Conversion of CO₂ from Power Plant into CaCO₃ Nanoparticles

Carbon dioxide (CO₂), a main composition of flue gas, represents a significant and largely untapped carbon resource. Herein, mediated by glycine (Gly), we captured and converted CO₂ into CaCO₃ nanoparticles using a real flue gas from a power plant, first time demonstrating the feasibility of using amino acid to convert CO₂ from power plant flue gasses. The method did not require extraneous energy and CaCO₃ nanoparticles with a size of ~25 nm were obtained. Moreover, the potential toxicity of CO₂-converted nanoparticles was investigated. It appeared that both the initial CO₂ loading and the carbamate percentage significantly influence the shape and size of the CaCO₃ particles. Our method was also proved effective for flue gas with varying CO₂ concentrations (4%, 12%, and 20%). By tuning flue gas bubbling time and flow rate to achieve consistent CO₂ loading and carbamate levels, we produced CaCO₃ nanoparticles with similar shapes and sizes across all CO₂ concentrations studied. In addition, our data indicated that although real flue gas contains small amounts of gases like oxygen and CO, they insignificantly influence the shape and size of our nanoparticles but did impact the phase component of CaCO₃. The toxicity experiments found that CaCO₃ nanoparticles produced from both real flue gas and simulated flue gas exhibited concentration- and time-dependent effects on cell viability.