Preparation and Characterization of Thermoelectric PEDOT/Te Nanorod Array Composite Films

In this study, we prepared Te nanorod arrays via a galvanic displacement reaction (GDR) on a Si wafer, and their composite with poly(3,4-ethylenedioxythiophene) (PEDOT) were successfully synthesized by electrochemical polymerization with lithium perchlorate (LiClO4) as a counter ion. The thermoelectric performance of the composite film was optimized by adjusting the polymerization time. As a result, a maximum power factor (PF) of 235 µW/mK2 was obtained from a PEDOT/Te composite film electrochemically polymerized for 15 s at room temperature, which was 11.7 times higher than that of the PEDOT film, corresponding to a Seebeck coefficient (S) of 290 µV/K and electrical conductivity (σ) of 28 S/cm. This outstanding PF was due to the enhanced interface interaction and carrier energy filtering effect at the interfacial potential barrier between the PEDOT and Te nanorods. This study demonstrates that the combination of an inorganic Te nanorod array with electrodeposited PEDOT is a promising strategy for developing high-performance thermoelectric materials.

Synthesis of Pt-Ni/CNT Cathodic Catalyst and its Application in a PEM fuel Cell

This work reports the synthesis, characterization, and catalytic activity of Pt-Ni/CNT with a low platinum load to use as cathode electrocatalyst in PEMFC (proton-exchange membrane fuel cells). The synthesis of nickel particles on the carbon nanotubes surface was carried out by chemical reduction of a Ni(ethylenediamine) complex; after that, the galvanic displacement reaction was performed to platinum deposition onto Ni/CNT. The Pt-Ni/CNT was deposited by spray technique on a gas diffuser layer (GDL) and subsequently subjected to several potential cycles to promote Ni atoms migration. Finally, its catalytic activity was evaluated in a fuel cell. Resumen. En este trabajo, se reporta la síntesis, caracterización y evaluación catalítica del electrocatalizador Pt-Ni/CNT con bajo contenido de platino, empleado como electrocatalizador catódico en una celda de combustible tipo PEMFC (Celda de combustible de membrana de intercambio protónico). La síntesis de las partículas de níquel sobre la superficie de los nanotubos de carbono se llevó a cabo mediante la reducción química del complejo de Ni(etilendiamina) y posteriormente, se depositó platino sobre el material Ni/CNT mediante la reacción de desplazamiento galvánico. Se depositó una película de Pt-Ni/CNT sobre un difusor de gas mediante la técnica de esprayado y posteriormente fue sometido a diversos ciclos de potencial para promover la migración de los átomos de níquel y evaluar su actividad catalítica en una celda de combustible.