Liquid/Liquid Interface-Assisted Synthesis of Two-Dimensional Metal Networks with High-Density Planar Defects for Electrocatalysis

A metal nanonetwork with high-density planar defects is an attractive candidate for highly efficient electrocatalysts due to its fast electron transfer capability and abundant active sites. However, its fabrication has met with limited success by far. Herein, we report a liquid/liquid interface-assisted synthesis of two-dimensional (2D) palladium (Pd) networks with high-density planar defects and their superior catalytic performance for the methanol oxidation reaction (MOR). The successful preparation of 2D Pd networks mainly relies on the combination of etching and regrowth of Pd nanocrystals assembled on the water/chlorobenzene interface. Using different metal nanocrystals as the starting materials, we could further extend the method for preparing 2D gold (Au) and palladium–gold (Pd–Au) bimetallic networks. During the MOR, the 2D Pd network could deliver much enhanced activities relative to the pristine nanocubes, with a factor of 3.7 and 2.3 enhancement in specific activity and mass activity, respectively, due to the network structure and high-density planar defects.