Tip-induced electronic polarization at the atomic scale: a mechanistic framework for enhanced hydrolytic bond cleavage

Abstract

Tip effect exhibits unique advantages in a variety of application scenarios covering both civilian and cutting-edge fields.However, the further development of conventional tip-based structures is restricted intrinsically due to strong multi-physical field coupling that enabling miscellaneous thermal-mechanical-electromagnetic interactions. Herein, a single-atom tip structure (SATS) model is proposed through accurate density functional theory (DFT) based on symmetry breaking and quantum confinement effects. We successfully demonstrate the powerful capability of SATS in modulating local charge density, and further predict the enormous potential of copper SATS in promoting the catalysis of water dissociation.Specifically, the hydrolytic bond cleavage can be enabled at a mild temperature (350 K) owning to the reduced dissociation barriers adjacent to copper SATS, which is ascribed to both charge-injection induced intense local fields and core-shell electronic configuration. The abnormal homogenization occurring once the atomic layers of SATS reach to certain level further indicates the unique mechanism of SATS effect compared to the common behavior of macroscopic charge distribution that is solely correlated to curvature. This work provides theoretical basis for breaking the shackle upon the low efficiency and yield of water dissociation via a design principle of quantum-confined electrocatalysts. In addition to the anticipated breakthrough in water harvesting, the strategy of atomic-scale tip engineering can also be extended to similar fields such as photocatalysis, electronic structure regulation, matter transport or capture, etc.