Noble Metal Aerogels.

Noble metal-based nanomaterials have been a hot research topic during the past few decades. Particularly, self-assembled porous architectures have triggered tremendous interest. At the forefront of porous nanostructures, there exists a research endeavor of noble metal aerogels (NMAs), which are unique in terms of macroscopic assembly systems and three-dimensional (3D) porous network nanostructures. Combining excellent features of noble metals and the unique structural traits of porous nanostructures, NMAs are of high interest in diverse fields, such as catalysis, sensors, and self-propulsion devices. Regardless of these achievements, it is still challenging to rationally design well-tailored NMAs in terms of ligament sizes, morphologies, and compositions and profoundly investigate the underlying gelation mechanisms. Herein, an elaborate overview of the recent progress on NMAs is given. First, a simple description of typical synthetic methods and some advanced design engineering are provided, and then, the gelation mechanism models of NMAs are discussed in detail. Furthermore, promising applications particularly focusing on electrocatalysis and biosensors are highlighted. In the final section, brief conclusions and an outlook on the existing challenges and future chances of NMAs are also proposed.