Enhanced Electrochemical Catalytic Efficiencies of Electrochemically Deposited Platinum Nanocubes as a Counter Electrode for Dye-Sensitized Solar Cells

Yu-Hsuan Wei,Ming-Chi Tsai,Fan-Gang Tseng,Hsuan-Chung Wu,Chen-Chi M Ma,Chien-Kuo Hsieh,Chuen-Horng Tsai

doi:10.1186/s11671-015-1177-8

Abstract

Platinum nanocubes (PtNCs) were deposited onto a fluorine-doped tin oxide glass by electrochemical deposition (ECD) method and utilized as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). In this study, we controlled the growth of the crystalline plane to synthesize the single-crystal PtNCs at room temperature. The morphologies and crystalline nanostructure of the ECD PtNCs were examined by field emission scanning electron microscopy and high-resolution transmission electron microscopy. The surface roughness of the ECD PtNCs was examined by atomic force microscopy. The electrochemical properties of the ECD PtNCs were analyzed by cyclic voltammetry, Tafel polarization, and electrochemical impedance spectra. The Pt loading was examined by inductively coupled plasma mass spectrometry. The DSSCs were assembled via an N719 dye-sensitized titanium dioxide working electrode, an iodine-based electrolyte, and a CE. The photoelectric conversion efficiency (PCE) of the DSSCs with the ECD PtNC CE was examined under the illumination of AM 1.5 (100 mWcm−2). The PtNCs in this study presented a single-crystal nanostructure that can raise the electron mobility to let up the charge-transfer impedance and promote the charge-transfer rate. In this work, the electrocatalytic mass activity (MA) of the Pt film and PtNCs was 1.508 and 4.088 mAmg−1, respectively, and the MA of PtNCs was 2.71 times than that of the Pt film. The DSSCs with the pulse-ECD PtNC CE showed a PCE of 6.48 %, which is higher than the cell using the conventional Pt film CE (a PCE of 6.18 %). In contrast to the conventional Pt film CE which is fabricated by electron beam evaporation method, our pulse-ECD PtNCs maximized the Pt catalytic properties as a CE in DSSCs. The results demonstrated that the PtNCs played a good catalyst for iodide/triiodide redox couple reactions in the DSSCs and provided a potential strategy for electrochemical catalytic applications.

Highlights

In the recent years, Grätzel and many scientists have been attracted to study potential candidates of dye-sensitized solar cells (DSSCs) for next-generation solar cells [1,2,3]
From the atomic force microscopy (AFM) results, both Ra and Rq of the Platinum nanocubes (PtNCs) were higher than those of the Pt film, and this phenomenon coincided with the field emission scanning electron microscopy (FESEM) images
In this work, the single-crystal nanostructure of PtNCs was successfully developed at room temperature by the pulse-mode electrochemical deposition (ECD) technique to be deposited onto the Characterization of the DSSCs The photovoltaic characteristics of the DSSCs were executed by measuring the photocurrent–photovoltage (J–V) characteristic curve under the simulated solar illumination

Summary

Introduction

Grätzel and many scientists have been attracted to study potential candidates of dye-sensitized solar cells (DSSCs) for next-generation solar cells [1,2,3]. The most common nanomaterials applied to the CE for DSSC investigations were Pt [7, 8], carbon nanotubes [9, 10], graphene [11, 12], graphene oxide [13], molybdenum sulfide [14,15,16], etc Among those electrocatalytic materials, Pt exhibits the best electrocatalytic performance, which was widely used in fuel cells, biosensors, and chemical sensor development of the advanced technologies for kinds of the environmental, renewable energy, and industrial process [17,18,19,20]. The challenge to synthesize the unique morphology of single-crystal Pt nanomaterial still remains [27,28,29]

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Results

Conclusion