Alginate derived Co3O4/Co nanoparticles decorated in N-doped porous carbon as an efficient bifunctional catalyst for oxygen evolution and reduction reactions. (1st March 2018)

• Record Type: Journal Article
• Authors: Zhan, Tianrong; Lu, Sisi; Liu, Xiaolin; Teng, Hongni; Hou, Wanguo
• Is Part Of: Electrochimica acta. Volume 265(2018)
• Page Start: 681
• Page End: 689
• Publication Date: 2018-03-01
• Subjects: Sodium alginate -- Co, N-doped carbon material -- Oxygen evolution reaction -- Oxygen reduction reaction -- Bifunctional catalyst; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.02.006
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Fabricating high-performance and low-cost bifunctional electrocatalysts for both oxygen evolution and reduction reactions is vital for the practical application of renewable energy conversion. Herein, a hybrid of Co3 O4 /Co active species incorporated in N-doped porous carbon matrix, denoted as Co3 O4 /Co-NPC, has been prepared using a scalable and facile method involving the carbonization of alginate composite after a Co ion exchange with sustainable seaweed biomass. The 3D Co3 O4 /Co-NPC exhibits good bifunctional oxygen electrocatalytic performance in alkaline medium. The proposed catalyst gives the smaller onset potential (1.450 V vs. RHE) and overpotential (277 mV) at 10 mA cm −2 current density, indicating a superior oxygen evolution reaction activity to commercial IrO2 catalyst. It also performs the excellent oxygen reduction catalytic activity with larger onset potential (0.91 V vs. RHE), more positive half wave potential (0.806 V vs. RHE) and bigger diffusion-limiting current density (−5.86 mA cm −2 at 0.4 V). The Co3 O4 /Co-NPC hybrid experiences an almost ideal 4e process with better long-term stability and anti-methanol ability than commercial Pt/C catalyst in 0.1 M KOH. The prominent bifunctional activity of Co3 O4 /Co-NPC can be due to the synergistic effects of the well dispersed Co3 O4 /Co active species and N-doped porous carbon nanostructure. Highlights: The Co3 O4 /Co-NPC was prepared by direct carbonization of Co ions coupled alginate composite. Co3 O4 /Co-NPC exhibits a porous structure with a surface area of 496.4 m 2 /g and wide mesopore size distribution (2.2–32.1 nm). Co3 O4 /Co-NPC shows better OER activity with a lower onset overpotential of 220 mV. Co3 O4 /Co-NPC gives a 0.91 V ORR onset potential almost involving a 4e pathway.