Adsorption of Colloidal Nanoparticles to Supports: Employing Electrostatic Charge Screening and Barrierless Self-Assembly as Nanointegration Strategy.

Abstract

Surfactant-free nanoparticles can be adsorbed on a support material by electrostatic deposition which requires electrostatic attraction between the nanoparticles and the support material. However, when nanoparticles and support have a similar isoelectric point (IEP), it is difficult to create such electrostatically attractive conditions and trigger the adsorption process by pH adjustment. In this work, we present an alternative approach to support laser-generated metal nanoparticles by controlled precipitation onto thin graphene oxide (GO) nanosheets via a kinetically barrierless process induced by high ionic strength. This enables supporting the nanoparticles on the GO sheets with a uniform distribution even though they share a similar IEP. The broad applicability of this method is demonstrated by using different metals, nanoparticle diameters, and mass loadings. In summary, this approach allows supporting nanoparticles regardless of their surface charge.