Diseño de interfases funcionales: Estudio de procesos de transferencia electrónica a través de monocapas moleculares autoensambladas sobre oro

El proyecto aborda el estudio de la transferencia electrónica sobre superficies de oro modificadas con monocapas autoensambladas (SAMs) puras o mixtas, es decir, constituidas por uno o varios componentes moleculares. Este estudio contribuye al desarrollo de conceptos fundamentales en áreas de investigación relacionados con la Electroquímica Interfacial, Bioelectroquímica, Electrocatálisis, Ciencia de Superficies y Nanociencia y Nanotecnología.1-7 El interés fundamental de estos sistemas radica en las expectativas que suscita el diseño de interfaces donde la composición y distribución superficial de sus componentes puede ser controlada a escala nanométrica a partir del concepto de ensamblaje molecular. Además, la organización estructural de las SAMs también determina las interacciones con otros materiales, y la forma en que se inmovilizan. La influencia de todos estos aspectos en la transferencia electrónica de proteínas redox como la Myoglobina es básica para explicar tanto su función como la dinámica de diferentes procesos biológicos, así como para el diseño racional de sensores y biosensores electroquímicos.3-7. Con este trabajo se logra el control a nivel molecular de la organización de SAMs puras y mixtas a nivel molecular, en particular en la funcionalización superficial de sustratos de Au con alcanotioles ω-sustituidos (ej. grupos terminales –COOH, -CH3, etc.). Se estudia detalladamente con técnicas de caracterización electroquímicas (VC, EIS, etc.) y espectroscópicas (RR, IRRAS) las interacciones electrostáticas e hidrofóbicas de la Myoglobina con las interfaces funcionalizadas diseñadas, y en consecuencia su efecto sobre la transferencia electrónica y capacidad electrocatalítica del grupo redox

Experimental and Theoretical Advances on Single Atom and Atomic Cluster-Decorated Low-Dimensional Platforms towards Superior Electrocatalysts

The fundamental relationship between structure and properties, which is called “structure-property”, plays a vital role in the rational designing of high-performance catalysts for diverse electrocatalytic applications. Low-dimensional (LD) nanomaterials, including 0D, 1D, 2D materials, combined with low-nuclearity metal atoms, ranging from single atoms to subnanometer clusters, are currently emerging as rising star nanoarchitectures for heterogeneous catalysis due to their well-defined active sites and unbeatable metal utilization efficiencies. In this work, a comprehensive experimental and theoretical review is provided on the recent development of single atom and atomic cluster-decorated LD platforms towards some typical clean energy reactions, such as water-splitting, nitrogen fixation, and carbon dioxide reduction reactions. The upmost attractive structural properties, advanced characterization techniques, and theoretical principles of these low-nuclearity electrocatalysts as well as their applications in key electrochemical energy devices are also elegantly discussed

Boosting the electrochemical oxygen reduction activity of hemoglobin on fructose@graphene-oxide nanoplatforms

A metal-free oxygen reduction reaction (ORR) electrocatalyst with outstanding performance was obtained through an easy and one-pot synthesis of hemoglobin functionalized fructose@graphene-oxide (GO) nanocomposites. The active pyridinic nitrogen sites of the highly unfolded proteins together with the excellent electronic properties of GO appears to be the main factors causing the improved electrocatalytic activity

Facile synthesis of C60-nano materials and their application in High-Performance Water Splitting Electrocatalysis

Here, we report the synthesis and characterization of crystalline C60 nanomaterials and their applications as bifunctional water splitting catalysts. The shapes of the resulting materials were tuned via a solvent engineering approach to form rhombic-shaped nanosheets and nanotubes with hexagonal close packed-crystal structures. The as-synthesized materials exhibited suitable properties as bifunctional catalysts for HER and ORR reactions surpassing by far the electrocatalytic activity of commercially available amorphous C60. The C60 nanotubes displayed the most efficient catalytic performance with a small onset potential of −0.13 V vs. RHE and ultrahigh electrochemical stability properties towards the generation of molecular hydrogen. Additionally, the rotating-disk electrode measurements revealed that the oxygen reduction mechanism at the nanotube electrochemical surfaces followed an effective four-electron pathway. The improved catalytic activity was attributed to the enhanced local electric fields at the high curvature surfaces

Citrate-Stabilized Gold Nanoparticles as High-Performance Electrocatalysts: The Role of Size in the Electroreduction of Oxygen

Fuel cells stand out as among the most promising alternatives for non-sustainable fossil fuel based economy. Efficient electrocatalysts for the oxygen reduction reaction (ORR) are required for the mass application of fuel cells. Citrate-stabilized gold nanoparticles (AuNPs) are proposed as potentialdependent electrocatalysts for the ORR. AuNPs were synthesized by a green, reproducible, and easy scale-up method. After exhaustive characterization, the electrocatalytic activity of the resulting AuNPs was investigated in alkaline media. Static and dynamic electrochemical studies showed a core-size dependent tendency both for their potentials and intensities. For the first time ever, the hysteresis effect in the ORR profile over Au nanoelectrocatalysts is reported herein. In addition, the electrocatalytic efficiency was comparable to those obtained for Au clusters, suggesting the benefits of the citrate stabilizing agent on the electrocatalyst performance of nanomaterials based on noble metals for ORR. These results pave the way for the design of non-coated AuNPs as strong candidates for ORR