Efficient Nickel Sulfide and Graphene Counter Electrodes Decorated with Silver Nanoparticles and Application in Dye-Sensitized Solar Cells.

Gentian Yue,Guang Yang,Fumin Li,Weifeng Zhang

doi:10.1186/s11671-016-1456-z

Abstract

We reported a facile two-step electrochemical-chemical approach for in situ growth of nickel sulfide and graphene counter electrode (CE) decorated with silver nanoparticles (signed NiS/Gr-Ag) and served in dye-sensitized solar cells (DSSCs). Under optimum conditions, the DSSC achieved a remarkable power conversion efficiency of 8.36 % assembled with the NiS/Gr-Ag CE, much higher than that based on the Pt CE (7.76 %). The surface morphology of NiS/Gr-Ag CE exhibited a smooth surface with cross-growth of NiS, graphene, and Ag nanoparticles, which was beneficial to the fast mass transport of electrolytes; increased the contact area of electrolytes and active materials; and enabled to speed up the reduction of triiodide to iodide. The research on the electrochemical properties also showed that the NiS/Gr-Ag CE possessed lower charge transfer resistance and more excellent electrocatalytic activity in iodide/triiodide electrolyte compared to the Pt electrode.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-016-1456-z) contains supplementary material, which is available to authorized users.

Highlights

With photovoltaic technology being realized as a suitable renewable power for the fulfillment of increasing world energy consumption, dye-sensitized solar cells (DSSCs) have attracted a great deal of attention because of their potential as next-generation photovoltaic devices [1,2,3]
It is clear that the nickel sulfide (NiS)/Gr-Ag counter electrode (CE) possessed a uniform and smooth surface with graphene, NiS, and Ag nanoparticles distributed on the fluorine-doped tin oxide (FTO)* surface, which featured a nanowall network-like shape
We attributed the formation of the NiS/Gr-Ag nanowall to the high surface energy of Ag nanoparticles which made the Ag nanoparticles clustered and coated on the NiS/Gr surface

Summary

Introduction

With photovoltaic technology being realized as a suitable renewable power for the fulfillment of increasing world energy consumption, dye-sensitized solar cells (DSSCs) have attracted a great deal of attention because of their potential as next-generation photovoltaic devices [1,2,3]. The NiS/Gr-Ag CE was provided with the least overpotential and most excellent electrochemical catalytic ability for an electron transferring in I−/I3− redox species among the six CEs. Figure 5a depicted the cyclic voltammograms of the various electrodes under the I−/I3− electrolyte system at a scan rate of 50 mV s−1.

Results

Conclusion