Tri-iodide Reduction Activity of Shape- and Composition-Controlled PtFe Nanostructures as Counter Electrodes in Dye-Sensitized Solar Cells

详细信息    查看全文

• 作者：Pei-Jen Chang ; Kum-Yi Cheng ; Shang-Wei Chou ; Jing-Jong Shyue ; Ya-Yun Yang ; Chang-Yu Hung ; Ching-Yen Lin ; Hui-Lung Chen ; Hung-Lung Chou ; Pi-Tai Chou
• 刊名：Chemistry of Materials
• 出版年：2016
• 出版时间：April 12, 2016
• 年：2016
• 卷：28
• 期：7
• 页码：2110-2119
• 全文大小：709K
• 年卷期：0
• ISSN：1520-5002

文摘

PtFe alloy nanostructures enclosed by differently oriented facets, including polyhedrons, concave cubes, and nanocubes, were synthesized through the fine adjustment of specific surfactant–crystal facet bindings. PtFe nanostructures with various alloy compositions were then employed as the counter electrodes (CEs) for the redox reaction of iodide/tri-iodide (I^–/I₃^–) in dye-sensitized solar cells. Devices with the Pt₉Fe₁ polyhedrons and Pt₉Fe₁ concave cubes produced better photovoltaic conversion efficiency (PCE) of 8.01% and 7.63% in comparison to the PCE of 7.24% achieved with Pt CE. The superiority is attributed to the rapid charge transfer, higher limit current, and better electronic conductivity and catalytic activity with respect to the Pt CEs. The photovoltaic and electrochemical results indicated the shape- and composition-dependent activity in the I^–/I₃^– redox reaction, which obeys the sequence of polyhedrons > concave cubes > nanocubes and Pt₉Fe₁ nanostructures > Pt₇Fe₃ nanostructures. Further theoretical work indicated that the I₃^– reduction activity of the nanosurfaces was in the order of Pt₉Fe₁(111) > Pt(111) > Pt₉Fe₁(100). The combination of experimental and theoretical work thus clearly demonstrates the shape- and composition-dependence of PtFe nanostructures in terms of the I₃^– reduction activity.