Preparation And Electrochemical Properties Of Cobalt-based Prussian Blue Compounds/Hollow Carbon Microsphere Composites

Electrolysis of water to produce hydrogen is a way to provide clean and sustainable energy,and it is an efficient electrochemical conversion technique.Among them,anode oxygen evolution reaction(OER)has a relatively slow kinetics,which limits the whole process of electrolysis of water.Prussian blue analogues with transition metal-organic frameworks(MOFs)are viewed as the high performance electrocatalysts,while how to achieve the decoration of metal sites without damage for improving reactivity is still challengable.In this study,with nitrogen-doped hollow carbon microspheres and Co(NO3)2 as precursors,a nanocomposite catalyst(PB-Co/Co-N-PHCS)of(Co3[Co(CN)6]2 PB-Co)and hollow carbon microsphere was prepared by using low-cost hydrothermal.SEM,TEM,Raman,XRD,XPS,BET and other methods were used to characterize the structure and specific surface of the prepared samples.PB-Co/Co-N-PHCS showed high graphitization degree(IG/ID=1.22)and large surface area(1545.8 m2/g).Benefiting from multiple active sites(Co nanoparticles coated with PB-Co nanolayers,Co nanoparticles coated in graphite carbon shells,Co-Nx centers and doped nitrogen atoms),hierarchical porous structure,and high conductivity hollow carbon shell,the as-prepared nanocomposite catalyst showed remarkable electrocatalytic activity and durability for OER in 0.1 M KOH.PB-Co/Co-N-PHCS was used a bifunctional electrocatalyst for overall water splitting,it delivered a current density of 10 mA/cm2 at the voltage of 1.6 V.This work provides a new possibility for the development of electrocatalysts for overall water splitting.Due to the high specific surface area(SSA)and appropriate pore structure of N-doped porous hollow carbon microspheres(N-PHCS),this paper further studied the energy storage performance of N-PHCS.In the 1 M H2SO4 electrolyte,N-PHCS presented a higher specific capacitance(Csp).At the current density of 1A/g,the Csp value was 340 F/g,and at the high current density of 10A/g and 15 A/g,the Csp value could still reach 212 F/g and 194 F/g.