Revealing Dominant Oxidative Species in Reactive Oxygen Species-Driven Rapid Chemical Etching.

Reactive oxygen species (ROS) widely participate in a variety of chemical reactions in biological and chemical applications. However, due to the extremely short lifetime of most ROS, conventional ROS-detecting techniques cannot show real-time dynamic changes of ROS-driven chemical reactions and identify the actual role of individual reactive species in these reactions. Herein, using liquid cell TEM complemented by experiments, we directly visualize ROS-driven rapid etching of Prussian bule (PB) in real time and identify the dominant reactive species in etching processes. The results reveal that highly oxidative OH is the dominant reactive radical in ROS-driven rapid chemical etching and hollow mesoporous PB nanoparticles can be synthesized on a minute-level time scale via OH-dominated rapid etching. This work provides insight into ROS-related oxidation, which can continuously improve our understanding of ROS chemistry and make ROS more widely applicable in advanced chemical etching.