Effective mineralization and detoxification of tetracycline hydrochloride enabled by oxygen vacancies in g-C3N4/ LDH composites

Development of efficient nanomaterials for photocatalytic degradation is very important in the removal of organic pollutants from water. The oxygen vacancy-rich g-C 3 N 4 / LDH composites (g-C 3 N 4 /LDH-OVs) with a layered structure was prepared for the efficient photocatalysis degradation and mineralization of tetracycline hydrochloride (TC) under visible light irradiation. Oxygen vacancies in the composites achieved through structural induction strategy not only provide abundant active sites but also improve the separation efficiency of the photo-generated carriers, thereby enhancing the degradation and mineralization of TC, as revealed both by theories and experiments. The optimized g-C 3 N 4 /LDH-OVs have achieved excellent photocatalytic activity (i.e., 95 % degradation and 28 % mineralization of TC after 60 min of visible light irradiation), which was 2.3 and 3.5 times higher than that of the pristine g-C 3 N 4 and LDH-OVs, respectively. Furthermore, experimental results based on bio-acute toxicity show that the g-C 3 N 4 /LDH-OVs/Vis system can effectively detoxify the transformation products. This study provides an insight into the development of LDH-based photocatalysts, so as to realize photocatalytic mineralization and simultaneous detoxification through the new strategy of oxygen vacancy defect engineering.