Coupling Facet Cu(111)/(100)-Functionalized Graphene Aerogels for a Remarkable Air Disinfection Filter: Extracellular Electron Transfer and the Sharp-Edge Membrane Penetration Effect

As a rising antibacterial material, three different facet-engineered Cu immobilized on a mesoporous rGO(Cu/rGO) aerogel are applied as a filter for air disinfection. Interestingly, the as-synthesized Cu(100/111) nanowire/rGO aerogel (Cu NWs/rGO) exhibits superior activity in air disinfection than Cu(100) nanosphere/rGO and Cu(111) nanoplate/rGO. The experimental characterization and theoretical calculations all confirm that the sharp edges of Cu NWs in Cu/rGO and the light-induced photothermal effect can collectively result in the permeability of the cellular membrane, while Cu NWs/rGO with more defective sites, enhanced electromagnetic field strength, excellent electronic structure, and photothermal ability is beneficial to the generation of reactive oxygen species (ROS) (center dot OH, center dot O-2(-), and O-1(2)). Synergism between the physical and chemical effects can enhance the destruction of cell membranes and then accelerate ROS penetration, thus enhancing bacterial inactivation. Moreover, linear sweep voltammetry (LSV) and time-dependent Kelvin probe force microscopy (KPFM) verify that extracellular electron transfer (EET) between bacteria and Cu/ rGO can also accelerate bacterial inactivation by disrupting the bacterial redox equilibrium. Finally, a comprehensive inactivation pathway was proposed and verified. This work sheds new light on designing antibacterial materials and building the bactericidal mechanism for air purification.

Automated summary

This study applies three different facet-engineered Cu immobilized on a mesoporous rGO aerogel as an air disinfection filter. The Cu nanowire/rGO aerogel with sharp edges and light-induced photothermal effect exhibits superior activity in air disinfection. The Cu/rGO aerogel with more defective sites, enhanced electromagnetic field strength, excellent electronic structure, and photothermal ability is beneficial to the generation of reactive oxygen species (ROS). The extracellular electron transfer (EET) between bacteria and Cu/rGO can disrupt the bacterial redox equilibrium and accelerate bacterial inactivation.