Fig. 4: Effect of surface chemistry on nucleation behavior of CaCO₃ on hBN and graphene surface.

DFT simulated charge distribution on A hBN and B graphene surfaces. Blue and red spheres in A represent boron and nitrogen atoms, respectively. Silver, light blue, and light red spheres in B represent carbon atoms (Supplementary Fig. 7). The edge of both hBN and graphene flakes are passivated with H atoms; DFT simulated interaction of H₂O, Ca²⁺, CO₃²⁻, and CaCO₃ with C hBN and D graphene surface (Supplementary Fig. 11); E DFT calculated distance between water and surface, between water molecules, and between solutes (Ca²⁺, CO₃²⁻, or CaCO₃) and hBN or graphene surfaces. Gra: graphene; F Minimum energy needed for a Ca²⁺ ion to penetrate the hydration layer on hBN and graphene surface calculated by DFT. Detailed calculation and simulation processes and results can be seen in Supplementary Note 4. G–I The formation of hydration layer on hBN and graphene surface characterized by QCMD. G QCMD experimental setup. PC: personal computer; H Frequency and dissipation change on hBN and graphene surfaces with changes in gas flow humidity; I The effect of gas flow humidity on average frequency decrease and the absolute ratio of dissipation change over frequency decrease (|ΔD/ΔF|).