Dimethylimidazole and dicyandiamide assisted synthesized rich-defect and highly dispersed CuCo-Nx anchored hollow graphite carbon nanocages as efficient trifunctional electrocatalyst in the same electrolyte

Abstract

This paper introduces a facile method to disperse rich-defect CuCo-N x active sites onto hollow graphite carbon nanocages, through one-pool dicyandiamide-assisted pyrolysis of porous CuCo-PBA-2MI precursor. The as-prepared CuCo-N x @N-CCs composites exhibit favorable electrocatalytic activity and robust durability for oxygen reversible catalysis (ORR/OER) and hydrogen evolution reaction (HER) in the same low concentration alkaline electrolyte (0.1 M KOH), including E ORR, 1/2 = 0.80 V, E OER, 10 = 1.58 V and E HER, 10 = −0.319 V. The nanocomposites show the superior electrocatalytic practical application in Zn-air batteries self-driven overall water splitting. Insights into the experimental analyses reveal that during the pyrolysis process, CuCo-PBA-2MI precursor captures volatile CN x active species from dicyandiamide, eventually forming high dispersed CuCo-N x active sites with unique N-doped porous hollow carbon scaffolds structure. Such hollow nanocage structures can effectively protect the active site from agglomeration and uneven distribution. It also prevents nanomaterials corrosion from alkaline electrolyte in the electrocatalytic reaction process. We believe that this strategy will offer useful guidelines to researchers who are interested in developing advanced and performance-oriented multifunctional electrocatalysts for clean energy devices. • Dimethylimidazole promoted the generation of hollow nanocage. • Dimethylimidazole acts as both a competitive ligand and a carbon/nitrogen source. • The dimethylimidazole and dicyandiamide make CuCo-N x active sites uniformly dispersed. • Unique hollow nanocage structure can prevent agglomerate and shedding of active sites. • CuCo-N x @N-CCs has excellent trifunctional electrocatalytic properties in same electrolyte.