Performance evaluation of optimized leaf-shaped two-dimension (2D) potassium doped CuO nanostructures with enhanced structural, optical and electronic properties

Abstract

The present work reports synthesis of pristine and potassium (K) doped cupric oxide (Cu1-xKxO, where x = 0.02, 0.04, 0.06 and 0.08) nanoleaves (CuO-NLs) with preferred growth along [010] plane via co-precipitation synthesis route. The XRD and Raman results exhibited potassium generated defects, oxygen vacancies and strain in CuO lattice due to remarkable difference in the ionic radii, and Pauling electro-negativity of K+ and Cu2+ ions. These defects in the crystal lattice of CuO lead to reduction in crystallite size from 31 nm to 22 nm, without altering the monoclinic structure of CuO. The TEM images revealed the formation of leaf-shaped two-dimension (2D) CuO nanostructures. FTIR results further confirmed the presence of the Cu–O stretching vibrations in doped samples. In the optical properties, diffuse reflectance (DR) and photoluminescence (PL) measurements were performed. DR spectra were used to determine the bandgap and it decreased in the doped samples. A wellspring of emission was observed and the influence of doping concentration on PL properties was systematically studied. Impedance spectroscopy study revealed that the presence of K+ ion boosts the ac conductivity and dielectric constant up-to ~104. Nyquist plot confirms the major contribution of grain boundary to the total capacitance and resistivity of the samples. As-synthesized K doped CuO nanostructures due to enhanced structural, optical and electronic properties hold high potential of applications in various fields.