Opportunistic use of tetrachloroaurate photolysis in the generation of reductive species for the production of gold nanostructures

Abstract

The photolysis of gold salts is rarely viewed as the initiation for gold nanoparticle (AuNP) formation. Yet, photolysis of AuCl₄⁻ generates chlorine atoms whose rich hydrogen transfer chemistry can readily generate strongly reducing radicals. Interesting precursors include hydrogen peroxide, 2-propanol, 1,4-cyclohexadiene and tetrahydrofuran; all of them yield strongly reducing radicals. Further, this group of substrates has been selected because of the innocuous and volatile nature of reagents and products, thus allowing a remarkably clean synthesis of gold nanostructures. In the case of H₂O₂ the by-products are water and oxygen. The methodology reported here opens the door to particles that can be modified in situ or post-synthesis with custom surface covering without concern for chemical debris from the nanostructure synthesis.