Complementary and synergic effects of microwaves and ultrasound in metal-assisted synthesis

摘要

While synthetic protocols involving metal dispersions' have long been a favourite domain in sonochemistry, the irradiation of metal particles with microwaves has been a forbidden practice because of the risk of arcing and explosion. Modern reactors and suitable procedures under inert atmosphere, make metal-assisted reactions under combined ultrasound-microwave irradiation feasible and safe. The interaction of acoustic and electromagnetic waves with a heterogeneous reaction mixture containing metals usually strongly accelerates the process. Both the hot spots generated by acoustic cavitation and dielectric heating activate the metal surface enhancing its reactivity even with relatively low metal content.