Strain engineering of ZrS ₂ /g-C ₃ N ₄ heterojunction photocatalyst for building environmental remediation: Theoretical calculations

Abstract To enhance the overall performance of optoelectronic devices and catalytic systems, developing high-performance heterojunction materials has become an important materials design strategy. In this study, g-C3N4 and ZrS2 were used to construct binary and ternary heterojunctions (ZrS2/g-C3N4 (M1), ZrS2/g-C3N4/ZrS2 (M2), and g-C3N4/ZrS2/g-C3N4 (M3)), and their electronic structural characteristics and photocatalytic performance in building environment remediation were systematically investigated. The computational results reveal that the bandgap energies for M1, M2, and M3 are 1.441 eV, 1.427 eV, and 1.393 eV, respectively. Application of biaxial strain effectively modulates the bandgap magnitude and enhances light absorption properties, while preserving the direct bandgap character of the heterojunctions. Notably, the M3 heterojunction demonstrates the most pronounced interlayer charge transfer, quantified as 0.73 |e|. Furthermore, the heterojunctions exhibit a high absorption coefficient of 2.6 × 105 cm-1. The ternary heterojunctions (M2, M3) exhibit lower overpotentials in both the hydrogen evolution reaction and the oxygen evolution reaction. The conclusions of this study provide a theoretical foundation for the development of high-performance materials aimed at the field of building environment restoration.