Efficient antibiotic degradation catalyzed by oxygen vacancy and Cu-Doped Cu-MOF under visible light

Abstract

The widespread use of antibiotics in contemporary healthcare has led to their accumulation in natural water systems, contributing to a growing resistance among bacteria and posing a significant challenge to the sustainable development of human society. Photocatalysis has emerged as an effective technique to mitigate antibiotic pollution in water. This study focuses on developing and synthesizing a visible light responsive metal–organic framework (MOF), Cu-NTC, which employs copper as the metal node instead of the usual choice of molybdenum, and the rigid 1,4,5,8-naphthalene tetracarboxylic acid (H4NTC) as the organic ligand. A pivotal step in the synthesis involved the partial reduction of Cu2+, leading to the formation of Cu0/Cu+ doping. This doping, together with oxygen vacancies (OVs), introduces a localized state that functions as a doped energy level, thus prolonging carrier lifetime and enhancing the visible light photocatalytic activity of Cu-NTC. Remarkably, Cu-NTC achieved photocatalytic degradation efficiencies of 84.5 % for tetracycline (TC) and 96.1 % for norfloxacin (NFX) after 30 min in darkness followed by 120 min under visible light exposure. Moreover, Cu-NTC exhibited effective removal capabilities for other antibiotics within the quinolone and tetracycline groups, underscoring their potential for broader applications in water purification.