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.