Photo-assisted catalytic reduction performance of three noble metal nanoplatforms (Ag NPs, Pt NPs, Au NPs) and its correlation with the heterostructural properties: Probe sonication fabrication

In this study, three types of noble metal nanocatalysts (Pt NPs, Au NPs, and Ag NPs) were prepared using a green and environmentally safe method - ultrasound probe method - based on the polyol approach. The reduction of metal ions was carried out in two reduction stages: simple and strong reduction. Physicochemical characterization was carried out using a set of relevant and important techniques. The results of the crystal phase study revealed that the pure crystal phases of the three catalyst particles belong to the FCC system, with accurate crystallographic parameters (crystallite size, crystallinity degree, and orientation degree). The results of the aforementioned study were consistent with the results of the elemental analysis. The investigation of these parameters confirmed that the Pt and Ag nanocatalyst particles were built from perfectly crystalline nuclei. While the Au nanocatalyst particles were unique in their crystalline characteristics, demonstrating that their crystal structure was formed from primary crystalline nuclei, unlike the other two catalyst particles. Not only did the three nanocatalyst particles share spherical morphologies, but the Au and Pt nanocatalyst particles also possessed polygonal and sheet morphologies, unlike Ag NPs. To exploit these structural differences, the photoreduction catalytic performance of them was determined in the presence of sodium borohydride on two groups of contaminants: the first group, colored-based contaminants (methylene blue and rhodamine B), and the second, petroleum-based contaminants (p-nitrophenol and trichlorobenzene) at different concentrations. The catalytic yields of the colored contaminants were significantly higher than those of the petroleum-based contaminants. Ag NPs exhibited the highest photoreduction catalytic potential compared to Pt NPs and Au NPs. After conducting reusability tests for each nanocatalyst individually, the green property of all three nanocatalysts demonstrated that they can be reused multiple times and offer superior performance.