Design of tandem CuO/CNTs composites for enhanced tetracycline degradation and antibacterial activity

Abstract

The increasingly complex situation of the water environment has put forward higher requirements for the development of functional materials for comprehensive water environmental management. Here, a facile microwave self-assembly strategy was proposed to construct a tandem copper oxide/carbon nanotube (CuO/CNTs) composite. The characterization of the structure shows that the CNTs have been associated with porous CuO nanospheres, forming an interpenetrating architecture. We identified generated reactive oxygen species including sulfate radicals (SO4−), hydroxyl radicals (OH), singlet oxygen (1O2), and superoxide radical (O2−), which can rapidly improve the degradation of tetracycline (TC). Compared with individual CuO microspheres or CNTs, the reaction rate of TC on the CuO/CNTs is improved 1.9 and 6.5 times, respectively. In addition, we confirmed that the reactive oxygen species produced had an effectively inhibitory effect on common types of bacteria. Density functional theoretical (DFT) calculations show that the adsorption energy of PMS on the opposite side of graphene is favorable (−0.517 eV). The CuO/CNTs catalysts with excellent intrinsic properties suggest its wide potential applications in wastewater treatment.