Enhanced electrooxidative dye removal using Co₂MnO₄@ZIF-67-derived anodic catalyst

Metal-organic framework-based electrocatalysis (EC) technology has emerged as an innovative approach for completely mineralising large, non-recyclable textile colouring agents in water. This process generates intermediate reactive species, such as superoxide and hydroxyl radicals, resulting in clean and environmentally friendly products, making it an attractive, pollution-free solution. For this study, a semiconductor-based composite material with a type II heterostructure was developed to serve as a photoanode, enhancing the generation of reactive radicals for effective wastewater treatment. Different concentrations of composite materials featuring ZIF-67 nanosheets were synthesised on Co₂MnO₄ nanorods using a one-step hydrothermal process on a titanium (Ti) metal. The electrochemical cell was constructed with this Ti/Co₂MnO₄@ZIF-67 anode, employing the EC method to degrade reactive brilliant blue (KN-R). The resulting electrode exhibited a large electroactive area, low charge transfer resistance, and exceptional electrochemical (EC) performance. The optimal composite anode achieved an 85.28% removal rate of reactive brilliant blue KN-R within 2 h and showed practical sustainability over five cycle tests. The EC process also analysed and discussed the mechanism based on radical trapping experiments. This work highlights the construction of Ti/Co₂MnO₄@ZIF-67 materials with a type II heterojunction, offering valuable insights into catalytic techniques for purifying organic wastewater.