Sonochemical method for synthesizing Co_3O_4/graphene nanocomposites for use as counter electrode in dye-sensitized solar Cells

摘要

Co_3O_4/graphene nanocomposites were synthesized via sonochemical method, and its application as a counter electrode (CE) for dye-sensitized solar cell (DSSC) was demonstrated. The prepared Co_3O_4/graphene nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, and UV-Vis absorption spectroscopy. The results of SEM showed that Co_3O_4 nanoparticles deposited on the graphene sheets as spacers to keep the neighboring sheets separated. The Co_3O_4 have diameters ranging from 16 to 43 nm. The influence of the Co_3O_4 content on the photovoltaic performance of dye-sensitized solar cell was investigated. It was found that the performances of Co_3O_4/graphene composites are better than that of graphene-based DSSCs. The Co_3O_4/graphene composite CE with 80 % Co_3O_4 content exhibits the best conversion efficiency (PCE) of 2.1 %.