Copper single atoms/atomic clusters modified electrocatalytic membrane for antibiotic removal and membrane fouling control via electro-Fenton reactions

Low-pressure membrane filtration is an important technology for water treatment but suffers from the inefficient removal of low-molecular-weight pollutants (such as antibiotics) and severe membrane fouling. Herein, an electrocatalytic membrane (CuSAs/ACs-NC/CMM) modified with the catalyst containing Cu single atoms (SAs) and atomic clusters (ACs) composite active sites was prepared for the removal of tetracycline (TC) and the control of membrane fouling. Cu ACs synergistically interacted with Cu SAs, enabling a high-efficiency electro-Fenton process. In addition to serving as the main active site for the in-situ generation of H2O2, Cu ACs could also induce the charge rearrangement of Cu SAs, thus reducing the energy barrier of H2O2 activation into ·OH at the Cu SAs site. CuSAs/ACs-NC/CMM produced ·OH through a sequential reaction of H2O2 generation and activation to oxidize pollutants. At a low voltage of −2.5 V, CuSAs/ACs-NC/CMM delivered excellent TC removal kinetics (0.0181 min−1) and removal ratio (90.0 %), and effectively reduced the membrane fouling caused by the mixture of humic acid (HA), bovine serum albumin (BSA), and sodium alginate (SA). CuSAs/ACs-NC/CMM also performed well under actual water conditions. This work proposes a strategy for developing electrocatalytic membranes using catalysts with multiple atomic-level active sites, promoting the development and application of advanced membranes in water treatment.