Facet-Dependent Surface Charge and Hydration of Semiconducting Nanoparticles at Variable pH

Description

Understanding structure and function of solid-liquid interfaces is essential for the development ofnanomaterials for various applications including hetero­geneous catalysis in liquid phase processes and water splitting for storage of renewable electricity. The characteristic anisotropy of crystalline nanoparticles is believed to be essential for their performance but remains poorly under­stood and difficult to characterize. Dual scale atomic force microscopy is used to measure electrostatic and hydration forces of faceted semiconducting SrTi􀀌 nanoparticles in aqueous electrolyte at variable pH. The following are demonstrated: the ability to quantify strongly facet-dependent surface charges yielding isoelectric points of the dominant {100} and {110} facets that differ by as much as 2 pH units; facet-dependent accumulation of oppositely charged (SiO2) particles; and that atomic scale defects can be resolved but are in fact rare for the samples investigated. Atomically resolved images and facet­dependent oscillatory hydration forces suggest a microscopic charge genera­tion mechanism that explains colloidal scale electrostatic forces.

Period	3 Feb 2023
Event title	Symposium: Materials for Sustainability, Mat4Sus 2023
Event type	Conference
Location	Delft, NetherlandsShow on map