Cobalt-based multicomponent nanoparticles supported on N-doped graphene as advanced cathodic catalyst for zinc-air batteries

To improve the efficiency of cathodic oxygen reduction reaction(ORR)in zinc-air batteries(ZABs),an adsorption-complexation-calcination method was proposed to generate cobalt-based multicomponent nanoparticles comprising Co,Co_(3)O_(4)and CoN,as well as numerous N heteroatoms,on graphene nanosheets(Co/Co_(3)O_(4)/CoN/NG).The Co/Co_(3)O_(4)/CoN nanoparticles with the size of less than 50 nm are homogeneously dispersed on N-doped graphene(NG)substrate,which greatly improve the catalytic behaviors for ORR.The results show that the half-wave potential is as high as 0.80 V vs.RHE and the limiting current density is 4.60 mA·cm^(−2),which are close to those of commercially available platinum/carbon(Pt/C)catalysts.Applying as cathodic catalyst for ZABs,the battery shows large specific capacity and open circuit voltage of 843.0 mAh∙g^(−1) and 1.41 V,respectively.The excellent performance is attributed to the efficient two-dimensional structure with high accessible surface area and the numerous multiple active sites provided by highly scattered Co/Co_(3)O_(4)/CoN particles and doped nitrogen on the carbon matrix.