Improving the Electrochemical Stability of TiMn2 Middle‐Layer for Oxygen Evolution Anode in Sulfuric Acid Solution by High‐Temperature Nitriding

Abstract

AbstractDimensional Stable Anode (DSA) is a promising candidate for the electrodeposition of nonferrous metals. However, the industrial applications of DSA are limited due to the propensity of Ti substrate to easily undergo passivation. Theoretically analyses shows that TiMn2 has better corrosion resistance in highly acidic and strongly polarized environments, making it an ideal middle‐layer for DSA anodes. To investigate the corrosion resistance of TiMn2, N‐doped TiMn2 (N‐TiMn2) is prepared by the high‐temperature nitriding method. The high charge transfer resistance (Rpo) of N‐TiMn2 reduces the electron transfer ability of its surface and improves the chemical stability. Scanning electron microscopy, X‐ray diffraction, and Raman spectroscopy show that Ti/N‐TiMn2 can better inhibit the oxidation of Ti during electrochemical corrosion while forming a more stable α‐MnO2 film. The Ti/N‐TiMn2/MnO2 anode is prepared, and the theoretical lifetime reaches 541.5 days in zinc electrodeposition simulation experiments. This middle layer provides a new idea for developing the oxygen evolution anode in the electrowinning of nonferrous metals.