Synthesis and characterization studies of facile CuO:La2O3 nanomaterial and its role as electrode for overall energy storage and energy generation applications

The current study implements an environmental-friendly and sustainable methodology to fabricate CuO:La2O3-based electrode by using phyto-aqueous extract derived from the Amaranthus viridis plant leaves. CuO:La2O3 was synthesized in several concentrations ranging from 2.5 to 10%. The synthesized nanoparticles revealed varied morphology for different concentrations with a varying crystalline size in the range of 18.2-43.44 nm. The lowest optical band gap energy of 3.25 eV was observed for 7.5% doped concentration. Taking advantage of its unique morphology and lower crystalline size, 7.5% CuO:La2O3 was specifically selected to be utilized as an electrode material for subsequent investigations involving supercapacitor and water splitting studies. The supercapacitor behavior was studied using cyclic voltammetry (CV) and galvanostatic charge discharge (GCD) techniques. The specific capacitance value of 879.6 F/g was obtained for the fabricated electrode. The water splitting studies revealed the better potential of fabricated electrocatalyst for oxygen evolution reaction with an overpotential value of 351 mV as compared to that of hydrogen evolution reaction where the overpotential value of 182 mV was observed. Moreover, the fabricated electrocatalyst showed excellent cyclic stability for more than 2000 cycles and up to 20 h. Nevertheless, comprehensive findings displayed CuO:La2O3 as an efficient energy storage material as well as promising catalytic material for the water splitting studies.

Automated summary

This study fabricates a CuO:La2O3-based electrode using a sustainable and environmentally friendly method involving phyto-aqueous extract derived from Amaranthus viridis plant leaves. The synthesized nanoparticles exhibit varying morphology and crystalline size, with the lowest optical band gap energy observed for a 7.5% doped concentration. The fabricated electrode shows a specific capacitance value of 879.6 F/g in supercapacitor studies, and demonstrates excellent cyclic stability for over 2000 cycles and up to 20 hours in water splitting studies. Overall, CuO:La2O3 is identified as an efficient energy storage material and a promising catalytic material for water splitting studies.