Synergistic co-doping induced high catalytic activities of La/Fe doped Co3O4 towards oxygen reduction/evolution reactions for Zn–air batteries. Issue 44 (4th October 2022)

• Record Type: Journal Article
• Authors: Xia, Zhongyuan; Deng, Binglu; Wang, Yongjie; Jiang, Zhongqing; Jiang, Zhong-Jie
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 44(2022)
• Page Start: 23483
• Page End: 23493
• Publication Date: 2022-10-04
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2ta06726a
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : La/Fe co-doped Co3 O4 nanoparticles supported on aminated CNTs have shown high catalytic activities for the ORR and OER. The specific La/Fe co-doped structure of Co3 O4 is shown to be the main origin of their high catalytic activities. Abstract : La/Fe co-doped Co3 O4 nanoparticles supported on aminated carbon nanotubes (LaFe–Co3 O4 /NCNTs) have been demonstrated to be active bifunctional catalysts for oxygen reduction/revolution reactions (ORR/OER). With optimal La/Fe doping levels, LaFe–Co3 O4 /NCNTs exhibits an overall ORR/OER bifunctional catalytic activity higher than most catalysts reported recently. The high performance of LaFe–Co3 O4 /NCNTs mainly originates from the specific La/Fe co-doped structure of the LaFe–Co3 O4 NPs, which increases both the ORR and OER catalytic activities of the LaFe–Co3 O4 NPs to higher degrees. DFT calculations have shown that the La/Fe co-doping can decrease the overpotentials of both the ORR and the OER and increase the stability of the LaFe–Co3 O4 NPs. Additionally, carbon coating can further increase the catalytic activities of LaFe–Co3 O4 /NCNTs by the decrease of the polarization losses caused by the electrical resistance. When used in zinc–air batteries (ZABs), the carbon coated LaFe–Co3 O4 /NCNTs (C@LaFe–Co3 O4 /NCNTs) can exhibit a maximum power density of 122.2 mW cm −2, which is >20% higher than that of mixed catalysts of Pt/C + RuO2 . This, along with the much higher cycling stability of C@LaFe–Co3 O4 /NCNTs, suggests great potential for its use as a bifunctional catalyst for practical applications.