Abstract:

Oxygen reduction reaction is a crucial process for fuel cells. Conventional oxygen reduction catalysts are the precious metal platinum， but given the high cost of platinum， researchers want to find a low-cost alternative catalyst that is cheaper and has the equivalent catalytic activity to platinum. In previous studies， iron-nitrogen-doped graphdiyne and cobalt-nitrogen-doped graphdiyne have been studied， and they all show efficient oxygen reduction reaction activity， while nickel， with similar electronic structure with iron and cobalt， has not been studied. Therefore， in this work we design and synthesize various nickel-nitrogen-doped graphdiyne electrocatalysts using hydrogen as a substitute for graphiyne， and conduct redox electrochemical tests. The nickel-nitrogen-doped graphdiyne catalyst containing 2% nickel and melamine shows the best electrocatalytic performance for oxygen reduction. We conduct a series of physical characterizations for the catalysts： X-ray diffraction （XRD）， X-ray photoelectron spectroscopy （XPS）， transmission electron microscope （TEM）， scanning electron microscope （SEM） to further analyze their structure and morphology. It can be seen from the physical characterization and electrochemical tests that nitrogen atoms are the key to construct the catalytic active site， and nickel atoms play a vital role in improving the performance of the catalysts. With the synergistic effect of nitrogen and nickel， the nickel nitrogen-doped graphdiyne catalyst shows excellent catalytic performance， which makes it have a good application prospect.

Key words: Nickel-nitrogen-doped graphdiyne, Oxygen reduction reaction, Electrocatalysis, synergistic effect