Directional Reconstruction of Iron Oxides to Active Sites for Superior Water Oxidation
Haijun Liu, Shuo Zhang, Wenyu Yang, Ning Yu, Chun‐Ying Liu, Yong‐Ming Chai, Bin Dong
Abstract
Abstract Rationally constructing and manipulating the in situ formed catalytically active surface of catalysts remains a tremendous challenge for a highly efficient water electrolysis. Herein, an anion and cation co‐induced strategy is presented to modulate in situ catalyst dissolution‐redeposition and to achieve the directional reconstruction of Zn and S co‐doped Fe 2 O 3 and Fe 3 O 4 on iron foams (Zn,S‐Fe 2 O 3 ‐Fe 3 O 4 /IF), for oxygen evolution reaction (OER). Benefiting from Zn, S co‐doping and the presence of Fe 3 O 4 , a directionally reconstructed surface is obtained. The Fe 2 O 3 in the Zn,S‐Fe 2 O 3 ‐Fe 3 O 4 /IF is directionally reconstructed into FeOOH (Zn,S‐Fe 3 O 4 ‐FeOOH/IF), in which the S leaching promotes the Fe dissolution and the Zn co‐deposition regulates the activity of the obtained FeOOH. Moreover, the presence of Fe 3 O 4 provides a stable site for FeOOH deposition, and thus causes more FeOOH active components to be formed. Directionally reconstructed Zn,S‐Fe 3 O 4 ‐FeOOH/IF outperformes many state‐of‐the‐art OER catalysts and demonstrates a remarkable stability. The experimental and density functional theory (DFT) calculation results show that the introduction of Zn‐doped FeOOH with abundant oxygen vacancies through directional reconstruction has activated lattice O atoms, facilitating the OER process on the heterojunction surface following the lattice oxygen mechanism (LOM) pathway. This work makes a stride in co‐induced strategy modulating directional reconstruction.