Facile Synthesis of ZnO/Ag Nanostructure with Enhanced Photocatalytic Activity

A series of x%Ag/ZnO (x: 0; 1; 2; 5; 10) nanostructures were successfully synthesized through the facile method. The material's structures were confirmed through X‐ray diffraction, while their morphology, elemental distribution, and components were analyzed using cross‐sectional transmission electron microscopy (XTEM), Field‐emission scanning electron microscopy (FESEM). The optical properties of Ag/ZnO revealed a decrease in band gap from 3.2 eV to 2.83 eV and a significant reduction in photoluminescence intensity with increasing Ag nanoparticle loading on the surface of ZnO. The photocatalytic activity of synthesized Ag/ZnO flower‐like nanostructure was evaluated in the photodegradation of methylene blue (MB) under UV‐Vis irradiation. The photocatalytic results indicated that decorating Ag nanoparticles on the surface of ZnO improved the photodegradation of MB. Interestingly, the 5%Ag/ZnO showed the highest effectiveness, achieving a 99% removal efficiency of MB for 60 minutes under UV‐Vis irradiation. Notably, the ultra performance liquid chromatography‐ tandem mass spectroscopy (UPLC‐MS/MS) confirmed the structure of intermediates, while total organic carbon (TOC) removal was 47%. Moreover, the proposed mechanism for the charge transfer process was based on the results of radical scavenging experiments, which showed that superoxide was the dominant reactive species. Finally, the 5%Ag/ZnO was stable and reused at least five times. Ag nanoparticles acted as an electron mediator and localized surface plasmon resonance effect to enhance the photodegradation of Methylene Blue (MB) under UV‐vis irradiation. The mechanism for charge transfer was proposed, as well as the supper radical oxide as the main active species was confirmed based on scavenging experiments. The photodegradation pathway was proposed through UPLC‐MS/MS and TOC results. The Ag/ZnO flower‐like catalyst was robust and could be reused at least five times for MB photodegradation without loss of catalytic activity.