Flower cluster trees like Ti/Co₃O₄@NiZnNC composite electrodes derived from MOF for dyeing wastewater (reactive Brilliant Blue KN-R) degradation

In this paper, Ti/Co₃O₄@NiZnNC composite photoelectrodes in the shape of flower clusters were prepared by combining a p-type semiconductor with a bimetallic organic skeleton by a two-step hydrothermal method and roasting method. The morphology of the electrodes was controlled by adjusting the amount ratio of Ni²⁺ and Zn²⁺, and the photocatalytic performance of different ratios of electrodes was compared. The results show that when the quantity ratio of metal ions is 1:1, the Ti/Co₃O₄@NiZnNC-1:1 electrode has the smallest Tafel slope, the largest electrochemical active surface area, the smallest transfer resistance, and the highest photocurrent response, and the photoelectrocatalytic degradation activity of 60 mg/L of active Brilliant Blue KN-R solution can reach 96.38%. This can be attributed to the multilevel heterostructure formed by the coupling of Co₃O₄ nanowires with NiZnNC nanosheets, which in turn improves the electrochemically active surface area of the electrode, increases the catalytic reaction active sites, and enhances the separation efficiency for carriers. For the degradation mechanism of Ti/Co₃O₄@NiZnNC, we propose a reasonable type II heterostructure. This study provides an effective method for preparing more photoanodes with efficient photoelectrocatalytic properties. At the same time, it also provides new materials and ideas for the research field of wastewater treatment.