Fabrication, characterization, and photocatalytic performance of exfoliated g-C3N4-TiO2 hybrids

A series of TiO2 hybrids composited with exfoliated g-C3N4 nanosheets (CNs) were successfully synthesized through a facile sol-gel method and fully characterized by X-ray diffraction patterns (XRD), Fourier transform-infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UV-vis diffuse reflectance spectra (UV-vis DRS). The CNs-TiO2 hybrids were exposed to visible light irradiation and showed much higher catalytic capability toward degrading dye rhodamine B (RhB) comparing with bare TiO2 and N-TiO2. The sample CNs-TiO2-0.05 exhibited the largest apparent reaction rate constant among all CNs-TiO2 hybrids, which was 2.4 times and 7.0 times as high as bare TiO2 and N-TiO2, respectively. The enhanced catalytic efficiency could be mainly attributed to the well-matched band gap structure with heterojunction interface, suitable specific surface area, and favorable optical property. In addition, active species trapping experiments were conducted, revealing that photoinduced holes (h+) had a severe influence on catalytic outcome, through which a possible catalytic mechanism was finally realized and proposed.