Flash-Thermal Shock Synthesis of Single Atoms in Ambient Air

Single-atom catalysts feature interesting catalytic activity toward applications that rely on surface reactions such as electrochemical energy storage, catalysis, and gas sensors. However, conventional synthetic approaches for such catalysts require extended periods of high-temperature annealing in vacuum systems, limiting their throughput and increasing their production cost. Herein, we report an ultrafast flash-thermal shock (FTS)-induced annealing technique (temperature > 2850 degrees C, <10 ms duration, and ramping/cooling rates of similar to 10(5) K/s) that operates in an ambient-air environment to prepare single-atom-stabilized N-doped graphene. Melamine is utilized as an N-doping source to provide thermodynamically favorable metal-nitrogen bonding sites, resulting in a uniform and high-density atomic distribution of single metal atoms. To demonstrate the practical utility of the single-atom-stabilized N-doped graphene produced by the FTS method, we showcased their chemiresistive gas sensing capabilities and electrocatalytic activities. Overall, the air-ambient, ultrafast, and versatile (e.g., Co, Ni, Pt, and Co-Ni dual metal) FTS method provides a general route for high-throughput, large area, and vacuum-free manufacturing of single-atom catalysts.

Automated summary

This paper reports an ultrafast flash-thermal shock (FTS)-induced annealing technique for the preparation of single-atom-stabilized N-doped graphene in an ambient-air environment. The method offers advantages such as high throughput, large area, and vacuum-free manufacturing of single-atom catalysts. Experimental results demonstrate that the single-atom-stabilized N-doped graphene produced by this method exhibits excellent chemiresistive gas sensing capabilities and electrocatalytic activities.