Nanoarchitecture of Cobalt Phthalocyanine for Enhanced Chloramphenicol Hydrodechlorination through Direct Electron-Transfer Mechanism

Abstract Electrocatalytic hydrodechlorination (ECHD) provides a sustainable method for treating water polluted with chlorinated organic compounds under ambient conditions. Cobalt phthalocyanine (CoPc) represents a molecular catalyst with economic benefits and high selectivity, although its performance is limited by significant molecular stacking. To this end, we constructed ordered CoPc nanotubes (CoTs) for ECHD studies, alongside conventional CoPc single molecules and disordered aggregates as reference systems. All materials catalyzed ECHD via a direct electron transfer (DET) route on the CoPc active state under turnover conditions. The ordered CoT architecture accelerated interfacial and internal electron transfer, boosting the intrinsic activity. Degradation involves simultaneous reduction of terminal nitro and chloro groups, and the latter is suggested to follow an energetically favorable remote attack pathway. At full chloramphenicol (CAP) conversion, CoTs delivered an ECHD ratio of 83.9%, which is superior to recent benchmarks. For practical use, a flow-cell system achieved a treatment flux of 6.79 L h–1 g–1, which is 5 times that of a standard H-cell. This work underscores the pivotal role of molecular ordering in enhancing ECHD and offers design guidelines for non-noble metal heterogeneous electrocatalysts.