Exploring Real-Time Monitoring of Adsorption Processes at Solid–Liquid Interfaces through Chemical Force Microscopy

Adsorption processes in aqueous environments are critical for understanding pollutant dynamics, assessing ecological risks, and safeguarding human health. Many techniques have been developed to study solid–liquid adsorption including spectroscopic methods. However, there is still a need for supplementary techniques that provide real-time, atomic-scale, and in situ monitoring to achieve a more comprehensive understanding of adsorption mechanisms. Herein, chemical force microscopy (CFM) was utilized to measure hydrophobic interactions to determine the pollutant adsorption at the solid–liquid interface. The hydrophobized probe was employed to ramp onto the adsorbent substrate of interest under aqueous conditions. The forces detected were dependent on the surface adsorption of pollutants on the adsorbent surfaces. From the CFM force–distance curves, adsorption kinetics was obtained for tetracycline and phenol on the graphite surface, which aligned with the results from batch experiments and the in situ streaming potential test. Our findings demonstrate a novel strategy for the real-time interpretation of adsorption processes utilizing CFM that holds the potential to revolutionize studies in environmental interfaces.