Nestor Guijarro Carratala
Néstor Guijarro obtained his PhD in Material Science from the University of Alicante, Spain (May 2013) under the supervision of Prof. Roberto Gómez and Prof. Teresa Lana-Villarreal, experts in the field of (photo)electrochemistry and material synthesis. His PhD thesis focused on the design and optimization of an emerging photovoltaic technology, the so-called Quantum Dot-sensitized solar cells (QDSSCs). To this purpose he undertook a multidisciplinary work that brought about new QD materials with enhanced light harvesting and novel routes to finely engineer the interfacial carrier dynamics at the nanoscale, which all in all, helped redrawing the designing rules of these devices. During this period, he also worked as a visiting scholar in the groups of Prof. Qing Shen and Prof. Taro Toyoda at the University of Electro-Communications (Japan) and in the group of Prof. Saif A. Haque in the Imperial College of London (UK) where he gained hands-on expertise on state-of-the-art pump-probe spectroscopies to interrogate the ultrafast carrier dynamics in these devices.
Before obtaining his PhD, he was awarded with the prestigious Marie Curie fellowship (project COCHALPEC) to develop solution-processable copper-based chalcogenides for photoelectrochemical hydrogen production under the supervision of Prof. Kevin Sivula at the EPFL. Here, he exploited the ease of processing and immense composition/optoelectronics tunability of semiconductor nanocrystals to fabricate photocathodes and test surface modification strategies, uncovering the unique potential of these materials for light-assisted hydrogen production. Simultaneously, he studied the prospects of spinel ferrites, very stable, highly versatile but very rarely explored materials, as photoanodes for oxygen evolution. This studies aimed at unveiling the intrinsic issues that limit their catalytic response and at rationally designing surface and bulk engineering treatments to ameliorate their performance.
Since 2016, upon being awarded with an Ambizione Energy grant from the Swiss National Science Foundation, he holds the position of project leader in Sivula’s group developing new materials for photoelectrochemical water splitting and establishing a unique electrochemical platform to probe the elusive energetic and kinetic information of the photoelectrocatalytic reactions at the electrode-electrolyte interface in-operando.
Photoelectrochemical Water SplittingDeveloping new strategies to harvest the sunlight’s energy has been one of my major objectives since early in my career as a researcher, and particularly photovoltaic and photoelectrochemical energy conversion have been drawing much of my attention. My research interests encompass not only the synthesis of new materials but also the development of new tools that could help us understand and adjust the complex processes that control the energy conversion.
My present research entails the development of a novel electrochemical platform to access energetic and kinetic information of the photoelectrocatalytic reactions occurring at the photoelectrode/electrolyte interface in-operando, a crucial piece of information that remains elusive to date and could reshape the photoelectrochemical-based technology. More specifically, I am probing the electrochemical surface characteristics of the electrode during the hydrogen and oxygen evolution reactions which reveals not only the electrochemical fingerprint of the reaction intermediates, but provides for the first time a direct measurement of the kinetics of the reactions. The main motivation for this line of research is to provide an unambiguous diagnosis of the parameters that constrain and direct the performance of state-of-the-art materials which will guide us in the design of precise surface engineering approaches to enhance the solar energy conversion.