Template-Directed Growth of a 3D Hierarchical Structure of Well-Aligned Bimetallic MOF Arrays for High-Efficiency Electrocatalytic Air Sterilization

Bimetallic MOF array has more catalytic active sites, better conductivity and water stability, which shows high efficiency in air disinfection and protects public health. To address increasing concerns regarding environmental air quality, it is highly desirable to develop low-cost and high-efficiency air-sterilization technology. Herein, as a proof-of-concept, a template-directed growth strategy is designed to fabricate a 3D hierarchical superstructure of well-aligned bimetallic metal–organic framework (MOF) arrays. Taking advantage of the designed electrode material (0.3Co-MOF/Cu@Cu), which provides a greater number of catalytically active sites, better conductivity, and water stability in comparison with pure copper mesh, the proposed strategy exhibits high electrocatalytic efficiency for air sterilization. Under an external electric field, the designed electrode can electroporate bacteria, accelerate the electrocatalytic reduction of oxygen adsorbed by oxygen vacancies, and dynamically generate more exogenous reactive oxygen species (ROS), which will increase the negative ion concentration in the air and thereby increase the comfort level for people in the room. Moreover, the free electrons and exogenous ROS on the surface of the material will disturb the physiological activities inside bacteria, resulting in the production of endogenous ROS inside the bacteria and bacterial death. The sterilization rate of 1.5 m∙s −1 of airflow at 2 V (equivalent to a treatment time of 0.0026 s) is as high as 99.51%, demonstrating the great potential of the proposed strategy for practical application.