Ever-developing energy
device technologies require the
exploration
of advanced materials with multiple functions. Heteroatom-doped carbon
has been attracting attention as an advanced electrocatalyst for zinc–air
fuel cell applications. However, the efficient use of heteroatoms
and the identification of active sites are still worth investigating.
Herein, a tridoped carbon is designed in this work with multiple porosities
and high specific surface area (980 m–2g–1). The synergistic effects of nitrogen (N), phosphorus (P), and oxygen
(O) in micromesoporous carbon on oxygen reduction reaction (ORR)/oxygen
evolution reaction (OER) catalysis are first investigated comprehensively.
Metal-free N-, P-, and O-codoped micromesoporous carbon (NPO-MC) exhibits
attractive catalytic activity in zinc–air batteries and outperforms
a number of other catalysts. Combined with a detailed study of N,
P, and O dopants, four optimized doped carbon structures are employed.
Meanwhile, density functional theory (DFT) calculations are made for
the codoped species. The lowest free energy barrier for the ORR can
be attributed to the pyridine nitrogen and N–P doping structures,
which is an important reason for the remarkable performance of NPO-MC
catalyst in electrocatalysis.