Cytosine-Co assemblies derived CoNx rich Co-NCNT as efficient tri-functional electrocatalyst

Carbon-metal composites are promising multifunctional electrocatalysts , but it is still challenging to prepare carbon-metal composites with tunable structure and strong metal-carbon interactions. Here, we present a unique gas-foaming assembly strategy to prepare cytosine-Co chelate derived Co and N codoped carbon nanotube (Co-NCNT). The structure for Co-NCNTs could be easily controlled by regulating cytosine-Co coordination or the carbonization temperature. The optimal Co-NCNT possesses homogeneous distributed NCNTs (10 nm), CoO x (5 nm) and CoN x moieties to synergistically boost electrochemical processes, and offer mesoporous nanosheet architecture to guarantee fast mass migrate and electron transfer . As a result, Co-NCNT shows remarkable ORR performance (onset potential of 0.93 V in 0.1 M KOH electrolyte) along with significant OER and HER activity. More important, it was found that CoN x moieties are responsible for the remarkable electrocatalytic activity in Co-NCNTs, because CoN x could alter active center, enhance metal-carbon synergy, decrease interfacial resistance and reinforce the strength of composites. Therefore, this paper not just demonstrates an advanced multi-functional electrocatalyst, but could also give deep understanding on the designing of multifunctional electrocatalysts.