Realising highly efficient sonodynamic bactericidal capability through the phonon-electron coupling effect using two-dimensional catalytic planar defects.

Conferring catalytic defects in sonosensitizers is of paramount importance in reinforcing sonodynamic therapy. However, the formation of such zero-dimensional (0D) defects is governed by the Schottky defect principle. We herein design two-dimensional (2D) catalytic planar defects within Ti 3 C 2 sheets to address this challenge. These specific planar slip dislocations with abundant Ti 3+ species [Ti 3 C 2 -SD(Ti 3+ )] can yield surface-bound O due to the effective activation of O 2 , thus resulting in a substantial amount of 1 O 2 generation and the 99.72% ± 0.03% bactericidal capability subject to ultrasound (US) stimulation. We discover that the 2D catalytic planar defects can intervene electron transfer through the phonon drag effect - a coupling effect between surface electrons and US-triggered phonons - that simultaneously contributes to a dramatic decrease in O 2 activation energy from 1.65 to 0.06 eV. Our design has achieved a qualitative leap in which the US catalytic site has transformed from 0D to 2D. Moreover, we reveal that the electron origin, electron transfer, and visible O 2 activation pathway triggered by US can be attributed to the phonon-electron coupling effect. After coated with neutrophil membrane (NM) proteins, the NM-Ti 3 C 2 -SD(Ti 3+ ) sheets further demonstrate a 6-log 10 reduction in methicillin-resistant Staphylococcus aureus burden in the infected bony tissue. This article is protected by copyright. All rights reserved.