Preparation of Ti/SnO2–Sb–Ir–Mn Electrodes with Low Iridium Content for a Highly Efficient and Stable Oxygen Evolution Reaction

Electrocatalytic electrodes with low cost, excellent oxygen evolution reaction (OER) activity, and stability are urgently needed in industrial electrolysis fields. In this work, Ti/SnO2–Sb–Ir–Mn electrodes with different contents of manganese oxide are prepared by the thermal decomposition method. The results show that adding the Mn element into the Ti/SnO2–Sb–Ir electrode can induce the formation of more oxygen vacancies, thus enhancing the electrocatalytic activity. Besides, with the increase of manganese content, the accelerated life increases first and then decreases, and Ti/SnO2–Sb–Ir–Mn with a moderate Mn content (5 mol %) exhibits the best stability (243 h, 1 A/cm2). For this electrode, the preferential dissolution of the Mn ingredients in the coating at the initial stage of electrolysis results in the enrichment of the actual iridium ingredients on the coating surface, which contributes to the enhanced stability of the coating to some extent. This work provides a Ti/SnO2–Sb–Ir–Mn electrode with relatively optimal properties and offers a facile Mn doping strategy to boost the OER activity and stability of the Ti/SnO2–Sb–Ir electrode with low iridium content.