Dielectric and impedance studies of binary ZnO–CuO nanocomposites for hydroelectric cell application

Abstract

Nanocomposites of xZnO-(1-x)CuO (x = 0.39, 0.69, 0.85) were synthesized using conventional solid state reaction method. The structural, dielectric and impedance properties of ZnO–CuO nanocomposites have been comprehensively studied. The X-ray diffraction studies show that the crystallite size decreases from 47 nm to 35 nm from 0.85ZnO-0.15CuO to 0.39ZnO-0.61CuO along with lowering of lattice parameter of ZnO–CuO on account of improved crystallinity. The UV–Vis spectroscopy display increase in bandgap with increasing CuO content in the nanocomposites. The dielectric constant in ZnO–CuO nanocomposites is found to improve strongly with CuO content in ZnO–CuO nanocomposites and apprise existence of non-Debye relaxation process. The dielectric loss decreases from 10 to nearly unit value due to increased crystallinity. The impedance spectroscopy analysis indicated the dielectric relaxation to be of poly-dispersive non-Debye type with dominant grain boundary contribution in the ZnO–CuO nanocomposite. The hydroelectric cells of ZnO–CuO nanocomposites exhibited enhanced performance with CuO content on account of improved ionic diffusion. The 0.69ZnO-0,31CuO nanocomposites displayed a constant current of 0.46 mA sustained for up to 3 h. These results make ZnO–CuO nanocomposites suitable for microelectronic and hydroelectric cell applications.