Nanostructured Platinum Films Deposited by Polyol Reduction of a Platinum Precursor and Their Application as Counter Electrode of Dye-Sensitized Solar Cells

Abstract

Platinum precursors such as H 2 PtCl 6 can be reduced to platinum (Pt) by polyols at temperatures below 200 °C. This method was developed to deposit nanostructured Pt films on various substrates through a solution process. High-quality Pt films with good adhesion to substrate were obtained on substrates like conducting polymer films, indium tin oxide (ITO), and polyimide by dropping a solution of H 2 PtCl 6 in ethylene glycol (EG). Two types of Pt structures, that is, dense and porous Pt structures, were observed for the Pt deposited by EG reduction. The dense Pt structure is the result of Pt growth from the substrate immediately after the reduction. This Pt growth from the substrate can produce a continuous nanostructured Pt film with metallic luster and good adhesion to the substrate. The porous Pt structure is the result of the nucleation of Pt in solution. The Pt nucleation in solution gives rise to Pt particle formation. These Pt particles aggregate and finally precipitate as porous Pt on the dense Pt. The quality of the Pt film was affected by the experimental conditions, such as substrate, concentration, and pH value of H 2 PtCl 6 solution in EG, and temperature during the reduction. Pt deposited by this method could be used as the counter electrode of high-performance dyesensitized solar cells (DSCs). The DSCs exhibited a light-to-electricity conversion efficiency of 8.1%, quite close to that of the DSCs with Pt counter electrode prepared by the conventional pyrolysis. In addition, this low-temperature method enabled the Pt deposition on flexible substrate, which could be used as the flexible counter electrode for DSCs.

Polymer end-group mediated synthesis of well-defined catalytically active platinum nanoparticles

“…Previous research has shown the use of alcohols as active platinum reductants in the presence of polymers. 52,53 FTIR analyses further showed that these weak carbonyl-platinum interactions could be dissociated by acids such as the electrolytes used for ORR since simple rinsing of the PEG-Pt particles in 0.5M H 2 SO 4 caused the polymers to wash off (Fig. 3A, S2).…”

Synthesis of Platinum Catalyst Clusters and Electrochemical Investigation of Stability

“…Similar synthesis procedure as reported by Sun et al was used (16). All substrates were cleaned using the procedure described earlier.…”

Nanofabrication of uniform and stabilizer-free self-assembled platinum monolayers as counter electrodes for dye-sensitized solar cells

“…Under such a thermal treatment, the shapes and the sizes of the nanostructures are difficult to control because of their deformation or aggregation at high temperatures. Although Cho et al 23,24 reported a polyol reduction to prepare Pt CEs for DSSCs at temperatures of 160-180 1C, it is difficult to prepare the thin layer of Pt nanostructures with a uniform morphology and size distribution on TCO at temperatures near 295 K, in particular, to obtain the advantages of excellent electrocatalytic function, large active surface area and effective adhesion to the substrate. As highlighted in Figure 1, in the present work, we demonstrate a feasible strategy for preparing self-assembled Pt monolayers (SAM-Pt) on the surface of TCO in two steps without adding a surfactant or protective agent; thus, the postheating step is avoided.…”