Quantitative Structure-Activity Relationship of Nanowire Adsorption to SO2 Revealed by In Situ TEM Technique

A quantitative structure-activity relationship (QSAR) is revealed based on the real-time sulfurization processes of ZnO nanowires observed via gas-cell in situ transmission electron microscopy (in situ TEM). According to the in situ TEM observations, the ZnO nanowires with a diameter of 100 nm (ZnO-100 nm) gradually transform into a core-shell nanostructure under SO2 atmosphere, and the shell formation kinetics are quantitatively determined. However, only sparse nanoparticles can be observed on the surface of the ZnO-500 nm sample, which implies a weak solid-gas interaction between SO2 and ZnO-500 nm. The QSAR model is verified with heat of adsorption (-Delta H degrees) and aberration-corrected TEM characterization. With the guidance of the QSAR model, the following adsorbing/sensing applications of ZnO nanomaterials are explored: (i) breakthrough experiment demonstrates the application potential of the ZnO-100 nm sample for SO2 capture/storage; (ii) the ZnO-500 nm sample features good reversibility (RSD = 1.5%, n = 3) for SO2 sensing, and the detection limit reaches 70 ppb.

Automated summary

Based on real-time observations of ZnO nanowires sulfurization processes in SO2 atmosphere using in situ TEM, a quantitative structure-activity relationship (QSAR) is revealed. The ZnO-100 nm nanowires gradually transform into core-shell nanostructures, while sparse nanoparticles are observed on the surface of ZnO-500 nm sample, indicating weak solid-gas interaction with SO2. The QSAR model is validated with adsorption heat data and aberration-corrected TEM characterization, leading to exploration of adsorbing/sensing applications of ZnO nanomaterials.