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Operando Synthesis of Macroporous Molybdenum Diselenide Films for Electrocatalysis of the Hydrogen-Evolution Reaction

Saadi, Fadl H. and Carim, Azhar I. and Velazquez, Jesus M. and Baricuatro, Jack H. and McCrory, Charles C. L. and Soriaga, Manuel P. and Lewis, Nathan S. (2014) Operando Synthesis of Macroporous Molybdenum Diselenide Films for Electrocatalysis of the Hydrogen-Evolution Reaction. ACS Catalysis, 4 (9). pp. 2866-2873. ISSN 2155-5435. https://resolver.caltech.edu/CaltechAUTHORS:20140804-090046189

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Abstract

The catalytically inactive components of a film have been converted, through an operando method of synthesis, to produce a catalyst for the reaction that the film is catalyzing. Specifically, thin films of molybdenum diselenide have been synthesized using a two-step wet-chemical method, in which excess sodium selenide was first added to a solution of ammonium heptamolydbate in aqueous sulfuric acid, resulting in the spontaneous formation of a black precipitate that contained molybdenum triselenide (MoSe_3), molybdenum trioxide (MoO_3), and elemental selenium. After purification and after the film had been drop cast onto a glassy carbon electrode, a reductive potential was applied to the precipitate-coated electrode. Hydrogen evolution occurred within the range of potentials applied to the electrode, but during the initial voltammetric cycle, an overpotential of ~400 mV was required to drive the hydrogen-evolution reaction at a benchmark current density of −10 mA cm^(–2). The overpotential required to evolve hydrogen at the benchmark rate progressively decreased with subsequent voltammetry cycles, until a steady state was reached at which only ~250 mV of overpotential was required to pass −10 mA cm^(–2) of current density. During the electrocatalysis, the catalytically inactive components in the as-prepared film were (reductively) converted to MoSe_2 through an operando method of synthesis of the hydrogen-evolution catalyst. The initial film prepared from the precipitate was smooth, but the converted film was completely covered with pores ~200 nm in diameter. The porous MoSe_2 film was stable while being assessed by cyclic voltammetry for 48 h, and the overpotential required to sustain 10 mA cm^(–2) of hydrogen evolution increased by <50 mV over this period of operation.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://pubs.acs.org/doi/abs/10.1021/cs500412uPublisherArticle
http://dx.doi.org/10.1021/cs500412uDOIArticle
http://pubs.acs.org/doi/suppl/10.1021/cs500412uPublisherSupporting Information
ORCID:
AuthorORCID
Saadi, Fadl H.0000-0003-3941-0464
Carim, Azhar I.0000-0003-3630-6872
McCrory, Charles C. L.0000-0001-9039-7192
Soriaga, Manuel P.0000-0002-0077-6226
Lewis, Nathan S.0000-0001-5245-0538
Additional Information:© 2014 American Chemical Society. Received: December 16, 2013. Revised: July 17, 2014. Published: July 17, 2014. This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a U.S. Department of Energy (DOE) Energy Innovation Hub, supported through the Office of Science of the DOE via Grant DE-SC0004993. A.I.C. acknowledges a National Science Foundation Graduate Research Fellowship for support.
Group:JCAP
Funders:
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0004993
NSF Graduate Research FellowshipUNSPECIFIED
Subject Keywords:hydrogen-evolution reaction, synthesis of molybdenum diselenide, wet-chemical synthesis of layered electrocatalysts, mesoporous catalysts, synthesis of group VI dichalcogenides
Issue or Number:9
Record Number:CaltechAUTHORS:20140804-090046189
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20140804-090046189
Official Citation:Operando Synthesis of Macroporous Molybdenum Diselenide Films for Electrocatalysis of the Hydrogen-Evolution Reaction Fadl H. Saadi, Azhar I. Carim, Jesus M. Velazquez, Jack H. Baricuatro, Charles C. L. McCrory, Manuel P. Soriaga, and Nathan S. Lewis ACS Catalysis 2014, 4, pp 2866–2873
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:47873
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:04 Aug 2014 17:06
Last Modified:03 Oct 2019 06:57

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