Dyovani Coelho

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d.coelho@fz-juelich.de




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The main catalysts used for overall water splitting in alkaline water electrolyzer are based on Ni for hydrogen evolution reaction (HER) and Ni-Co alloys for oxygen evolution reaction (OER); however, they show high overpotentials to these reactions. One promising alternative is the use of catalysts based on non-precious metals such as Ni, Co, and Fe phosphides to overall water splitting.

My goal is the electrodeposition of metal phosphides (MeP), based on Ni, Co, and Fe or their combinations and the evaluation of the activity/stability relationship of the catalysts to both reactions, HER and OER. The catalyst will be electrodeposited on Ni, stainless steel grade 304 into an electrolyte containing the corresponding CoSO4, NiSO4, FeSO4, Na2PO2, and H3PO4 under a galvanostatic regime. The electrodeposition will be done using an electrochemical scanning flow cell (SFC), aiming at high-throughput electrochemistry, changing the concentrations of the precursors into the electrolyte at each deposition cell spot by autonomous testing procedure. I will investigate the activity/stability relationship using a SFC online with Inductive Coupled Plasma Mass Spectrometry (SFC-ICP-MS) in alkaline and neutral solutions, which allows the study of the catalyst activity and the detection of dissolution events related or not to applied potentials and electrolyte composition

It is expected to estimate the viability of catalysts based on MeP to overall water splitting and opens up a simple and cost-efficient method to produce new-generation catalysts to HER and OER.

 


09.2022-Current Postdoctoral fellow in Forschungszentrum Jülich, Helmholtz-Institute Erlangen Nüremberg für Erneuerbare Energie, Germany, supervised by Dr. Serhiy Cherevko. Reserach topic: “Evaluation of the activity-stability relationship and dynamic equilibrium of the metallic phosphides based on Co, Ni, and Fe to overall water splitting”.
11.2021-08.2022 Postdoctoral fellow at the Federal University of Sao Carlos, Brazil, supervised by Profa. Dra. Lucia Mascaro Sales. Research topic: “Electrodeposition of transition metal sulfides and phosphides on 3D printed electrodes to water splitting”.
2019-2021 Postdoctoral fellow at the Federal University of Sao Carlos, Brazil, supervised by Profa. Dra. Lucia Mascaro Sales. Research topic: “Use of oxygen evolution co-catalysts based on Ni, Fe, or Co as a protective layer on WO3/BiVO4 photoanodes to water photo-electrooxidation.”.
2016-2018 Postdoctoral fellow at the Federal University of Sao Carlos, Brazil, supervised by Prof. Dr. Ernesto Chaves Pereira de Souza. Research topic: “Use of nanoporous Al2O3 membrane platforms to obtain CH3NH3PbI3 perovskite structures”.
2015-2016 Postdoctoral fellow at the Federal University of Sao Carlos, Brazil, supervised by Profa. Dra. Lucia Mascaro Sales. Research topic: “Synthesis and characterization of bismuth vanadate to water splitting”.
2011-2015 Ph.D. in chemistry, Institute of Chemistry of Sao Carlos / University of Sao Paulo, Brazil. Supervised by Prof. Dr. Sergio Antonio Spinola Machado. Thesis: “Use of underpotential deposition in the doping of electrodeposited selenium semiconductive films”.
2009-2011 Msc. in chemistry, Institute of Chemistry of Sao Carlos / University of Sao Paulo, Brazil. Supervised by Prof. Dr. Sergio Antonio Spinola Machado. Dissertation: “Electrochemical characterization of a mixed self-assembled monolayer composed of 3-mercaptopropionic and 11-mercaptoundecanoic acids”.
2004-2008 Bsc in chemistry, Ponta Grossa State University, Brazil. Completion of Coursework: “Synthesis of compounds based on silver nanoparticle and polyaniline by layer-by-layer and electropolymerization”.


2019 Honorable mention for the study "Decreasing of the charge recombination in devices for water splitting using the WO3/BiVO4 heterostructure" by João Pedro G. R. Santos, Dyovani Coelho, and Lucia H. Mascaro at XXVI Congress of Scientific Initiation and XI Congress of Initiation in Technological Development and Innovation of the Federal University of Sao Carlos.
2018 Honorable mention for the study "Background current separation of fast-scan cyclic voltammetry by finite element simulation" by Gabriel Wosiak, Dyovani Coelho, Evaldo B. Carneiro-Neto, Ernesto C. Pereira, and Mauro C. Lopes at 1st Biennial Meeting of the Brazilian Society of Electrochemistry and Electroanalysis.