Photocatalytic activity of ZnO films with laser-induced dewetted bimetallic NPs: Impact of Au/Pd ratio

This study introduces a novel approach to enhance the photocatalytic activity of ZnO films. By using single-pulsed nanosecond laser irradiation on Au/Pd/ZnO and Pd/Au/ZnO trilayer stacks, deposited by magnetron sputtering, we synthesized well-mixed Au–Pd alloyed nanoparticles (NPs) on a ZnO thin film. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the formation of the bimetallic NPs, and adjusting the layer thickness and stacking order allowed us to control the relative Au and Pd content. Under solar simulated light, we assessed the photocatalytic activity for indigo carmine (IC) dye degradation and found that ZnO films decorated with monometallic Au–Pd NPs exhibited superior performance compared to pristine ZnO and ZnO films with monometallic NPs. The photocatalytic activity was assessed for indigo carmine dye degradation. The optimum bimetallic composition (0.8 Pd, 0.2 of Au) showed a 13.8-fold increase in dye degradation compared to the pristine ZnO film and up to a 7.6-fold improvement over ZnO films decorated with monometallic nanoparticles. This study offers a facile and scalable method for preparing bimetallic NPs on semiconductor films for enhanced photocatalytic applications.