Postsynthetic treatment of nickel–iron layered double hydroxides for the optimum catalysis of the oxygen evolution reaction

Abstract

D.T., S.J., J.C., and V.N. wish to thank the support of the ERC CoG, 3D2DPring (GA 681544) and PoC Powering_eTextiles (GA 861673) and SFI AMBER (12/RC/2278_P2). The authors would like to thank the Advanced Microscopy Lab and CRANN Trinity College Dublin for providing STEM-EDX measurements. This publication has emanated from research supported in part by a grant from Science Foundation Ireland under Grant number 12/RC/2278_P2. For the purpose of Open Access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. Publisher Copyright: © 2021, The Author(s).Nickel–iron-layered double hydroxide (NiFe LDH) platelets with high morphological regularity and submicrometre lateral dimensions were synthesized using a homogeneous precipitation technique for highly efficient catalysis of the oxygen evolution reaction (OER). Considering edge sites are the point of activity, efforts were made to control platelet size within the synthesized dispersions. The goal is to controllably isolate and characterize size-reduced NiFe LDH particles. Synthetic approaches for size control of NiFe LDH platelets have not been transferable based on published work with other LDH materials and for that reason, we instead use postsynthetic treatment techniques to improve edge-site density. In the end, size-reduced NiFe LDH/single-wall carbon nanotube (SWCNT) composites allowed to further reduce the OER overpotential to 237 ± 7 mV ( = 0.16 ± 0.01 μm, 20 wt% SWCNT), which is one of the best values reported to date. This approach as well improved the long-term activity of the catalyst in operating conditions.publishersversionpublishe