Catalytic hydrolysis of β-lactam antibiotics via MOF-derived MgO nanoparticles embedded on nanocast silica

Abstract

The antibiotics abuse and the proliferation of antibiotic-resistant bacteria in the environment have a severe impact on both human health and ecosystem. In this study, a silica-nanocasting method was applied in Mg-MOF-74 template to generate a series of MgO/SiO₂ catalysts for the hydrolysis of β-lactam antibiotics. The Mg-based subunits in MOF-74 were converted to highly dispersed MgO nanoparticles with controllable particle size. MgO/SiO₂-80 with the smallest MgO particle size exhibits the best catalytic performance in the hydrolysis of four β-lactam antibiotics. The kinetics study reveals the higher degradation rate and lower activation energy of MgO/SiO₂-80 than other benchmark solid base catalysts. The proposed mechanism suggests that small MgO particle size provides more accessible oxygen anions with high proton affinity for the cleavage of the β-lactam ring, so that all hydrolytic products lose antimicrobial activity. The MgO/SiO₂-80 serves as the potential high-performance solid base catalyst for the real-world antibiotic wastewater treatment.

Keywords: Antibiotic hydrolysis; Half-life; MOF-derived MgO nanoparticle; Mechanism; Metal-organic framework.