Heterogeneous Co@CoO composited P, N co-doped carbon nanofibers on carbon cloth as pH-tolerant electrocatalyst for efficient oxygen evolution.

• Heterogeneous Co@CoO encapsulated in P, N co-doped carbon fibers is prepared. • Synergism between Co and CoO is beneficial to improve OER. • PNC fiber benefits charge transfer and catalysis stability. • Low overpotentials of 289 (KOH) and 371 (PBS) mV at 10 mA cm−2 for OER. Heterostructured materials favoring synergism, efficient charge transfer, and abundant active sites have aroused enormous interests for water electrolysis. Here heterogeneous Co@CoO encapsulated in P, N co-doped carbon nanofibers supported on carbon cloth (Co@CoO-PNC/CC) has been prepared to pursue attractive synergism for the application of pH-tolerant catalyst for oxygen evolution reaction (OER) in both alkaline and neutral solutions. The prepared Co@CoO-PNC/CC exhibits advanced OER performances, generating a current density of 10 mA cm−2 at overpotential of 289 mV in alkaline media and 371 mV in neutral media. The high OER activity can be assigned to the synergistic effect of abundant active sites and enhanced charge transfer between Co and CoO, as well as the specific P, N co-doped carbon nanofiber architecture. [ABSTRACT FROM AUTHOR]