Sargassum horneri-based carbon-doped TiO2 and its aquatic naphthalene photodegradation under sunlight irradiation

BACKGROUND During the past two decades, aquatic polycyclic aromatic hydrocarbon (PAH) contamination has gained more and more attention, because of carcinogenicity or mutagenicity, toxicity, persistence and bioaccumulation, and a huge threat posed to entire ecosystems. RESULTS Sargassum horneri ( SH )-based carbon was pretreated with ethanol and formaldehyde, and obtained after pre-carbonization using H 2 SO 4 . The SH carbon powder was used to immobilize nano-TiO 2 in aquatic environment by a facile sol–gel method. The resulting C/TiO 2 catalyst was applied to photocatalytic aquatic naphthalene degradation under sunlight and showed the best naphthalene degradation performance of 83.77% under simulated sunlight, which could be attributed to the shape and structure contribution originating from SH . C/TiO 2 served as both adsorbent and catalyst in the degradation process of naphthalene, and the photodegradation process conformed to a double-exponential kinetic model, indicating that there are physical and chemical processes involved in the degradation. The mechanism for enhanced photocatalytic activity was verified as a synergistic mechanism resulting from SH -based carbon and TiO 2 , and showed industrial potential for removal aquatic PAH pollutants. CONCLUSIONS This study verifies that the synergistic effect resulting from SH -based carbon and TiO 2 enhanced the photocatalytic performance. © 2021 Society of Chemical Industry (SCI).