxylated carbon nanotubes to obtain the [email protected] nanocomposites, which exhibit excellent electrochemical performance to H2O2 production. The H2O2 selectivity of the typical [email protected] is between 87% and 94% at the potential of 0.2–0.68 V (vs. RHE), the faradaic efficiency is close to 95% and the current density is up to 2.9 mA/cm2 (at 0.3 V) in alkaline condition. The DFT results give the origin of the catalytic activity. This study provides a new idea for the application of polymer in electrocatalysis and a new way to develop the high-performance 2e-ORR electrocatalyst.