Visible-light driven degradation of tetracycline hydrochloride and 2,4-dichlorophenol by film-like N-carbon@N-ZnO catalyst with three-dimensional interconnected nanofibrous structure.

The emergence of more and more persistent organic molecules as contaminants in water simulates research towards the development of more advanced technologies, among which photocatalysis is a feasible choice. However, it is still challenging to design a photocatalyst that fulfills all the requirements for industrial application, i.e., active under visible-light irradiation, shape with handy convenience, highly uniform distribution of active sites, substrate with excellent electronic properties, etc. In this study, we report an attempt to solve these issues at once by designing a film-like photocatalyst with uniform distribution of nitrogen-doped ZnO nanoparticles along nitrogen-doped carbon ultrafine nanofibers with three-dimensional interconnected structure. Under visible-light irradiation, the product exhibited remarkable reactivity for the degradation of two model pollutants tetracycline hydrochloride and 2,4-dichlorophenol within 100 min. The cyclic experiments demonstrated only a slight loss (ca. 5 %) of reactivity after five consecutive photocatalytic reactions. We also investigated the detailed relationship between the structural features and the superior properties of this product, as well as the degradation mechanisms. The convenient shape of the product with excellent performances for the treatment of real polluted water increases its suitability for larger scale application. Our work provides a rational design of photocatalysts for environmental remediation.