Gold diamond Nanocomposites Efficiently Generate Hydrated Electrons upon Absorption of Visible Light

TL;DR

This paper demonstrates that nanocomposites of detonation nanodiamonds and gold nanoparticles can efficiently generate hydrated electrons upon visible light absorption, potentially advancing solar photocatalysis and environmental applications.

Contribution

It introduces a novel nanocomposite that absorbs visible light to produce hydrated electrons, expanding diamond's utility beyond ultraviolet light.

Findings

Efficient visible light absorption by AuNP@DND nanocomposites.

Generation of hydrated electrons detected at 720 nm.

Plasmonic enhancement via surface sp2 islands facilitates this process.

Abstract

An efficient source of hydrated electrons generated by visible light has the potential to have a major impact on solar homogeneous catalysis. Diamond has potentially a high capability of emitting hydrated electrons, but only using ultraviolet light (lambda<225 nm). In this work, we demonstrate the efficient absorption of visible light by nanocomposites consisting of detonation nanodiamonds and gold nanoparticles (AuNP@DNDs), which subsequently emit electrons into the aqueous environment in which they are suspended. This has been done by exciting the AuNP@DND with visible laser light and monitoring the appearance and intensity of the transient absorption of hydrated electrons centered at around 720 nm. We suggest that this mechanism is made possible by the plasmonic enhancement of visible absorption by sp2-hybridized islands on the DND surface. Optimization of this process could lead to important breakthroughs in solar photocatalysis of energy-intensive reactions such as N2 and CO2 reduction as well as providing a non-toxic source of hydrated electrons for applications in wastewater management and nanomedicine.