Carbon dioxide conversion into boron/nitrogen dual-doped carbon as an electrode material for oxygen reduction reaction

Abstract

This study investigates the effect of boron/nitrogen (B/N) dual doping on the electrocatalytic activity for oxygen reduction reaction (ORR) of carbon materials that are derived from gaseous carbon dioxide (CO2) at 1atm. In the presence of NaBH4, CO2 was converted to a B-doped carbon material which was further treated with urea at 850°C for N-doping. Through RDE and RRDE measurements, the enhanced ORR activity of the B/N dual-doped carbon was confirmed in terms of both early onset potentials and large current densities. This arose from the existence of B-N related bond and pyridinic N in the carbon network. As the amount of N content increased, the carbon material became more crystalline and the B/N dual doping led to an increase in the electron transfer number of the carbon materials, implying that the ORR occurred through a dominant four-electron transfer pathway. By utilizing the abundant greenhouse gas as a carbon source, this study provides a facile means by which to synthesize B/N dual-doped carbon for enhanced electrocatalysis.