Kim, Young-Gon Akbar, Zico Alaia Kim, Dong Young Jo, Seong Mu Jang, Sung-Yeon 2024-01-20T13:00:56Z 2024-01-20T13:00:56Z 2021-09-01 2013-03 1944-8244 https://pubs.kist.re.kr/handle/201004/128318 Aqueous dispersible nanohybrids (NHBs) of graphene nanosheets (GNSs) and Pt nanoparticles (Pt-NPs) were synthesized through the one-pot reduction of their precursors using an environmentally benign chemical, vitamin C. The concurrent reduction of the precursors, which includes graphene oxide (GO) to GNS and H2PtCl6 to Pt-0, was facile and efficient to yield GNS/Pt-NHBs in which face-centered cubic (fcc) crystalline Pt-NPs with average diameters of similar to 5 nm were robustly attached on the surface of the GNSs. The conversion yield during Pt reduction was fairly high (similar to 90%) and the Pt content within the NHBs was easily controllable. The resulting stable aqueous colloidal dispersion of GNS/Pt-NHBs was successfully fabricated as thin films without using any binder by the electro-spray method at room temperature, and the fabricated samples were used as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The electrocatalytic activity of the NHBs for I-/I-3(-) redox couples in conventional DSSCs was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analysis. Doping of GNSs with small amounts of Pt-NPs (<10 wt %) could dramatically enhance the redox kinetics. The enhanced electrocatalytic activity of the GNS/Pt-NHBs was reflected in the performance of the DSSCs. The power conversion efficiency of optimized DSSCs using the NHB-CEs was 8.91% (V-OC: 830 mV, J(SC): 15.56 mAcm(-2), and FF: 69%), which is comparable to that of devices using the state-of-the-art Pt-based CEs (8.85%). English American Chemical Society Aqueous Dispersible Graphene/Pt Nanohybrids by Green Chemistry: Application as Cathodes for Dye-Sensitized Solar Cells Article 10.1021/am302928x 1 ACS Applied Materials & Interfaces, v.5, no.6, pp.2053 - 2061 ACS Applied Materials & Interfaces 5 6 2053 2061 N scie scopus 000317031900026 2-s2.0-84875727248 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article COUNTER-ELECTRODE ELECTROCATALYTIC ACTIVITY FUNCTIONALIZED GRAPHENE PLATINUM NANOPARTICLES THIN-FILMS VITAMIN-C REDUCTION TRANSPARENT PERFORMANCE FABRICATION graphene nanosheet platinum dye-sensitized solar cell counter electrode electrocatalytic activity