Photoelectrocatalytic bacterial inactivation of Acinetobacter baumannii on Cu2O/TiO2@Cu mesh photoanodes

Abstract

A hybrid Cu₂O/TiO₂ composite loaded on a Cu mesh (Cu₂O/TiO₂@Cu mesh) was developed via a supercritical solvothermal route. A uniformly distributed Cu₂O/TiO₂ p–n hetero-junction was stably coated on a Cu mesh, benefiting the visible-light harvesting. In comparison to electrochemistry and visible-light photocatalysis, the photoelectrochemistry process on the photoanode of the Cu₂O/TiO₂@Cu mesh presented improved bacterial inactivation activity for Acinetobacter baumannii. By means of the main active species of ˙O₂⁻ radicals, the photoelectrocatalytic process on the Cu₂O/TiO₂@Cu mesh also realized complete leakage of K⁺ ions, much stronger mineralization of the cell membrane and more efficient elimination of the self-recovery function, finally leading to cell death. In comparison, the electrochemistry process only led to the leakage of K⁺ ions without inactivation of bacteria, and the visible-light photocatalysis process induced partial leakage of K⁺ ions and cell mineralization after the death of most bacteria.