Investigation of structural, linear, and nonlinear optical properties of nanosized zinc oxide and cadmium oxide particles ingrained in graphitic carbon nitrides

Abstract

The study aims to evaluate the third-order optical nonlinearity caused by laser irradiation in transition metal oxide incorporated into graphitic carbon nitrides. The work describes the synthesis of nano-sized hybrid g-C3N4/ZnO (14%) and g-C3N4/CdO (14%). Nano-sized transition metal oxides: ZnO and CdO, have been prepared by thermally decomposing the organic precursors; Zinc Acetate Dihydrate, Cadmium Acetate Dihydrate, and Urea at 873 K. Graphitic carbon nitrides are synthesized from urea, which also functions as a reducing agent. The synthesized sample’s structural and morphological characterization are investigated using x-ray diffraction (XRD), Fourier transforms infrared (FTIR), UV–vis. spectra, field emission scanning electron microscopy (FESEM), and energy dispersive x-ray spectroscopy (EDX). The grain size of the ZnO and CdO nanoparticles is observed to be ∼21 nm and ∼28 nm, respectively. The absorption in the samples is found to be 250–450 nm and transmit the light in the visible spectrum as observed in UV–vis. spectra. The bandgap values calculated from Tauc’s plot for the hybrid structure of g-C3N4/ZnO and g-C3N4/CdO are found to be 2.97 eV and 2.30 eV.The z-scan method is adopted to evaluate the nonlinear susceptibility (χ3), intensity-dependent absorption coefficient (β), and nonlinear index of refraction (n2) using a pulsed Nd:YAG laser (∼532 nm). The results of the composite of g-C3N4/ZnO and g-C3N4/CdO show good third-order susceptibility and hence are useful for use as an optical limiter.