Deep vacancy induced low-density fluxional interfacial water

TL;DR

This study reveals that deep oxygen vacancies in anatase TiO2 significantly alter the structure and flexibility of interfacial water, emphasizing long-range defect effects on solid-liquid interfaces.

Contribution

It introduces a novel understanding of how subsurface oxygen vacancies induce fluxional, low-density interfacial water structures on anatase TiO2 surfaces.

Findings

Deep oxygen vacancies cause reduced contact layer density.

Interfacial water exhibits increased flexibility due to subsurface defects.

Long-range effects of deep defects are crucial for interface behavior.

Abstract

Interfacial water on transition metal oxides such as TiO$_2$ has been widely studied because of their structural complexity and scientific relevance in e.g. photocatalysis and ice growth. Using ab initio molecular dynamics, we find that interfacial water on anatase (101) surface features an unconventional fluxional structure with reduced contact layer density. The density reduction and flexibility of interfacial water are induced by oxygen vacancy defects deeply located in the subsurface. Our study proposes a fresh perspective of the anatase/water interface, raising the importance of non-trivial long-range effects caused by deep defects. These often-neglected effects highlight the necessity and challenges of the state-of-the-art simulation and experimental probing of solid liquid interfaces.