Design of Ti 3 C 2 ZnOAlN ternary nanocomposite for photocatalytic antifouling: a first-principle study

Photocatalytic antifouling has been proved to be an efficient method to restrain marine biofouling. In this work, a new photocatalyst with superior photocatalytic performance was designed based on first-principle calculation. Two-dimensional (2D) zinc oxide (ZnO) and aluminum nitride (AlN) based on (001) crystal plane were selected to construct the new catalyst, which could effectively adjust their band gap and band edge alignment. However, the stress and strain under lattice distortion would damage their direct band gap characteristics, even affecting their stability. To eliminate these effects, titanium carbide (Ti3C2) MXenes was used as substrate to carry 2D-ZnO and 2D-AlN (Ti3C2ZnOAlN), in which Ti3C2 played as a co-catalyst. The results reveal that the designed composite structure has a low work function and is a type II heterostructure, which can achieve the separation of photo-generated electrons and holes efficiently. The phonon frequency comparison results indicate that participation of Ti3C2 greatly improves the dynamic stability of the structure. An asymmetric built-in electric field at the interface further reduces the work function and is considered to be the main reason for the rapid migration of carriers in the direction of the interface. At the same time, the light absorption peaks in the Ti3C2ZnOAlN composite structure are red-shifted and produce a high coincidence with the main irradiation intensity of solar flux. The triple interfaces are also helpful to improve the utilization of incident photons in all directions. According to the results of the band edge position and Nernst equation, it can be concluded that the Ti3C2ZnOAlN composite material can meet the ROS reaction conditions under any pH environments, so it should be an environmentally adaptable photocatalytic sterilization material for antifouling.