Fabrication of large Pt nanoparticles-decorated rGO counter electrode for highly efficient DSSCs

Abstract This study describes the radiolytic fabrication of large Pt nanoparticles (NPs)-decorated reduced graphene oxide (L-Pt/rGO) and its use as a counter electrode (CE) in dye-sensitized solar cells (DSSCs). A homogenous aqueous solution of GO in 10 wt% isopropyl alcohol (IPA) aqueous solution containing Pt precursor was irradiated with γ-ray at room temperature to prepare the L-Pt/rGO. The analytic results from TEM, EDX, XPS, and Raman revealed that the rGO decorated with 100 nm Pt NPs was successfully formed by the γ-ray irradiation-induced reduction of both the GO and Pt precursor in aqueous IPA solution. Based on the results of the DSSCs performance test, the energy conversion efficiency of the DSSCs with the L-Pt/rGO-based CE outperformed that with the rGO-based one due to the lower sheet resistance, and even was comparable to that of the Pt-based CE. This L-Pt/rGO fabricated by a simple, room temperature and scalable radiolytic method can be used as a promising CE material for low-cost and high-performance DSSCs.