The stabilization of NiCo2O4 nanobelts used for catalyzing triiodides in dye-sensitized solar cells by the presence of RGO sheets

In this report, spinel NiCo2O4 nanobelts anchored on reduced graphene oxide (NiCo2O4@RGO) have been synthesized by a hydrothermal reduction process and used as counter electrode (CE) in dye-sensitized solar cells (DSSC). Without RGO, the NiCo2O4 nanobelts tend to aggregate and form sarciniform patterns. By introducing RGO, the NiCo2O4 nanobelts are dispersed on graphene sheets uniformly. The DSSC based on NiCo2O4 nanobelts CE achieves power conversion efficiency (PCE) of 5.20% and a higher PCE (6.17%) on NiCo2O4@RGO nanocomposite, which was comparable to the Pt CE (6.07%). The cyclic voltammetry tests (CV) analysis indicates that the NiCo2O4@RGO CE gives a more stable catalytic activity for triiodide reduction than NiCo2O4 CE does. Due to the existence of RGO, the composite possesses both higher efficiency and stability. (C) 2015 Elsevier B.V. All rights reserved.