Low-Cost Chitosan-Derived N-Doped Carbons Boost Electrocatalytic Activity of Multiwall Carbon Nanotubes

An effective strategy is proposed to enhance the oxygen reduction reaction (ORR) performance of multiwall carbon nanotubes (MWCNTs) in both acid and alkaline electrolytes by coating them with a layer of biomass derivative N-doped hydrothermal carbons. The N-doped amorphous carbon coating plays triple roles: it (i) promotes the assembly of MWCNTs into a 3D network therefore improving the mass transfer and thus increasing the catalytic activity; (ii) protects the Fe-containing active sites, present on the surface of the MWCNTs, from H2O2 poisoning; (iii) creates nitrogenated active sites and hence further enhances ORR activity and robustness.