Organic Molecules Induce the Formation of Hopper-Like NaCl Crystals under Rapid Evaporation As Microcatalytic Reactors To Facilitate Micro/Nanoplastic Degradation

As representative examples of inorganic ionic crystals, NaCl and KCl usually form cubes during the natural evaporation process. Herein, we report the hopper-like NaCl and KCl crystals formed on the iron surface under rapid vacuum evaporation aided by organic molecules. Theoretical and experimental results indicate that it is attributed to the organic molecules alternating adsorption between {100} and {110} surfaces instead of adsorbing a single surface, as well as the fast crystal growth rate. Following this law, we found hopper-like crystals formed under natural evaporation conditions in salt lake crystals as well as synthesized kilogram-class hopper-like crystals. Interestingly, the hopper-like crystals can act as microcatalytic reactors to efficiently facilitate micro/nanoplastic degradation with ∼91.72% styrene yield, highly decreasing the degradation temperature from ∼400 to ∼275 °C. These findings provide an understanding of the growth mechanism of various crystals and a friendly environmental, low-carbon, and economical microcatalytic reactor for efficient micro/nanoplastic degradation.