In dye-sensitized solar cell (DSSC) alloys of Pt with other metals or replacement of it with Pt-free alloys can be used to reduce the fabrication cost. Herein, we present the formation of Pt-Ni alloy/reduced graphene oxide (Pt-Ni/RGO) counter electrode (CE) by a simple and environmental-friendly electrochemical deposition method for fabrication of DSSC. First, RGO/FTO CE was prepared through electrophoretic deposition (EPD) method and then reduced electrochemically. Then, Pt-Ni alloy was loaded on CE by cyclic voltammetry (CV) strategy. The morphology of the Pt-Ni/RGO film was characterized by field emission scanning electron microscopy (FESEM) analysis. Pt-Ni nanoparticles were uniformly dispersed on the surface of RGO after electrodeposition. The Pt-Ni/RGO CE showed remarkably enhanced electrocatalytic activities toward triiodide (I3−) reduction reaction in comparable to RGO CE. CV and electrochemical impedance spectroscopy (EIS) confirmed that the Pt-Ni/RGO CE has superior electrocatalytic activity than that of RGO and Pt-Ni CEs. The enhanced electrocatalytic activities can be in association with the synergistic effect of transition metals. As a result, an efficiency of 6.14% with Jsc = 14.08 mA cm−2, Voc = 749 mV, and FF = 0.58 was achieved for DSSC assembled with the Pt-Ni/RGO CE under AM 1.5 illumination of 100 mW cm−2. Thus, the fabricated Pt-Ni/RGO CE could be used as a promising material for a low-cost CE for DSSC.
