Interface engineering of Z-scheme MoO3-x/g-C3N5 heterojunction for efficient and rapid degradation of multiple organic dyes

To address the critical bottlenecks of low carrier separation efficiency and insufficient redox potential in nitrogen-rich graphitic carbon nitride (g-C 3 N 5 ), this study developed an environmentally friendly MoO 3-x /CN composite material enriched with oxygen vacancies via a synergistic hydrothermal-calcination protocol. In photocatalytic degradation experiments, the MoO 3-x /CN-0.5 composite exhibited ultra-rapid degradation kinetics and broad-spectrum applicability, achieving degradation rates of 86.91 % for methyl orange (MO), 81.92 % for methylene blue (MB) and 97.11 % for rhodamine B (RhB) within 10 min, significantly outperforming other reported photocatalysts. Distinguishing from other photocatalysts, the exceptional photocatalytic degradation efficiency and broad-spectrum applicability of the MoO 3-x /CN-0.5 composite originate from three synergistic factors: enhanced visible-light absorption, a rationally designed Z-scheme heterojunction, and N-Mo bonds at the phase interface. These structural features synergistically enable efficient electron-hole pairs dissociation, improve the material's redox capability, and preserve structural integrity. This work provides a facile strategy for the controlled synthesis of g-C 3 N 5 -based heterojunctions and expands their application potential for highly efficient photocatalytic degradation.