Fig. 5: Accelerated CO₂ hydration and sequestration induced by crystalline peptoid assemblies as CA mimics.

A ¹³C single-pulse NMR spectra of the control and Pep12-Zn²⁺ tube solutions saturated with ¹³C -enriched CO₂ at 1 atm. B Normalized ¹³C signal intensity as a function of spin echo delays during ¹³C T₂ measurements showing that T₂ of both CO₂ and bicarbonate are reduced with Pep12-Zn²⁺ tubes. C Time-dependent ¹³C NMR spectra during CO₂ sequestration with 0.1 M CaCl₂ in the control solution and D in the presence of Pep12-Zn²⁺ tubes. E Evolution of concentrations of total bicarbonate (including fully solvated HCO₃⁻ and HCO₃⁻ in ion pairs and clusters) and dissolved CO₂ during CO₂ sequestration with and without Pep12-Zn²⁺ tubes. F A proposed model showing how crystalline Pep12-Zn²⁺ nanotubes function as CA mimics to promote CO₂ hydration as well as the deprotonation of HCO₃⁻ into CO₃² to achieve the accelerated mineralization of CO₂ into stable calcite (CaCO₃) solids.