RGO/PDA/Bi12O17Cl2-TiO2 composite membranes based on Bi12O17Cl2-TiO2 heterojunctions with excellent photocatalytic activity for photocatalytic dyes degradation and oil-water separation

In the study, the reduced graphene oxide/graphitic Bi12O17Cl2-TiO2 heterojunctions sheet membrane(RGO/PDA/Bi12O17Cl2-TiO2) was fabricated by the dopamine modification and assembling the RGO/PDA/Bi12O17Cl2-TiO2 composites on the surface of commercial CA(cellulose acetate) membrane to degrade methylene blue (MB) and p-chlorophenol (4-CP) to harmless products. These membrane materials were comprehensively characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectra (DRS). The results showed that RGO/PDA/Bi12O17Cl2-TiO2 nanofiber membrane exhibited extremely high degradation performance with a good distribution of RGO/PDA/Bi12O17Cl2-TiO2 on the CA nanofiber membrane surface. Besides, the complete photodegradation of 100 mL MB (15 mg L-1) solution and 100 mL 4-CP (15 mg L-1) solution with artificial visible-light was achieved after 100 min and 160 min, respectively. The RGO/PDA/Bi12O17Cl2-TiO2-CA composite membrane revealed the ability of continuous and simultaneous flow-through separation of oil/water emulsion and degradation of soluble organic dye under visible-light irradiation in a short time. Moreover, the nanofiber membranes exhibited excellent stability and reusability for MB-containing oil-water mixed emulsion separation has great potential to be applied in industrial application.