*Article* **Preparation of High-Porosity B-TiO2/C3N<sup>4</sup> Composite Materials: Adsorption–Degradation Capacity and Photo-Regeneration Properties**

**Xiang Guo <sup>1</sup> , Lei Rao 2,\* and Zhenyu Shi <sup>1</sup>**


**Abstract:** Adsorption can quickly remove pollutants in water, while photocatalysis can effectively decompose organic matter. B-TiO2/g-C3N<sup>4</sup> 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-C3N<sup>4</sup> materials was inspected by SEM, TEM, BET, and EDS, and the results showed that close interfacial connections between TiO<sup>2</sup> and g-C3N<sup>4</sup> , which are favorable for charge transfer between these two semiconductors, formed heterojunctions with suitable band structure which was contributed by the molten B2O<sup>3</sup> . Meanwhile, the molten B2O<sup>3</sup> effectively increased the specific surface area of TiO2/C3N<sup>4</sup> materials, thereby increasing the active sites and reducing the recombination of photogenerated electron–hole pairs and improving the photocatalytic degradation abilities of TiO<sup>2</sup> and g-C3N<sup>4</sup> . Elsewhere, the crystal structure analysis (XRD, XPS, FTIR) results indicated that the polar -B=O bond formed a new structure with TiO<sup>2</sup> and g-C3N<sup>4</sup> , 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-C3N<sup>4</sup> composite material were found to be 8.5 times and 3.4 times higher than that of g-C3N<sup>4</sup> . 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.

**Keywords:** adsorption; degradation; B2O<sup>3</sup> ; TiO2/C3N<sup>4</sup> ; molten
