The ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) is investigated as a solvent for the synthesis of Pd particles. Interestingly, nanosheet-constructed Pd particles could be successfully synthesized in [EMIM]Ac without any additional reducing agent and template under ionothermal conditions. [EMIM]Ac itself works as the solvent, the reducing agent, and the template for the formation of these interesting Pd particles, making this method complementary to the well-known ionic-liquid-precursor approach. Furthermore, [EMIM]Ac can be recycled with no loss of activity for the formation of nanosheet-constructed Pd particles within our studied cycles. Specifically, the nanosheet-constructed Pd particles exhibit superior electrocatalytic activity and stability towards ethanol oxidation and formic acid oxidation compared with commercially available Pd black catalyst, thus demonstrating their promising applications in fuel-cell area. The current approach, thus, presents a green approach towards the synthesis of Pd particles, using only a simple palladium salt and an ionic liquid.

Morphology- and composition-controlled synthesis of Au–Pd bimetallic particles was realized by a facile ionic liquid assisted route at room temperature. The morphologies of the synthesized particles, such as nanoflake-constructed spheres with a core–shell structure, nanoparticle-constructed spheres, and nanoparticle-constructed dendrites, could be well controlled by the present route. The ionic liquid was found to play a key role in the formation of these interesting particles. Moreover, the composition (Au:Pd) of the particles could be modulated by means of the molar ratio of the metal precursors in the feeding solutions. The Au–Pd bimetallic particles exhibit high electrocatalytic activity toward oxidation of ethanol and formic acid. Furthermore, cyclic voltammetric studies on the as-prepared Au–Pd bimetallic particles revealed good electroactivity for H₂O₂, which results in an effective amperometric H₂O₂ sensor.