Improving visible-light-induced photocatalytic ability of TiO2 through coupling with Bi3O4Cl and carbon dot nanoparticles

The fabrication of photocatalysts with considerable photocatalytic performance can be the main purpose for the researchers to substitute the traditional wastewater treatment processes. Accordingly, in this work, visible-light-responsive TiO2/Bi3O4Cl/carbon dots (denoted as TO/BOC/CD) photocatalysts were synthesized via simple strategy. Multiple techniques including EIS, photocurrent, XPS, PL, UV-vis DRS, BET, FT-IR, EDX, XRD, HRTEM, and SEM were employed to explore electrochemical, chemical, and physical features of the nanocomposites. The photocatalytic ability of the samples for Cr (VI), methylene blue, fuchsine, and rhodamine B removals was examined to display their widespread capability in removing different pollutants. The optimal photocatalytic performance related to the nanocomposite with 20% of BOC and 1 mL of CD solution (TO/BOC/CD (1 mL) photocatalyst), which was 13.8, 25.9, 14.2, and 52.3-folds as high as the TiO2 and 2.84, 2.26, 2.57, and 5.25-times higher than the TO/BOC (20%) nanocomposite in removals of Cr (VI), methylene blue, fuchsine, and rhodamine B, respectively. The impressive photocatalytic activity of the TO/BOC/CD photocatalysts is ascribed to the betterment of the optical property of the fabricated photocatalysts. With the enhancement CD content, the respective ternary nanocomposites displayed the highest optical absorption in the visible region. The other reasons in improving the photocatalytic activity are related to increased e(-)/h(+) separation capability, and better textural properties. Additionally, trapping experiments demonstrated that the holes and superoxide anion radicals possess a substantial role during the photocatalytic reaction. Thus, this work could promote the potential utilization of TiO2-based photocatalysts for removal of hazardous contaminants under visible light.