Platinum modified nickel nitride catalyst on carbon nanotubes for energy conversion in alkaline medium
Designing and exploiting low loading Platinum (Pt) based electrocatalysts are critical in the electrochemical reaction because of its high-efficiency in alkaline conditions for energy conversion. Herein, electrocatalysts of NiNx@Pt nanoparticles deposited on surface of functionalized carbon nanotubes (CNTs) have been prepared by simple sintering and reduction reaction, and then applied as electrocatalyst for methanol oxidation reaction (MOR), oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Under alkaline medium, a current density of 610.4 mA mg−1Pt for MOR is demonstrated which is 1.35 times higher than that of commercial 20 wt% Pt/C (451.2 mA mg−1Pt) catalysts. Besides, the NiNx@Pt/CNT electrocatalyst exhibits more excellent ORR electrocatalytic activity with an onset potential of 0.986 V and half-wave potential of 0.862 V, and an overpotential of 530 mV and low potential gap of 0.89 V for OER. The deposited NiNx nanoparticles not only serve as the center of catalyst with favorable electronic structure, but also effectively prompt the electron transport from Pt nanoparticles to carbon nanotubes. Overall, extraordinary electrocatalysis activity is presented for the versatile NiNx@Pt/CNT electrocatalyst for multiple electrochemical reactions.