Interfacial Charge Transfer in Defect-Rich Ti₃C₂/BiOIO₃ Heterostructured Photocatalysts for the Degradation of Methyl Orange

Surface defect engineering and heterojunction fabrication are considered to be effective strategies for modifying semiconductor photocatalysts. In this work, we synthesized a series of defect-rich Ti₃C₂/BiOIO₃ nanocomposites for photocatalytic degradation of methyl orange (MO). The samples were characterized by various techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), ultraviolet–visible (UV–vis) spectroscopy, and photoluminescence (PL). The composite exhibited the best photocatalytic performance toward MO under simulated sunlight, which can degrade 95.2% MO in 0.5 h. The total organic carbon (TOC) analysis was also used to ascertain the mineralization degree of MO. The BiOIO₃ light response is widened from UV to the visible light region by generating defect energy levels of I^–. At the same time, the oxygen vacancy (OV) as the negative charge attraction center captures the excited electrons in the conduction band and doping level, and Ti₃C₂ as a cocatalyst transfers electrons. This work provides guidance for designing photocatalysts with high-efficient interfacial charge transfer heterostructures.