Hydrothermal Synthesis and Micro-Structural, Optical and Luminescence Properties of Core-Shell Hetero Structure CdS/Zn3(PO4)2 Nanocomposite

Abstract

The hydrothermal approach was used to make an inorganic semiconducting CdS/Zn3(PO4)2 nanocomposite at a mild reaction temperature of 100 ºC. The XRD data indicate peaks that correspond to CdS hexagonal structure and Zn3(PO4)2 monoclinic-phase with good crystalline character. Surprisingly, the phase shift from α-phase of Zn3(PO4)2 to γ-phase of Zn3(PO4)2 is observed under hydrothermal conditions due to the coupling of CdS with Zn3(PO4)2, as well as internal structural alterations leading to the formation of CdS/Zn3(PO4)2 nanocomposite. Debye-Scherrer and W-H methods were used to calculate average crystallite size, lattice strain and dislocation density. The average crystal lattice is 15-25 nm in size. The hexagonal spheres aggregated on rectangular flakes, indicating core-shell heterostructure, may be seen on the surface morphology of the prepared composite. Due to the quantum size effect, the absorption peak for the composite is in the visible wavelength. It also has a low optical band gap of 2.42 eV, which makes it useful for photocatalytic and photoelectrochemical applications. FT-IR spectrum shows all the fundamental vibrational modes of CdS/Zn3(PO4)2 nanocomposite. Colour coordinate values and CCT values of the prepared composites indicate that they are used for LED applications and the photoluminescence spectrum reveals a broad, intense luminescence band in the visible region with wavelengths ranging from 510 to 518 nm, in good agreement with the absorption wavelength and the CIE diagram.