Mechanochemical synthesis of gold-silver nanocomposites via diazonium salts

초록

Mechanochemical synthesis of gold-silver nanocomposites from 4-ethynylaryl diazonium tetrachloroaurate(III) salt over chitosan is reported. The nanocomposites (AuAg-CTS NCs, CTS is chitosan) were synthesized by a simple grinding method using an agate mortar and pestle under ambient conditions. Four solid-solid reaction methods were used namely co-reduction, seeding, galvanic exchange, and immobilization. UV-visible data for the nanocomposites showed a peak at 445 nm. Transmission electron microscopy showed variable sizes for AuAg-CTS NCs such as 4.8 +/- 0.9 nm (co-reduction), 74 +/- 24 nm (seeding), 59 +/- 26 nm (exchange), and 11.3 +/- 7 nm (immobilization). X-ray photoelectron spectroscopy measurements supported the formation of gold and silver metals with a peak for Au4f(7/2) at 84.8 eV and Ag3d(5/2) at 368.2 eV.

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