Robust counter electrodes from nanoporous NiM (M=Pt, Pd) alloys for dye-sensitized solar cells

Alloy Nanostructured Catalysts for Cathodic Reactions in Energy Conversion and Fuel Generation

“…Moreover, too much Pd content in the PtPd NP CEs leads to a decrease of PCE and J sc , which is located at the bottom of the volcano-shaped plot. In comparison, the volcano-shaped plot in terms of PCE and J sc values of Pt 1 Pd 1– x NP CEs are different from the case of a previous report based on CEs of the Pt-based alloy. − We consider that Pd metal also acts as a catalyst toward redox reactions, − and thus, Pd metal may play a role with multiple functions rather than just assisting electron transfer in the Pt-based alloy CEs. For a further in-depth understanding, the catalytic activity of I 3 – reduction over the (111) surface of the PtPd alloy was investigated by calculated E abs , to specify the diffusion behavior of I – /I 3 – pairs toward different Pt alloy surfaces. ,, The result predicted that Pt 5 Pd 5 (111) surfaces have the lowest E abs and, thereby, fast diffusion of I – /I 3 – pairs on Pt 5 Pd 5 (111) surfaces.…”

“…Recently, the development of efficient and economical catalysts superior to the traditionally carbon-supported Pt (Pt/C) catalyst thus becomes emergent. Many studies have pointed out that Pt-based alloy nanocatalysts, intermixing two or more 3d transition metals, could attain higher ORR activity. − On the one hand, the relationship between ORR activity and chemical composition has been addressed from the viewpoint of electronic states of Pt-based alloy nanocatalysts. − On the other hand, different Pt-based alloy nanostructured catalysts have been reported to influence their catalytic activities per se as a result of the specific crystallographic planes. − Recently, the tri-iodide reduction reaction (IRR) activity of the counter electrodes (CEs) is considered to be one of the key components for improving the DSSC efficiency. − The catalytic activity of various CE materials has been studied to promote the performance of DSSCs in terms of increasing the photon conversion efficiency (PCE) and reducing the costs, making them more competitive among the various photovoltaic devices. − The Pt-based alloys incorporating a suitable amount and composition of transition metals are able to facilitate the electron transfer between CEs and I – /I 3 – redox pairs. − Furthermore, many researchers have studied the catalytic mechanism of IRR on the Pt-based alloy nanostructures and found the superior IRR activity on the shapes with rich {111} facets. ,, As concluded in previous articles, the shapes and compositions of Pt-based alloy CEs all play important roles in the catalytic activity for IRR in the DSSC devices.…”

Influences of sintering temperature on low-cost carbon paste based counter electrodes for dye-sensitized solar cells

“…19) Since the major concern in this study is to investigate the influence of sintering on the catalytic activities of the CP CE. 20) Hence, the Warburg impedance element has been omitted from the model without influence on the fitted results of impedance parameters. 12) The internal resistance is mainly composed of the series resistance (R 0 ) and the charge transfer resistance (R ct ).…”

“…5(b). 20) The electrons will suffer a resistance when transporting from CE to electrolyte due to the difference between redox species potential of iodide= triiodide (∼4.90 eV) 29) and Φ of CP CE. Generally speaking, the large work function difference between two individual materials increase the contact resistance.…”