Fabrication and photocatalytic performance evaluation of hydrodynamic erosion–resistant nano-TiO2–silicone resin composite films

Herein, we present the preparation of nano-TiO2–silicone resin composite films by double liquid phase spray deposition. The films exhibit better adhesion stability and photocatalytic activity under a hydrodynamic erosion condition than conventional nano-TiO2 composite films. The TiO2 layer morphology and effective TiO2 coverage ratio (CR) were affected by the initial curing time (ICT) of the silicone resin, e.g., the increase in an ICT from 10 to 40 min resulted in a CR change from 79.1 to 98.7%. The surface morphology evolution of composite films was studied under a hydrodynamic erosion period of 4 weeks. Obtained results allowed the 4-week evolution to be divided into four stages (pitting, crack pregnant, banded stripping, and surface stripping periods), additionally revealed that the CR of all samples was remained above 65%. The photocatalytic activity of composite films before and after 4-week hydrodynamic erosion was evaluated by rhodamine B degradation experiments. The 4-week erosion only led to the decrease of the photodegradation efficiencies by less than 40% in all cases. Thus, the fabricated TiO2–silicone composite films demonstrated excellent durability and photocatalytic activity under the conditions of long-term hydrodynamic erosion, allowing one to conclude that this work paves the way to the fabrication of next-generation photocatalytic materials for industrial applications.