Ultrafast Generation of Nanostructured Noble Metal Aerogels by a Microwave Method for Electrocatalytic Hydrogen Evolution and Ethanol Oxidation

As a self-supporting three-dimensional material, noble metal aerogels (NMAs) have attracted significant attention because of their large specific surface area, high porosity, and excellent catalytic activity, exhibiting satisfactory achievements in various fields. However, the preparation process of NMAs is costly and time-consuming, in addition to requirement of high concentration of precursors, complicated procedure, and uneven size of ligaments of NMAs. Although the favorable morphology and size characteristics endow them with broad application prospects, the above-mentioned problems have always been a huge obstacle to their development. Here, considering that the microwave and heating functions are available at the same time, we propose a synthesis method adopting the microwave heating process to prepare NMAs at an ultrafast speed. It only takes 10 s to get NMAs (including single-metal, bimetal, and trimetal-based NMAs), successfully gelling in a very wide initial salt concentration range (2.0 mu M-6.25 mM), the first time to enter micromolar art. In addition, the size of aerogels has also been well controlled, especially the alloy aerogels, all of which have reached the scale below 10 nm. Moreover, it was found that the nanostructured NMAs exhibit outstanding electrocatalytic performance in the hydrogen evolution reaction and ethanol oxidation reaction. This undoubtedly provides a convenient way for the ultrafast and efficient preparation of nanostructured NMAs and also opens up a broader field for the development of electrocatalysts.