Laser-fabricated core-shell Cu/Zn-based photocatalytic films with superhydrophilic self-cleaning properties

In this study, superhydrophilic Cu/Zn-based photocatalytic films with core-shell structures were successfully fabricated using a simple and efficient two-step laser deposition technique in air. By adjusting the laser processing parameters, the composition of the films was modified, thereby optimizing their photocatalytic properties. The metal oxide core-shell structures have particle sizes of less than 20 nm. These ultra-small nanoparticles enhance the specific surface area and active sites, thereby promoting the photocatalytic reaction. The experimental results demonstrated that the optimized sample degraded as much as 94.2 % of methyl orange solution (MO) within 40 hours and 100 % of methyl stearate (MS) within 12 hours under 50 W-UV lamp irradiation. It also degraded MO solution inside a vial completely placed outdoors within 4 days, a result rarely reported. Furthermore, the film demonstrated high transmittance of > 83 % at 550 nm, excellent antifogging and self-cleaning properties. Notably, the sample maintained a 0° water contact angle for up to two months under harsh outdoor conditions, a result that has not been previously reported. These properties highlight the broad potential of this laser deposition technique for environmental applications.