CoP-embedded nitrogen and phosphorus co-doped mesoporous carbon nanotube for efficient hydrogen evolution

Hydrogen evolution reaction (HER) through the electrochemical process at low overpotentials is vital for sustainable energy production. However, the fabrication of non-precious materials with high efficiency for the HER remains a challenge. Here, a new catalyst that consists of cobalt (Co) species embedded nitrogen (N) and phosphorus (P) co-doped carbon nanotubes (CNT) is fabricated by the polymerization of dopamine on the cobalt-nitrilotriacetic coordination polymer nanowire surface, followed by the phosphidation and carbonization under high temperature. After the pretreatment by potassium hydroxide (KOH) and the removal of metallic Co nanoparticles by sulfuric acid (H2SO4), the activated catalyst (A-Co/N,P-CNT-700) exhibits an overpotential of 44 mV to obtain 10 mA cm(-2) current density, approaching the value of commercial Pt/C catalyst (27 mV). The catalyst could easily maintain similar to 95% of its original HER activity after 15-hour stability test. The superior performance arises from the unique N-Co-P surface bonding states at the interface between CoP nanoparticles (1-4 nm) and N,P co-doped CNT. To the best of our knowledge, such HER performance is the best among noble metal free electrocatalysts in acidic electrolytes.

Automated summary

A highly efficient non-precious catalyst consisting of cobalt (Co) species embedded nitrogen (N) and phosphorus (P) co-doped carbon nanotubes (CNT) was successfully fabricated for hydrogen evolution reaction (HER) at low overpotentials. The catalyst exhibited excellent activity and stability, making it one of the best electrocatalysts in acidic electrolytes.