FeN4 Sites Embedded into Carbon Nanofiber Integrated with Electrochemically Exfoliated Graphene for Oxygen Evolution in Acidic Medium. Issue 26 (5th August 2018)

• Record Type: Journal Article
• Authors: Lei, Chaojun; Chen, Hengquan; Cao, Junhui; Yang, Jian; Qiu, Ming; Xia, Ying; Yuan, Chris; Yang, Bin; Li, Zhongjian; Zhang, Xingwang; Lei, Lecheng; Abbott, Janel; Zhong, Yu; Xia, Xinhui; Wu, Gang; He, Qinggang; Hou, Yang
• Is Part Of: Advanced energy materials. Volume 8:Issue 26(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-08-05
• Subjects: acidic electrolyte -- electrocatalysis -- FeN4 sites -- nanocarbon -- water oxidation; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201801912
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Development of inexpensive and efficient oxygen evolution reaction (OER) catalysts in acidic environment is very challenging, but it is important for practical proton exchange membrane water electrolyzers. A molecular iron–nitrogen coordinated carbon nanofiber is developed, which is supported on an electrochemically exfoliated graphene (FeN4 /NF/EG) electrocatalyst through carbonizing the precursor composed of iron ions absorbed on polyaniline‐electrodeposited EG. Benefitting from the unique 3D structure, the FeN4 /NF/EG hybrid exhibits a low overpotential of ≈294 mV at 10 mA cm −2 for the OER in acidic electrolyte, which is much lower than that of commercial Ir/C catalysts (320 mV) as well as all previously reported acid transitional metal‐derived OER electrocatalysts. X‐ray absorption spectroscopy coupled with a designed poisoning experiment reveals that the molecular FeN4 species are identified as active centers for the OER in acid. The first‐principles‐based calculations verify that the FeN4 –doped carbon structure is capable of reducing the potential barriers and boosting the electrocatalytic OER activity in acid. Abstract : Highly active FeN4 sites for acidic electrochemical water oxidation : A novel 3D electrocatalyst based on molecular iron–nitride coordinated carbon nanofiber supported on electrochemically exfoliated graphene is successfully synthesized for electrocatalytic oxygen evolution from water splitting in acid. Highly dispersed FeN4 sites are identified as the active centers for the acidic oxygen evolution reaction.