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

Abstract

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.