Enhanced degradation of Cephalexin via peracetic acid activation using NiCo2O4 in different dimensional morphologies: Mechanistic insights and environmental implications

This study investigates the synthesis and application of NiCo2O4 with distinct morphologies-nanorods (1D), nanosheets (2D), and flower-like structures (3D)-to enhance peracetic acid (PAA) activation for the degradation of the antibiotic cephalexin (CPX). The 3D NiCo2O4 morphology demonstrated superior properties, including enhanced crystallinity, electron transfer capabilities, and oxygen vacancies, which collectively improved the generation of reactive oxygen species. This led to a significant increase in CPX degradation efficiency within the PAA system. The 3D NiCo2O4/PAA system achieved an impressive 97.5 % degradation of CPX and notable mineralization within 30 min. The kinetic rate constant (kobs) for CPX degradation in the 3D system was 2.8 times higher than the 2D system and 8.5 times higher than the 1D system. Both radical (O2 center dot- , center dot OH, and R-O center dot) and non-radical (1O2) contributed to the degradation process, with 1O2 being the primary contributor. Additionally, this study explored parameters such as mineralization, catalyst reusability, intermediate toxicity, and degradation pathways, highlighting the potential of NiCo2O4 morphologies in environmental pollutant removal.