Effect of Outer Carbon Layer Thickness of Carbon-covered N-doped Hollow Carbon Nanospheres on Its Electrocatalytic Performance

Hollow nitrogen-doped porous carbon materials covered with different thicknesses of carbon layers were synthesized to assist evaluation of the influence of nitrogen atom on the surrounding carbon atoms. The designed carbon-based materials were synthesized through pyrolysis of surface-attached block copolymer layers on silica nanoparticles with different thicknesses of the second block of grafted polymer chains, followed by removal of silica templates. The experimental results reveal that coverage a carbon layer with proper thickness can improve the oxygen reaction reduction activity of nitrogen-doped carbon materials as evidenced by the positive shift of half-wave potential in linear scanning voltammetry response curves. The conclusions may provide a reference work on understanding the active sites and designing materials with superior electrochemical performance.