Novel synthesis, DFT and investigation of the optical and electrical properties of carboxymethyl cellulose/thiobarbituric acid/copper oxide [CMC + TBA/CuO]C nanocomposite film

Abstract

A novel synthesis blend of sodium carboxymethyl cellulose (CMC) with thiobarbituric acid (TBA) [CMC + TBA]B has been doped with CuO to study the optical and direct electrical (DC) properties of [CMC + TBA/CuO]C nanocomposite films. Different characterization techniques for [CMC]TF, [TBA]TF, [CMC + TBA]B and [CMC + TBA/CuO]C such as Fourier-transform infrared spectroscopy (FTIR), Ultraviolet–visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and optical properties have been used. SEM showed a good dispersion of copper oxide nanoparticles [CuO]NPs on [CMC + TBA]B film surface. The dielectric constant e(ω), optical conductivity σ(ω) and DC properties increased and demonstrated wave-like performance with increasing [CuO]NPs ratio at hν range of 0.7 eV – 5.0 eV. Copper content [CuO]NPs increases lead to the formation of a wide variety of 3D-semiconductor networks within [CMC + TBA]B film matrix which increase optical conductivity. The optimization was performed using density functional theory (DFT) by DMol3 and Cambridge Serial Total Energy Package (CASTEP). In Experimental section by using Tauc’s equation, the results clearly show that the values of optical energy band gap $$ {E}_g^{Opt} $$ decreases from 2.978 eV for [CMC]TF, 2.725 eV for [TBA]TF, 2.625 eV for [CMC + TBA]B to 2.488 eV for [CMC + TBA/CuO]C. The simulated FTIR, XRD, and optical properties by Gaussian software and CATSTEP are in great agreement with the experimental study. The [CMC + TBA/CuO]C presents a good candidate for optoelectronics and solar cell applications.