Facile Preparation of Cobalt Nanoparticles Encapsulated Nitrogen-Doped Carbon Sponge for Efficient Oxygen Reduction Reaction

Abstract

The facile preparation of non-noble metal nanoparticle loaded carbon nanomaterials is promising for efficient oxygen reduction reaction (ORR) electrocatalysis. Herein, a facile preparation strategy is proposed to prepare nitrogen-doped carbon sponge loaded with fine cobalt nanoparticles by the direct pyrolysis of the cobalt ions adsorbed polymeric precursor. The polymeric sponge precursor with continuous framework and high porosity is formed by the self-assembly of a poly(amic acid). Taking advantage of the negatively charged surface and porous structure, cobalt ions can be efficiently adsorbed into the polymeric sponge. After pyrolysis, fine cobalt nanoparticles covered by carbon layers are formed, while the sponge-like structure of the precursor is also well-preserved in order to give cobalt nanoparticles loaded nitrogen-doped carbon sponges (Co/CoO@NCS) with a high loading content of 44%. The Co/CoO@NCS exhibits promising catalytic activity toward ORR with a half-wave potential of 0.830 V and a limiting current density of 4.71 mA cm−2. Overall, we propose a facile polymer self-assembly strategy to encapsulate transition metal nanoparticles with high loading content on a nitrogen-doped carbon sponge for efficient ORR catalysis.

Efficient Removal of Pb(Ⅱ) by Highly Porous Polymeric Sponges Self-Assembled from a Poly(Amic Acid)

“…The synthesis of PAA was carried out according to our previous publication, as shown in Scheme S1 [ 34 , 35 ]. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H NMR) were conducted to confirm the structure of PAA ( Figures S1 and S2 ) [ 34 , 35 ].…”

“…The synthesis of PAA was carried out according to our previous publication, as shown in Scheme S1 [ 34 , 35 ]. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H NMR) were conducted to confirm the structure of PAA ( Figures S1 and S2 ) [ 34 , 35 ]. The PAA sponge was prepared by directly adding deionized water to the PAA solution (30 mg mL −1 ), diluted by the stock solution with N , N -dimethylformamide (DMF).…”

Homopolymer Self-Assembly: Principles, Driving Forces, and Applications

“…With 55.0% active nitrogen species (pyridinic and graphitic nitrogen) and 8.4% substantial nitrogen content, which was regarded as the origin of the oxygen reduction reaction (ORR) catalytic activity, the NCS showed remarkable catalytic efficiency and durability for the ORR catalysis. The relative current density was as high as 92.4% after 30 h. Furthermore, this carbon sponge with abundant micropores and mesopores could support ultrafine Co/CoO nanoparticles for ORR catalysis . Due to the interconnected pores, efficient nitrogen doping, and small size of Co/CoO nanoparticles, this new catalyst exhibited similar catalytic activity to ORR as Pt/C.…”

“…The relative current density was as high as 92.4% after 30 h. Furthermore, this carbon sponge with abundant micropores and mesopores could support ultrafine Co/CoO nanoparticles for ORR catalysis. 123 Due to the interconnected pores, efficient nitrogen doping, and small size of Co/CoO nanoparticles, this new catalyst exhibited similar catalytic activity to ORR as Pt/C.…”

“…Homopolymer self-assembly also shows potentials in water treatment, catalysis and energy storage. ,,, In this section the applications in catalysis, , energy storage, , and water treatment will be summarized.…”