Individual High-Quality N-doped Carbon Nanotubes Embedded with Non-Precious Metal Nanoparticles towards Electrochemical Reaction.

Developing highly active and stable non-precious metal catalysts for electrochemical reactions is desirable but remains a great challenge. Herein, we report a novel metal ion adsorption-pyrolysis strategy for the controllable ZIF-8 derived synthesis of individual high-quality N-doped carbon nanotubes embedded with well-dispersed non-precious metal nanoparticles, which exhibit superior electrocatalytic activity and stability for electrochemical CO2 reduction reaction, oxygen reduction reaction and oxygen evolution reaction. Experimental analysis and density functional theory calculations indicate that the remarkable electrocatalytic activities are mainly attributed to the interface effects for the efficient electron transfer from metal nanoparticles to the N-doped carbon shell, as well as the large specific areas, unique tube structures, appropriate doping, high graphitization degree and robust frameworks. The high reaction stability is attributed to that the multiwalled graphitic carbon shells could efficiently prevent metal nanoparticles from aggregation, corrosion and oxidation. This novel synthetic strategy presents a facile universality for synthesizing N-doped carbon nanotubes structures and will provide a guideline for developing low-cost, highly active and stable electrocatalytic materials for sustainable energy conversion.