Synthesis of Porous TiO2/g-C3N4 Nanocomposites with Enhanced Visible-Light Photocatalytic Properties

A network structured porous g-C3N4 with TiO2 nanoparticles uniformly loaded on the surface was fabricated by a simple hydrothermal method. X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectroscopy and photoluminescence spectroscopy (PL) were adopted to analyze the structure-property relationship of samples. The results show that the formation of network pore structure in g-C3N4 matrix is mainly induced by the protonation of base functionalities (-C-N-), which is highly dependent on the concentration of Ti(SO4)(2) aqueous solution. The uniformly and close interface between these two components is favorable for the highly efficient interparticle electron transfer, therefore achieving enhanced photocatalytic properties. However, the loading of TiO2 nanoparticles on the surface of g-C3N4 leads to the decrease of the visible-light response ability. Therefore, under the joint action of these factors, the porous TiO2/g-C3N4 nanocomposites achieve the best photocatalytic activity when the mole ratio of TiO2:g-C3N4 reaches 1:3, and the visible-light photocatalytic activity of TiO2/g-C3N4 nanocomposite is about as 11.1 times high as that of pure g-C3N4 without modification.