Electrochemically Shape-Controlled Synthesis of Pd Concave-Disdyakis Triacontahedra in Deep Eutectic Solvent

Concave-disdyakis triacontahedral palladium nanocrystals (C-DTH Pd NCs) bound with 120 {631} high index facets were prepared by electrochemically shape-controlled method in deep eutectic solvent (DES). It has found that both the adsorption of urea derived from EDS and the upper (En) and lower (EL) limit potentials of the square-wave potential applied in the synthesis are contributed synergetically in controlling the shape of Pd NCs. The formation of C-DTH Pd NCs with well-defined shape was achieved by the dynamic interaction between urea adsorption at Eu and growth at EL. In situ FTIR spectroscopic studies revealed that the urea adsorbates at Eu play a crucial role in shape evolution, especially in the formation of C-DTH Pd NCs. It has demonstrated that the as synthesized C-DTH Pd NCs enclosed by {631} high-index facets exhibit higher electrocatalytic activity than Pd NCs with other shapes bound by {111} low-index facets (octahedral (OH) and icosahedral (IH)) toward ethanol electrooxidation in alkaline medium.