A Universal Strategy to Design Superior Water-splitting Electrocatalysts Based on Fast in Situ Reconstruction of Amorphous Nanofilm Precursors
G. Chen, Z. Hu, Y. Zhu, B. Gu, Y. Zhong, H.-J. Lin, C.-T. Chen, W. Zhou*, and Z. Shao*
2018/12/02
The development of efficient bifunctional electrodes with extraordinary mass activity and robust stability is an eternal yet challenging goal for the water-splitting process. Surface reconstruction during electrocatalysis can form fresh-composition electrocatalysts with unusual amorphous phases in situ, which are more active but difficult to prepare by conventional methods. Here, a facile strategy based on fast reconstruction of amorphous nanofilm precursors is proposed for exploring precious-metal-free catalysts with good electronic conductivity, ultrahigh activity, and robust stability. As a proof of concept, an amorphous SrCo0.85 Fe0.1 P0.05 O3- δ (SCFP) nanofilm precursor with weak chemical bonds deposited onto a conductive nickel foam (NF) substrate (SCFP-NF) is synthesized by utilizing a high-energy argon plasma to break the strong chemical bonds in a crystalline SCFP target. The quickly reconstructed SCFP-NF bifunctional catalysts show ultrahigh mass activity of up to 1000 mA mg-1 at an overpotential of 550 mV and extremely long operational stability of up to 650 h at 10 mA cm-2 , significantly overperforming state-of-the-art precious-metal catalysts. Such a strategy is further demonstrated to be a universal method, which can be applied to accelerate the reconstruction of other material systems to obtain various efficient electrocatalysts.
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