Lanthanum sulfide/graphene oxide composite thin films and their supercapacitor application

In this study, graphene oxide, lanthanum sulfide and their composite thin films are prepared using simple and inexpensive chemical methods and their supercapacitive performance is evaluated. The X-ray diffraction study shows the formation of mixed-phase lanthanum sulfide with monoclinic alpha-LaS2 and tetragonal La5S7. Field emission scanning electron microscopy images show porous surface morphology of lanthanum sulfide and composite thin films. The supercapacitive performance of composite film tested in 1 M Na2SO4 electrolyte shows highest specific capacitance of 312 F g(-1) at a 5 mV s(-1) scan rate.