Performance tuning and optimisation of 2D–2D-like g-C3N4 modified Bi2O2CO3 n–n homotypic heterojunction as an inactivating photocatalytic material

Semiconductor photocatalysts applied to inactivate marine microorganisms，It has been proved to be an environmentally efficient means of improving the Marine environment. To overcome the problem of limiting light response range causing by the wide bandgap of Bi2O2CO3 photocatalyst, the photocatalytic activity of Bi2O2CO3 was improved by surface modification with the introduction of g-C3N4. In this paper, g-C3N4/BOC heterojunctions were prepared by a convenient general hydrothermal method combining with assisted ultrasonication. The photocatalytic sterilisation activity was also verified under simulated sunlight irradiation. By X-ray diffraction (XRD)、X-ray photoelectron spectroscopy (XPS)、scanning electron microscopy (SEM) and transmission electron microscopy (TEM), it was ensured that the system contains g-C3N4, and g-C3N4 is attached to the outer layer of Bi2O2CO3 flower ball-like microspheres in an irregular nanosheet-like morphology. The 2D–2D heterojunction morphology is formed. By UV-Vis diffuse reflectance spectroscopy (DRS), electrochemical characterization, and photoluminescence spectroscopy (PL). I verified the formation of n-n homotype heterojunction between g-C3N4 and Bi2O2CO3. Compared with Bi2O2CO3 catalyst, the light-induced photogenerated electron-hole pairs of g-C3N4/BOC photocatalyst are separated efficiently. In addition, after 5 cycles of stability tests, the g-C3N4/BOC composite photocatalyst was verified to have good environmental catalytic stability. The 10CNB composite photocatalyst proclaimed the highest photocatalytic sterilization activity, reaching 95%. The catalytic performance is 5 times higher than that of pure BOC photocatalyst and 3.4 times higher than that of pure g-C3N4 photocatalyst. By testing the active substance, the hydroxyl radical (•OH) is a significant contribution to the photocatalytic sterilisation process.