Solid-state preparation of CuO/ZnO nanocomposites for functional supercapacitor electrodes and photocatalysts with enhanced photocatalytic properties

In this paper, hybrid CuO/ZnO nanocomposites are synthesized by a simple and cost-effective solid-state grinding method for multifunctional applications as supercapacitor electrodes and photocatalysts for the degradation of dye pollutants. In the synthesis process, ZnCO3-SLS used as a reactant that not only provides Zn source but also serves as a template to induce the nanoparticles to arrange orderly. The resultant CuO/ZnO (ZnCO3-SLS, 1.00 g) nanocomposites exhibit a maximum degradation efficiency of 91.5% for Rhodamine B and 74.3% for Congo Red under visible light irradiation for 240 min, respectively. Besides, it also demonstrates high specific capacitance of 579.5 F g(-1) and excellent cyclic performance with nearly 83.0% capacity retention after 2000 cycles at a current density of 5 A g(-1), seemed to be superior to other nanocomposites. The excellent electrochemical performance can be attributed to a rational combination of two electrochemical active materials. The hybrid nanocomposites design opens up new opportunities to use in wastewater treatment and energy storage applications. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.