Effect of Graphene Oxide on the Crystallization of Calcium Carbonate by C₃S Carbonation

The effect of graphene oxide (GO) on the crystallization of calcium carbonate (CaCO₃) is explored in this paper. Precipitation of CaCO₃ was carried out by bubbling carbon dioxide (CO₂) through tricalcium silicate (C₃S) hydration solution with different graphene oxide admixture contents (0.2%, 1% and 2% mass ratios based on C₃S). The polymorph, morphology, crystal size and particle size of CaCO₃ were evaluated using X-ray diffraction (XRD), an environmental scanning electronic microscope (ESEM), and laser particle size analysis. The results showed that addition of GO was able to promote the conversion of CaCO₃ to a calcite crystal phase with higher thermal stability and crystallinity than the control. However, as the dosage of GO increased, the growth of the calcite crystal particles was somewhat suppressed, resulting in a decrease in the crystal particle size and a narrow particle size distribution. When the amount of GO was 0.2%, 1% and 2%, the crystal size of the calcite was 5.49%, 12.38%, and 24.61% lower than that of the sample without GO, respectively, while the particle size of the calcite also decreased by 17.21%, 39.26%, 58.03%, respectively.