▎ 摘　　要

Platinum nanoparticles (PtNPs)-loaded holey reduced graphene oxide framework (Pt/HGF) has been synthesized as freestanding counter electrodes (CEs) of dye sensitized solar cells (DSSCs) and methanol oxidation catalysts. PtNPs (similar to 2.5 nm) are uniformly incorporated into holey reduced graphene oxide framework by a solvothermal treatment. Pt/HGF possesses high specific surface area (340.65 m(2) g(-1)). Its charge transfer resistance (R-CT) at the I-/I-3(-) electrolyte/CE interface reaches 1.61 Omega cm(2), lower than that of pure Pt (2.99 Omega cm(2)) and PtNPs loaded non-hole reduced graphene oxide (Pt/G, 2.37 Omega cm(2)), and its RCT at the methanol electrolyte/electrode interface (0.75 Omega cm(2)) is much lower than that of Pt/G (3.14 Omega cm(2)), showing good electrocatalytic activity for I-/I-3(-) redox reaction and methanol oxidation reaction (MOR). The assembled Pt/HGF-DSSC achieves a photoelectric conversion efficiency of 5.55% and a short-circuit current density (J(sc)) of 12.27 mA cm(-2), better than those of Pt-DSSC (5.19%, 10.50 mA cm(-2)) and Pt/G-DSSC (5.12%, 11.12 mA cm(-2)). In methanol oxidation test, Pt/HGF delivers better electrocatalytic activity and stability than Pt/G. Thus, high electrocatalytic activity and efficient electron/ion transport are achieved by Pt/HGF due to the synergistic effect of well dispersed PtNPs, hierarchical holey structure, and framework, and it may serve as an alternative of pure Pt for DSSC-CEs and MOR catalysts. (C) 2017 Elsevier Ltd. All rights reserved.