Construction of novel fluorescent synergistic photocatalytic double Z-scheme photocatalyst for efficient antifouling of polydimethylsiloxane coatings

It has been challenging to enhance the static antifouling (AF) performance of silicone AF coatings using low-cost, high-performance, and environmentally friendly materials. In this work, a graphite-phase carbon nitride/titanium dioxide nanotubes/Sr2MgSi2O7:(Eu2+, Dy3+) long afterglow powder (g-C3N4/TNTs/SLAP, CTS) ternary double Z-scheme heterostructure photocatalyst was designed based on the application of photocatalytic technology in the field of AF and environmental remediation and the function of fluorescent corals and Watasenia scintillans emitting fluorescence to prevent the adhesion of fouling organisms. Then, this composite photocatalyst was dispersed in polydimethylsiloxane resin (PDMS) to prepare g-C3N4/TNTs/SLAP/PDMS (P-CTS) biomimetic fluorescent synergistic photocatalytic AF coating. The double Z-scheme heterostructure formed between the CTS enhances the carrier separation and transport efficiency, thus conferring excellent visible light photocatalytic activity on the CTS. At the same time, the fluorescence emitted by SLAP as a “light store” at night not only prolongs the photocatalytic activity but also inhibits the adhesion of fouling organisms. The results showed that the minimum attachment rates of S. aureus, E. coli, and benthic diatoms of P-CTS were 1.65 %, 1.40 %, and 10.20 %, respectively, under simulated natural diurnal conditions. This novel biomimetic fluorescent synergistic photocatalytic AF coating has good potential applications in marine AF and environmental remediation.