fig12

Figure 12. (A and B) SEM images of the pristine and 500 °C-air-1 h treated samples; (C) HRTEM image of the 500 °C-air-1 h sample; (D) Defect formation energies in ZnS vs. Fermi level for CZn, CS, CO, and C_Zn-Ns/C_Zn-NO defects; (E) Density of states for defect-free ZnS: Zn d-states (red), S/O p-states (blue), and C p-states (green); (F) Band alignment of ZnS and ZnO defects vs. RHE at pH 7 (band gaps: ZnS, 3.77 eV; ZnO, 3.40 eV), showing CS⁰ (ZnS), CZn⁰ (ZnO), and C₂ + Zn (ZnO) defect levels. (G) H₂ generation time course under UV light with Na₂S/Na₂SO₃ as donors, and (H) total H₂ produced. Copyright 2021, Elsevier^[44]. SEM: Scanning electron microscope; HRTEM: high-resolution transmission electron microscopy; UV: ultraviolet.