Pyridinic-N-enriched mesoporous carbon coated carbon cloth for efficient oxygen evolution reactions

Abstract

Electrochemical oxygen evolution reaction (OER) plays an important role in the field of energy conversion/storage, but highly efficient electrocatalysts are required to overcome the barrier out of slow four-electron transfer oxygen kinetics. Herein, pyridinic-N doped activated carbon cloth (NACC) is prepared by successive KOH activation and urea pyrolysis and applied as an efficient OER electrocatalyst. Experimental results reveal that NACC shows a lower overpotential of 239 mV at the current density of 10 mA cm⁻², a small Tafel slope of 58 mV dec^-1 and excellent durability, which are significantly prior to those of pristine CC. The improved electrochemical behaviors of NACC could be ascribed to the pyridinic-N doping leaded large increase in active sites, efficient charge/mass transfer and easy adsorption of hydroxide anions as well as intermediate products on active sites. Moreover, the density functional theoretical (DFT) calculations conclude that pyridinic-N-doping occurs at the zigzag edges of structural defects in carbon sheets, and the meta- or ortho-carbon atoms of pyridinic-N atoms are the main active sites, which are responsible for the outstanding OER performance of NACC.