Electrochemical Synthesis of Cu-MOFs for Photoelectrochemical Degradation of Hormones

Abstract

Combining adsorbents with photocatalysts is promising for treating waters containing trace pollutants, but typical adsorbents have low photoactivity and can shade the catalyst when unevenly dispersed. We report a copper-based metal–organic framework (Cu-MOF) grown electrochemically from Cu nanoparticles uniformly anchored on Ti–O–W nanotubular oxides (TWNT@Cu-MOF(ED)). These electrodes were evaluated for the photoelectrochemical degradation of the endocrine disruptors estrone (E1) and 17α-ethinylestradiol (EE2) and compared to spray-coated electrodes prepared with solvothermal Cu-MOF particles (TWNT@Cu-MOF(SC)). TWNT@Cu-MOF(ED) achieved higher degradation efficiencies for both targets, attributable to conformal MOF coverage that minimizes light-blocking and enhances photon utilization. Residual copper-oxide species formed during electrosynthesis further suppressed electron–hole recombination, boosting the formation of reactive oxygen species (•O2–,•OH). Under continuous operation, TWNT@Cu-MOF(ED) maintained stable performance without adsorbent saturation or the need for regeneration, whereas TWNT@Cu-MOF(SC) showed a transient efficiency loss due to contaminant buildup in MOF cavities; activity was fully restored by a brief chronoamperometric regeneration. These findings establish electrochemical deposition as an effective route to integrate MOFs on conductive supports with controlled growth and uniform dispersion, enabling sustained pollutant removal.