Efficient degradation of tetracycline by a novel nanoconfinement structure Cu₂O/Cu@MXene composite

In order to solve the problem of easy aggregation of copper oxides in environmental remediation, it is an effective method to confine copper oxides to suitable substrates. Herein, we design a novel Cu₂O/Cu@MXene composite with a nanoconfinement structure, and it can effectively activate peroxymonosulfate (PMS) to produce ^.OH for degradation tetracycline (TC). Results indicated that the MXene with extraordinary multilayer structure and surface negativity could fix the Cu₂O/Cu nanoparticles in the layer spaces and suppress the agglomeration of nanoparticles. The removal efficiency of TC reached 99.14 % within 30 min, and the pseudo-first-order reaction kinetic constant was 0.1505 min^-1, which was 3.2 times that of Cu₂O/Cu alone. The outstanding catalytic performance attributed that the MXene based on Cu₂O/Cu@MXene could promote the adsorption of TC and electron transmittal between Cu₂O/Cu nanoparticles. Furthermore, the degradation efficiency of TC was still over 82 % after five cycles. In addition, based on the degradation intermediates provided by LC-MS, two specific degradation pathways were proposed. This study provides a new reference for suppressing the agglomeration of nanoparticles, and broadens the application of MXene materials in the field of environmental remediation.