Cu-based　nanocatalysts　have　received　much　attention　for　their　high　efficiency　and　environmental　friendliness　in　heterogeneous　electro-Fenton　(hetero-EF)　technology.　However,　designing　catalysts　posses　high　stability　and　efficient　pollutant　degradation　performance　remains　challenging.　In　this　work,　a　novel　binder-free　copper　foam　(CF)-supported　CuxO　nanorod　array　electrode　was　prepared　by　solvothermal　and　calcination　methods　and　used　for　the　degradation　of　sulfamethoxazole　(SMX).　The　hetero-EF　system　with　CuxO　NRs/CF-300　°C　as　cathode　achieved　100　%　SMX　degradation　in　90　min.　Experimental　and　theoretical　calculations　showed　that　the　coexistence　of　Cu0,　Cu+,　and　Cu2+　in　Cu-based　catalysts　promotes　the　generation　of　·O2–　and　facilitates　redox　cycling　of　Cu　species　(Cu+/Cu2+),　thus　enhancing　SMX　degradation　efficiency.　In　addition,　CuxO　NRs/CF-300　°C　expanded　the　pH　range　(3–11)　and　exhibited　remarkable　stability,　making　it　an　excellent　synthetic　electrode　material　with　production　potential.　This　discovery　successfully　overcame　the　low　and　unstable　Cu+　activation　capacity　and　the　short　lifetime　of　reactive　oxygen　species　in　conventional　heterogeneous　reactions.　This　work　provides　a　practical　approach　for　developing　reliable　Cu-based　nanocatalysts　and　facilitating　the　degradation　of　organic　contaminants.　©　2024　Elsevier　B.V.