Enhanced Fenton-like process over Z-scheme MoO₃ surface decorated with Fe₂O₃ under visible light

Photocatalysts consisting of Z-scheme heterojunctions are commonly used in wastewater treatment due to their exceptional reactivity in photocatalysis and highly efficient visible-light utilization. In this work, Fe₂O₃-decorated MoO₃ rods were synthesized through a two-step method and their photodegradation of methylene blue (MB) was evaluated. The Fe₂O₃/MoO₃ rods were characterized by XRD, SEM, micro-Raman, XPS, UV-Vis DRS, and PL to investigate their structural, morphological, and optical properties. The results indicate that the photodegradation efficiency of Fe₂O₃/MoO₃ improved through a reduction in the gap energy and persistence of a 1D hexagonal prism structure. The degradation rate of MB was enhanced from 31.7 to 91.5% after irradiation for 180 min owing to electron-hole separation and Fenton-like process. Formation of the OH radical is a key factor in the photodegradation reaction and with the addition of H₂O₂ the efficiency can further improve via a Fenton-like mechanism. Furthermore, the Z-scheme mechanism concurrently delineated. The Fe₂O₃/MoO₃ rod composites were also found to retain high photocatalytic efficiency after being reused five times, which may be useful for future applications.