Abstract:
Efficient and sustainable water electrocatalysis requires a stable and effective OER catalyst that
is derived from low-cost and earth-abundant sources. This work involves the use of a simple
ultrasound nanopore-confinement method to grow highly dispersed Ni/Co catalysts on a porous
carbon nitride (PCN) network having a large surface area using a single source precursor for
carbon/nitrogen source. This process successfully restricts the growth of metal catalysts to sub-
1 nm. The good dispersion of the metal components on the PCN support was confirmed using
HRTEM, HAADF-STEM, and elemental mapping images. The structure of the catalyst was
characterized using XRD and XPS. Incorporating Ni or Co into PCN significantly reduces the
OER overpotential to achieve 10 mAcm-2
compared to the pristine PCN network, with the
overpotential of 245 mV (vs. RHE) for Co-f-PCN, 255 mV (vs. RHE) for Ni-f-PCN, and 310
mV (vs. RHE) for PCN. The small Tafel slope values of the three catalysts (PCN~ 67.8 mV/dec;
Co-f-PCN ~ 44.22 mV/dec and Ni-f-PCN ~ 46.8 mV/dec) indicate that incorporating Ni or Co
into PCN enhances the OER. Furthermore, the PCN, Co-f-PCN, and Ni-f-PCN catalysts
demonstrated exceptional long-term durability, with only a minimal attenuation of about 4%
after 24 hours. This method allows the integration of Ni or Co into the PCN network with a
high N content and a high surface area, significantly enhancing electrocatalytic OER activity
and conductivity.
