Single-atom alloys (SAAs) have ignited a surge of unprecedented interest as the advanced nanomaterials and opened many opportunities for wide applications. Herein, 3D porous aerogels comprising ionic liquid (IL) functionalized PdBi SAA building blocks with atomically dispersed Bi on Pd nanowires (IL/ Pd 50 Bi 1 ) are synthesized with accelerated gelation kinetics, which could serve as high-efficiency electrocatalysts for ethanol oxidation reaction (EOR). Benefiting from the unique structures of aerogels including synergistic effects of PdBi SAA nanowire networks and interface engineering, the optimized IL/Pd 50 Bi 1 aerogels display a nearly fourfold enhancement in mass activity and boosted stability for EOR compared to commercial Pd/C. Density functional theory calculations further demonstrate that isolated Bi atoms on Pd nanowire networks decrease the energy barrier of the rate-determining step, resulting in excellent electrocatalytic activity for EOR. This work provides a promising method for developing efficient SAA catalysts for fuel electrooxidation.

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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.

Self‐powered sensing systems (SPSSs) are critical components in smart portable electronic devices. Zinc‐air batteries (ZABs) as promising energy devices provide a great opportunity to develop novel SPSS for sensing applications owing to the merit of high open‐circuit potential. Herein, hierarchically porous single‐atom iridium embedded nitrogen‐doped carbon (SA‐Ir/NC) is reported as an efficient catalyst for the oxygen reduction reaction (ORR) in the neutral ZABs, enabling the SPSSs towards glucose detection with a high sensitivity and stable output signal. The resultant SA‐Ir/NC shows superior ORR activity and stability to commercial Pt/C in neutral electrolytes. According to the theoretical calculations, IrN5 active sites in SA‐Ir/NC exhibit moderate adsorption free energy to reaction intermediates, giving SA‐Ir/NC excellent four‐electron ORR activity and well‐enhanced H2O2 tolerance. When SA‐Ir/NC is applied as an air cathode, the as‐prepared ZABs display a large open‐circuit voltage of 1.42 V, a remarkable power density of 90.4 mW cm−2, and excellent long‐term stability. After being integrated with glucose oxidase, the SPSSs are successfully established for sensitive detection of glucose based on a competitive model, holding great promise in biosensing applications.