High visible-light photocatalytic hydrogen evolution of C,N-codoped mesoporous TiO2 nanoparticles prepared via an ionic-liquid-template approach

A simple and novel method was developed to fabricate carbon and nitrogen codoping mesoporous TiO2 (CNMT-x) through evaporation induced self-assembly by using an ionic liquid simultaneously as carbon, nitrogen sources and a mesopore creator. These CNMT-x samples were fully characterized by a series of spectroscopic and analytical techniques, such as small- and large-angle X-ray diffraction (XRD), N2 adsorption–desorption isotherms, transmission electron microscopy (TEM), Raman, ultraviolet–visible (UV–vis) diffuse reflectance and X-ray photoelectron (XPS) spectroscopies. The obtained results showed that CNMT-0.75 catalysts exhibited the optimal photocatalytic hydrogen generation activity in water/methanol sacrificial reagent system under visible light irradiation, which was highly superior to those of conventionally prepared C-doped and commercial TiO2. The superior photocatalytic performances observed for CNMT-x could be attributed to the synergistic effects of C,N-codoping with high surface area of mesostructured TiO2.