Structural, photoluminescence and electrochemical properties of rGO/La2O3 nanocomposites for supercapacitor electrode application

This study presents the synthesis of a series of rGO(reduced graphene oxide)/La2O3(lanthanum oxide) nanocomposites using the facile chemical technique for improved energy storage in supercapacitors. X-ray diffraction (XRD) and Energy Dispersive X-Ray Analysis (EDX) characterization confirmed the presence of La2O3 nanoparticles. The crystallite size (D) and particle size of rGO/La2O3 nanocomposites varied from 20.21 to 28.4 nm and 400 to 550 nm respectively from XRD and SEM image analysis. The optical band gap decreased from 5.1 to 4.2 eV with increasing rGO content. Microstrain of rGO/La2O3 nanocomposites increased with increasing of rGO content. The structural quality factor of the carbon network, I-D/I-G decreased from 1.36 to 1.31 indicating decreasing in functional groups from the rGO surface. The maximum specific capacitance (Csp) is observed up to 708.33 F/g at 5 mV/s scan rate and a decrease in internal resistance by varying the rGO content from 10 to 30 wt%. The enhanced Csp values and low internal resistance can rGO/La2O3 nanocomposites an effective supercapacitor material.