Carbon nitride coupled Ti-SBA15 catalyst for visible-light-driven photocatalytic reduction of Cr (VI) and the synergistic oxidation of phenol

In this study, carbon nitride was loaded into the titanium incorporated SBA-15 mesoporous silica (denoted as Ti-SBA15-CN) by a two-step vapor condensation of dicyandiamide. The as-prepared sample was characterized by various spectroscopy techniques. Photocatalytic reduction of Cr (VI) in aqueous solution was investigated using Ti-SBA15-CN under visible-light irradiation. By introducing Ti into the SBA-15 framework structure, the visible light driven photocatalytic activity of the obtained Ti-SBA15-CN was higher than SBA15-CN and the photocatalytic activity exhibited a rise with the increase of Ti contents. It was because the presence of Ti moiety could promote the separation of the photo-generated charge carriers in carbon nitride, leading to the enhancement of the photocatalytic activity. The addition of phenol further enhanced the photocatalytic reduction of Cr (VI). Similarly, the presence of Cr (VI) promoted the degradation of phenol. The synergistic effect between the reduction of Cr (VI) and the degradation of phenol provided salutary method for purification of the complex waste water and environmental restoration.