Synergistic electrocatalytic reduction-oxidation cascade for efficient degradation of triclosan over an optimal...

To enhance the catalytic activity of the electrochemical electrode, this study utilizes amino-ionic liquid functionalized graphene to support a cobalt-nickel composite material (NH₂-IL/RGO/CoNi), which is prepared as a catalytic cathode for the electrocatalytic degradation of triclosan. This study controllably adjusts the structural morphology of the catalyst by varying the amounts of amino-ionic liquid (NH₂-IL) and metal, resulting in the selection of the highly active composite material. SEM and TEM analysis revealed that the optimal catalyst (mass ratio of NH₂-IL: GO was 1:1 and 1.5% Co and 1.5% Ni theoretical loading) had uniformly dispersed CoNi NPs of 1.990 nm. The introduction of NH₂-IL significantly enhanced the performance, yielding an approximately 2.9-fold higher current intensity for NH₂-IL/RGO/CoNi versus RGO/CoNi. The results from XRD and Raman spectroscopy indicate that NH₂-IL can be functionalized via π-π stacking and cation-π interactions with the RGO surface, while its cations and anions attract metal ions through electrostatic interactions, thereby promoting the synergistic enhancement of the catalytic activities of Co and Ni particles. Compared to RGO/CoNi, the NH₂-IL/RGO/CoNi cathode achieves a 99.3% removal rate for triclosan (TCS) within 120 min, demonstrating superior degradation efficiency and high catalytic activity. Analysis of the degradation intermediates identified six products, indicating that ether bond cleavage and hydrodechlorination are the predominant pathways. Under this cathode's action, TCS undergoes hydrodechlorination followed by ·OH-mediated oxidative degradation. This finding underscores the potential of NH₂-IL/RGO/CoNi for degrading chlorinated PPCPs, presenting a promising avenue for addressing water contamination.