Study on the Performance of Ti-MOF-Modified Bi₂O₂CO₃ Photocatalyst for the Removal of Organic Matter

In this work, a MIL-125-(Ti)/Bi₂O₂CO₃ (MIL/BOC) composite photocatalyst was fabricated via a facile solvothermal strategy to construct a Z-scheme heterojunction. Comprehensive characterization, including SEM, XRD, XPS, UV-vis diffuse reflectance spectroscopy, PL, EIS, and BET analysis, confirmed the successful integration of MIL-125-(Ti) with BOC and revealed enhanced physicochemical properties of the composite. The photocatalytic performance toward tetracycline hydrochloride (TCH) degradation was systematically evaluated by optimizing catalyst dosage and initial pollutant concentration. The MIL/BOC composite exhibited significantly improved activity compared with pristine BOC, achieving a degradation efficiency of up to 95% for 20 mg·L^-1 TCH. This enhancement is attributed to the synergistic effects of increased specific surface area, improved light absorption, and efficient charge carrier separation. Radical trapping experiments demonstrated that ^•O₂ ^- and h⁺ played dominant roles in the degradation process. With the aid of the GC-MS analysis method, the degradation path of OTC was analyzed. Overall, this study may guide the development of new photocatalysts that respond to visible light and can efficiently remove various organic matter.