Controlled Synthesis of CeO₂NS-Au-CdSQDs Ternary Nanoheterostructure: A Promising Visible Light Responsive...

With the advancement of promising multifaceted powdered photocatalytic systems, problems related to environmental pollution and energy requirements have been addressed to a significant extent. The major reason for this great achievement lies in the combined effect of both structure modification and integration of different functional materials. Here, we report a ternary hybrid containing wide band gap CeO₂ nanosheets with CdSQDs and Au nanoparticles, incorporated between this type II heterostructure through simple chemical reduction methods. Structural and morphological characterization of the fabricated samples was carried out by XRD, XPS, and TEM analysis. From a series of optical and photoelectrochemical measurements, it was found that the incorporation of Au nanoparticles into the interfaces of CeO₂ and CdSQDs was the major cause of the enhancement in the photocatalytic activity. Au nanoparticles play a dual character by acting as a mediator and also inject hot electrons through LSPR (light-induced surface plasmon resonance) effects in the ternary hybrid. The photocatalytic activity of the fabricated samples was tested toward H₂ evolution, where the ternary hybrid CeO₂NS-Au-CdSQDs lead the activity sequence with 499 μmol/2 h followed by the binary and neat counterparts. From the Mott-Shottky and linear sweep voltammetry measurements, a heterostructure relay mechanism was predicted where electrons from CdSQDs flow to the surface of CeO₂ via Au. The novelty of this work is that it provides useful information about the synergistic effect among three functional components, integrated in a nanosheet structured system, as the basic requirement for constructing good heterostructures in powdered photocatalytic systems.