Preparation of High-Porosity B-TiO2/C3N4 Composite Materials: Adsorption–Degradation Capacity and Photo-Regeneration Properties

Abstract

Adsorption can quickly remove pollutants in water, while photocatalysis can effectively decompose organic matter. B-TiO2/g-C3N4 ternary composite photocatalytic materials were prepared by molten method, and their adsorption–degradation capability under visible light conditions was discussed. The morphology of the B-TiO2/g-C3N4 materials was inspected by SEM, TEM, BET, and EDS, and the results showed that close interfacial connections between TiO2 and g-C3N4, which are favorable for charge transfer between these two semiconductors, formed heterojunctions with suitable band structure which was contributed by the molten B2O3. Meanwhile, the molten B2O3 effectively increased the specific surface area of TiO2/C3N4 materials, thereby increasing the active sites and reducing the recombination of photogenerated electron–hole pairs and improving the photocatalytic degradation abilities of TiO2 and g-C3N4. Elsewhere, the crystal structure analysis (XRD, XPS, FTIR) results indicated that the polar -B=O bond formed a new structure with TiO2 and g-C3N4, which is not only beneficial for inhibiting the recombination of electron holes but also improving the photocatalytic activity. By removal experiment, the adsorption and degradation performances of B-TiO2/g-C3N4 composite material were found to be 8.5 times and 3.4 times higher than that of g-C3N4. Above all, this study prepared a material for removing water pollutants with high efficiency and provides theoretical support and experimental basis for the research on the synergistic removal of pollutants by adsorption and photocatalysis.