“…It was indicated that the calcium carbonate formed in the blank is calcite, and the 104 crystal plane is its main growth surface. For the calcium carbonate crystals formed in the solution containing carbon nanoparticles, most of the diffraction peaks of calcite disappeared and the characteristic peaks of aragonite appeared at 26.1°, 27.1°, 33.0°, 36.0°, 37.8°, 38.5°, 42.8°, 45.7°, 48.3°, 50.1°, 52.3°, and 52.9° corresponding to the (111), (021), (012), (200), (031), (112), (220), (221), (202), (132), and (231) crystal faces of aragonite [ 32 , 41 , 42 ]. This indicates that the presence of carbon nanoparticles transformed the main crystal form of calcium carbonate from calcite to aragonite, which is consistent with the SEM and FTIR results.…”