Metal nanoparticles (NPs) are an important class of materials for electrocatalysis. Synthesis of metal NPs with uniform particle size below 10 nm without a capping agent is challenging due to the tendency of particle aggregation to minimize surface energy. Here we demonstrate that pyrolysis of a metal-TCNQ (TCNQ−=tetracyanoquinodimethane radical anion) compound can produce metal NPs with controllable particle sizes anchored on nitrogen doped carbon (denoted as MetalNC). NiNC and CoNC derived from Ni-TCNQ and Co-TCNQ with Ni and Co particle sizes below 10 nm were successfully prepared. NiNC, with a particle size of 8.8 nm, showed excellent catalytic activity for hydrogen evolution in an alkaline medium, reaching a catalytic current density of 10 mA cm−2 at an overpotential of 230 mV. CoNC, with a particle size of 1.8 nm, exhibited the capability of producing syngas by electrocatalytic CO2 reduction over a wide potential range in an acetonitrile medium containing 0.3 M H2O. An artificial photosynthesis system based on CoNC achieved faradaic efficiencies of over 70 % for production of syngas and 22 % for formate. This work demonstrates a general strategy to synthesize size controllable metal NPs supported on carbon materials for electrocatalytic energy conversion.
- metal nanoparticles
Peter Miller (Manager)Office of the Vice-Provost (Research and Research Infrastructure)
James Griffith (Manager)Office of the Vice-Provost (Research and Research Infrastructure)